Eggtimer Rocketry Proton User Manual

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Eggtimer Proton

User’s Guide

Board RevA9

Software Rev. 1.01A

© 2018 Eggtimer Rocketry
All Rights Reserved

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Eggtimer Proton Features

WiFi-Enabled, SIX-Output logging flight computer with 120G Accelerometer

Flexible deployment and arming modes, to handle virtually any flight scenario

Any channel can perform any function… no dedicated "Drogue" or "Main" channels

First three channels can be set for standard servos during deployments, variable servo travel

Programming, arming, and downloading can all be done with any WiFi/browser-enabled device

No apps required on your device, just a browser

Size: 3.25” x 1.3”, fits easily in a 38mm coupler tube, weighs about 20 grams

Altimeter records data up to 60,000’

Detailed flight data for 14 flights is saved, and can be downloaded using your browser

Summary data can be downloaded or viewed on your browser, immediately after the flight

Fully “mach immune”, deployments are inhibited until the rocket is moving slowly near apogee

Battery input is fully polarity protected

Works with a 2S/7.4V LiPo battery, 300 mAH or more recommended

Optional separate battery input for deployment channels protects against “brownouts”

Works with almost all common deployment devices, will even light an Estes® igniter with a 2S LiPo

Each output channel can handle up to 10A/40V, system capacity 30A

Test mode so you can do an actual pyro test remotely up to 200’ away from your rocket

Dual-ended deployment outputs, igniters are essentially “dead” until well into the flight

No switch needed, since it’s disarmed and the igniters are dead until YOU arm it

“Fail-Safe” mode can fire main chute (in deployment mode) if a drogue failure is detected, preventing a
potential high-speed chute deployment or crash

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Disclaimers, Legal Stuff, Etc.

The Eggtimer Proton is meant to be used for hobby and experimental rocketry purposes.
Although hobby rocketry has an admirable safety record, largely due to the efforts of the good
people at the National Association of Rocketry (NAR) and the Tripoli Rocketry Association
(TRA), rocketry can be dangerous if proper safety precautions are not observed. This is
particularly true with some of the advanced techniques like pyrotechnic parachute deployment
and airstarting motors. People can and have been seriously injured by not following recognized
and accepted safety practices. We cannot be responsible for your actions.

We strongly recommend that if you are not a member of either the NAR or the TRA, you join
one of them, join a local rocketry club, and pick the brains of experienced members before you
try any kind of electronic deployment or airstart flight. The safety information included in these
instructions is by no means comprehensive or complete, and is no substitute for the supervision
and advice of experienced rocketeers.

Limited Warranty

Eggtimer Rocketry warrants that all of the parts on the packing list of this Eggtimer Rocketry kit
have been included, and that they are all in working condition. If you are missing something,
contact us immediately at [e-mail] and we will send you whatever it is
that you are missing. If you are missing something really egregious (like the PC board or the
processor, for example), we may ask you to return the entire kit unbuilt, we will send you a

prepaid shipping label for this purpose. We’d especially like to see the packing list so we can
figure out what went wrong so it doesn’t happen again…

If your Eggtimer Proton does not work properly after assembly, take a deep breath, get out the
magnifying glass and a good light, and see if you have inadvertently created a solder bridge
somewhere. Chances are pretty good that you have, or that you have installed a part incorrectly.
We are a very small company and we just don’t have the resources to repair your board, but we
will be more than happy to give you advice and we might be able to help you find your error if
you send us some high resolution pictures, to [e-mail] . We cannot take
responsibility for your assembly techniques; if you do not have experience building kits of this
nature, we recommend that you enlist some help. (Another reason for joining a rocketry club,
there is usually at least one electronically-inclined member who can be bribed with a beverage or
two to give you a hand. Engineering types love a challenge, especially it it’s easy for them but
hard for you.)

Eggtimer Rocketry warrants that when properly assembled this Eggtimer Rocketry product will
perform substantially according to the published documentation. This means that we spent a lot
of time trying to ensure that it’s going to work the way that we say it does, and we try to fix
things that don’t quite work right in a reasonable time. Nevertheless, we can not and do not
warrant that this product is perfect and will meet every rocketry purpose, for the simple reason
that we can’t test every possible rocket/motor/environmental combination. It is the buyer’s
responsibility to determine the suitability of the Eggtimer Proton for their particular purpose. If
you have a problem with this, please contact us and we will be happy to send you a prepaid
return label for your unbuilt kit and we will refund the purchase price on receipt of your kit.

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Meet the Eggtimer Proton

The Eggtimer Proton is an advanced hobby rocketry flight computer with a barometric pressure
sensor, 120G accelerometer, and six high-current output channels. Its job is to properly deploy
your parachutes and bring your high-powered rocket safely to the ground, and to record flight
information for later analysis. In addition, it can handle other events such as airstarting motors
or just about any other event that you can come up with. Each channel can be programmed
independently for whatever function you need. In addition, channels can be "clustered" so that a
single event triggers multiple channels, perfect for cluster airstarts. Channels can be triggered by
a number of different events for an almost unlimited combination of scenarios.

It’s nice to get your rocket down in one piece, but it’s also nice to know how the flight went.

The Proton can record your last 14 flights, and you can easily view and/or download both
summary statistical information and detailed time vs. event information. The detail output
format is a standard .csv file, which can be imported into virtually any data analysis program.

What makes the Proton different from most other flight computers is that it has a WiFi interface.
Instead of using switches, jumpers, or a data cable to your laptop to program it, you simply
connect to it with your phone, tablet, or computer using WiFi and a browser like Safari, Firefox,
Internet Explorer, or Chrome. You remotely arm it at the pad using your handheld device too, so
for many applications you do not need a mechanical switch… it won’t turn on until you tell it to.
Flight data is downloaded to your handheld device using WiFi, and with the installation of an
appropriate spreadsheet or other data analysis program you can actually get a flight graph within
seconds of recovering your rocket.

Since one of the tenants of successful electronic deployment is ground testing, the Proton
incorporates a ground-test feature so that you can check YOUR battery with YOUR igniters to
make sure that they are compatible and will work in flight. This is done remotely over WiFi, so
you can even test with “live” pyro charges, standing up to 100’ away from your rocket.

The output channels are capable of triggering just about any load that you’re likely to encounter,
we’ve even fired a medium-current Estes igniter with it using a 2S/7.4V LiPo. You can set the
output on-time from 1-9 seconds, so it’s ideal for use with a hot-wire non-pyro deployment.

There’s a separate battery input for the deployment circuitry, so you can optionally use a second

battery on the deployment outputs that 100% guarantees that a deployment glitch will not cause
your Proton to “brownout” due to low voltage. Each channel is overload protected so they can't
be blown out with an accidental short.

You can also use standard PWM hobby servos with the Proton, for non-pyro deployments. This
makes it ideal for use by TARC teams that want to experiment with electronic deployment but
can’t use pyrotechnics, or for flights over 30,000’ in which pyro charges may not be effective.

In addition to deployment functions, the Proton can also be used to “airstart” additional motors in
flight, either for “strap on” boosters or for starting a second stage motor. It works as a timer that
starts at launch, and is qualified by breakwire support, velocity-at-time, and/or altitude at time.
There is also a Barometric-Altitude-Deviation calculation that won't fire your airstart motor if
the rocket is moving off-axis. This helps ensure that your second stage won’t light unless your

rocket is going “up”.

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Getting to know your Proton

Although the Proton seems relatively simple, you will want to familiarize yourself with it
BEFORE you install it in a rocket, and certainly before you try flying it.

Battery (BATT) – Two solder pads for connecting the Proton’s battery. It's polarity protected,
so if you hook up the battery backwards it won't damage anything. We recommend a 2S/7.4V
LiPo battery, 300 mAH or higher… more on that later.

Buzzer - “Beeps” out status, warnings, apogee at landing, and other important notifications.

Output Channels (CH1-CH6) - Six sets of deployment output terminals, each with a 10A/40V

capacity.

Battery Output (B+) – Used for the single-battery option when jumpered to the DP+ pad.

Deployment Power (DP+/DP-) – Two solder pads for connecting a separate deployment

battery. If you choose to use the Proton with a single battery for both the computer and the
deployment side, you simply jumper the DP+ pad to the B+ pad, which provides the power for
the deployment channels.

Servo Outputs - Three pads marked "1" through "3", and one labeled "G", for connecting logic­level servos. These are mirrored to the CH1-CH3 output channels.

Programming Cable Header – 3-pin header that’s used with an Eggtimer USB-Serial cable for
updating the software or for viewing the WiFi passkey (in case you lose it).

Programming Jumper Pads (PGM) – Two pads used to put the Proton into programming
mode at boot-up, for uploading software updates. Normally you won’t do anything with these
pads.

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Mounting Your Eggtimer Proton

IMPORTANT: Your Proton must be mounted so that the "UP" labels on the board are
pointed towards the nose cone of your rocket!

The Proton is relatively small and light, and can be mounted several ways. The most common
way of mounting it is using four #4 screws, either self-tapping screws for wood sleds (put a drop
of CA glue in the hole first to prevent the screws from loosening in flight) or machine screws
(we recommend using Nylon-insert nuts so they don’t come loose). We recommend that you use
Nylon washers between the board and the screw heads to prevent any possibility of shorts.

You’ll also need to put some kind of spacer between the bottom of the board and the sled, about

3/16” high. There’s a mounting template on the Eggtimer Rocketry web site to help you plan

your installation.

We do NOT recommend using double-sided foam “servo” tape to mount the Proton to your AV

sled. There are parts on both sides of the board, so the bottom isn’t flat. You won’t get 100%
coverage with the servo tape, so there’s a potential for it coming loose in flight, which is bad.

Also, when you pull it off, you might lift a part off the PC board… that would be bad too.

However you mount it, be careful not to overtighten the screws and possibly bend the circuit
board. The parts on the bottom of the board can break if you force them against the bottom of
your sled… don’t ask us how we know. We recommend that you leave a little space between the
board and the sled… about the thickness of a credit card.

The Proton should be mounted so that the "UP" markings near the WiFi module face the nose of
your rocket. You also want to make sure that the holes are drilled properly so that it faces as
vertically as possible. If you get it a tiny bit crooked it's not going to matter much, but the more
care that you put into the mounting the better your results will be.

Since the Proton primarily uses a barometric pressure sensor to determine altitude, you’ll need to
drill a few holes in your AV bay to vent it to the outside air. There’s a lot of debate about what
the right size for the holes is, how many, etc., but the most accepted rule of thumb is: One ¼”
diameter hole for every 100 square inches of AV bay volume. For most average AV bays that's
going to be three 3/32" to 3/16" holes.

Now the tricky part is that you don’t want ONE vent hole… the optimum number is THREE,

equally spaced along the AV bay perimeter. This works out to about three 5/32” holes for every

100 square inches of volume. That’s just about the size of a 4” diameter AV bay that’s 8” long,
so you can work up or down based on that. We also recommend that you don’t mount it so that
the pressure sensor is directly across from the vent holes in your AV bay. You can get funny
currents during flight, which may compromise the accuracy of the altitude readings.

Wiring Your Eggtimer Proton

The Proton is designed to have the power connector wires directly soldered to the board, and
outputs connected using the screw terminal blocks. You can also omit the terminal blocks for
the outputs and solder pigtails to the output pads on the board, so you can use whatever method

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of terminating the connections you want: barrier strips, solder directly to pigtails, through­bulkhead terminals, etc. Soldering connections to the board prevents the connections from
coming loose in flight due to vibrations and G-forces.

We’ve found that simply wire-wrapping the igniters to a “pigtail” wire soldered to the board
works very well for smaller rockets. By soldering the pigtails to the board rather than having
screw terminal blocks, you eliminate the possibility that the wire may work loose from the
terminal in flight. It saves space too, which is usually at a premium with 38mm and skinnier
rockets. We also like the wiring kits sold by Binder Design Rocketry, the wire they supply is
Teflon-jacketed and lends itself well to solder-type wiring. Their charge wells with integral
through-bulkhead terminals als work great for 39mm-54mm rockets.

We recommend using #22-#26 gauge wire for wiring to the Proton board, we like to use the #24

gauge stranded wire that’s found in Cat-5 network cables. It’s cheap, easy to find, and just the
right size. It’s also twisted together in nice solid-striped pairs, so it’s easy to tell the “+” from
the “-“ wire. If you can, get the “plenum” cable, since it has a Teflon jacket and doesn’t melt as

easily when you solder to it as the standard “riser” cable. You can also use solid wire, but solid
wire is harder to work with and has a tendency to break after being bent a few times. These
breaks can be a pain to find, because they are typically inside the insulator jacket where you
can’t see them.

If you use stranded wire, you MUST TIN THE WIRES BEFORE SOLDERING TO THE

BOARD. This is to prevent stray “whiskers” of wire strands from coming loose and bridging
pads, or breaking off and landing on the board in some random place. We’ve seen the results of

this happening, it’s not pretty, and they can be very hard to find if the lodge underneath the

processor chip or in some other hidden spot on the board.

If you build the board with the terminal block option, be sure to tin whatever wires you are using
for your igniters before you insert them into the terminal block. Loose strands here can prevent
deployments, if a strand comes loose and lodges in the wrong place it could cause an immediate
deployment when you connect the battery. That would be bad…

Last, but not least, we strongly recommend that all wiring on your sled be zip-tied to the sled so
that there’s no chance of any wires coming loose in flight. We’ve seen it happen, and the results
are not pretty.

The Single-Battery Option

For a single battery, you only need to solder a jumper (or switch, see below) between the B+ and
DP+ pads that are located next to the two BATT pads. This will provide power to the
deployment circuitry directly from the battery. Nothing else is necessary... see the picture below.

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The Dual-Battery Option

Using separate batteries for the Proton’s computer and deployment side has some advantages,

and one disadvantage. The disadvantage is that it’s going to take more stuff… one more battery,

one more connector, and possibly, one more switch. The advantages that: 1) You can use a
different voltage battery than the computer side, which you may want to do for servos; and (the
big one) 2) No matter what happens on the deployment side, including a complete loss of battery
power, it’s not going to affect the computer side. This is the same philosophy behind the dual­battery architecture on other Eggtimer Rocketry flight computers such as the Eggtimer Classic
and the Eggtimer TRS.

Some other flight computers use a big capacitor on the power output, with a single battery to
prevent brownouts. This protects against momentary disconnects such as a glitch due to G­forces when your drogue deploys, but it won’t protect against a longer-term brownout such as a
shorted ematch after firing. Once that capacitor drains, your altimeter is done. With the dual-

battery setup, if you have a short on the drogue it’s going to cause a high current drain for a few

seconds until either the processor shuts the output transistor off, or until the transistor blows (not
likely, by the way). Either way, that high current draw is going to stop. Unless your battery gets
totally fried during these few seconds (also not very likely…), when the command is sent to the
main to fire it’s going to work.

To wire up your Proton for dual-batteries, wire the +/positive side of the battery connector to the
DP+ pad (next to the BATT pads), and the -/negative side of the battery to the DP- pad (located
between the deployment output pads). Leave the B+ pad unconnected. If you are going to be
using a separate disconnect switch for the deployment battery you will generally wire it in series
with the +/positive side, so that it goes between the DP+ pad and the +/positive lead of your
battery connector.

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If you use a separate deployment battery, remember that you will not see continuity on either
channel until you power on the deployment battery. If you use a switch, we recommend that
you turn it on to test igniter continuity at your work table BEFORE you add the pyro powder to
your charge wells, then shut it off until you’re safely on the pad. Turning on the deployment
power does NOT power on the deployment FET; it only allows the trickle current to go through
the circuitry to test continuity.

About Switches…

The Proton is designed so that it will not self-arm itself. If you power it up, it will sit there on
the Status page forever, changing the validation code every 60 seconds… you have to actually
arm it using the validation code in order to start a flight. In addition, the unique dual-ended
deployment output prevents any significant current from getting to the igniter until it’s armed
and actually in-flight.

Because of this, for most flights using electronic deployments up through NAR/TRA Level 2
you do not necessarily need a separate power switch if you’re using the single-battery option.

You can simply connect the battery to a locking connector such as a JST connector and you’re

ready to go until you arm it on the pad. This makes your AV bay build easier and smaller, and of
course it makes your pre-flight procedure a lot simpler.

The Proton is different than most other altimeters because it has dual-ended switching on the
deployment outputs: BOTH the “+” and the “-“ side are switched off, leaving the igniter
essentially dead until it's actually in flight (except for a tiny trickle current that’s used to test
continuity). For the igniter to fire, both sides have to be activated independently, and this can’t
happen until you’re in the air and the deployment enabling logic has been triggered.
This meets the NFPA and Tripoli/NAR requirement that pyrotechnics be de-energized until
ready for flight. However, FOR LEVEL 3 CERTIFICATION FLIGHTS ONLY you may need
to add a switch to the pyro outputs. As of the date of publication (Sept. 2018) Tripoli allows
electronic switches for L3 certification projects, subject to the approval of the TAP's. NAR
requires a mechanical disconnect for L3 certification flights.

In the event that you do decide to add a switch, you have a few options, since the Proton can use
a separate power supply for the deployment devices.

If you are using a single battery for both the computer and the deployment side and you need to
use a deployment disconnect switch, you can simply put a switch between the B+ and DP+ pads
instead of a jumper. Turn on the switch when you’re on the pad to power up the igniters,
confirm that everything is OK, then arm your Proton and go.

If you are using a separate battery for the deployment side, you can put the switch in series with
the deployment power that goes on the DP+ pad. This is our recommended configuration for
Level 3 rockets because having the separate deployment battery 100% prevents any kind of
deployment glitch from affecting the flight computer side. Doing it this way allows you to
make whatever changes you may need to make (for example, lowering the Main deployment
altitude if the wind picks up a bit) while leaving the deployment side powered off.

Whatever switch you use, make sure that it can handle the expected G forces that you expect the
rocket to experience during flight. In general, we recommend that if you use a slide switch that it

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is mounted so that it slides sideways, not up and down. This will prevent G forces from possibly
causing the switch to “bounce”, interrupting the power to the Proton, which is not a good thing.
Any slide switch that you use must be rated to at least twice the G forces that you are likely to
see… a $1 Radio Shack special isn’t going to cut it, spend a few bucks and get a high-quality
switch.

You can also use a “push-on, push-off” type switch. Many users have had good success with
them, also mounted laterally. You can put the switch just behind one of the air ports, and actuate
it by pushing a small pin/wire through the hole. Just like with slide switches, spend the money to
get a good quality switch.

A better option would be a more positive switch, such as a rotary switch or a screw-type switch
that locks down positively. Since the major forces on rockets are almost entirely along the
longitudinal axis of the rocket, the contacts on a rotary switch are unlikely to be interrupted by G
forces. A popular choice is the Schurter 033.4501 rotary switch, they cost about $5. This is a
special-purpose rotary switch originally designed to be a 120v/220v power supply selector
switch, but it works very well for our purposes. You can get them from a number of online
rocketry suppliers, or you can order one directly from Allied Electronics, a direct distributor for

Schurter products. They’re actually about a buck cheaper from Allied, but you’ll have to pay

shipping, so chances are pretty good that you’re gonna come out ahead if you buy it from one of

the rocketry suppliers because you’re probably buying a bunch of stuff from them anyway.

Featherweight Rocketry and Missile Works also make good small screw-type switches, they use
a screw to positively lock down the contacts and completely eliminate any possibility of the
switch being jarred open. You can also make your own screw switch, Google around and you
can probably find some good examples.

Finally, if you want to avoid moving contacts altogether, check out our Eggtimer WiFi Switch
(www.EggtimerRocketry.com). You can turn it on or off using your mobile device too,
independently of your Proton. It may be a bit larger than other switch options but the
convenience of not having to fumble around looking for the switch inside the AV bay more than
makes up for the minor weight and size penalty, and you can safely arm your deployment
electronics from up to 200’ away from your rocket. And yes, the WiFi Switch will not interfere
with the WiFi signal from your Proton.

Proton Battery Options

For most installations, we recommend using a 2S 7.4V LiPo battery. You’ll need one that’s at
least 300 mAH, since the Proton draws 85 mA (it’s WiFi… that’s the nature of the beast). You
CAN get away with smaller batteries, IF (and ONLY IF) you connect the fully-charged battery
up right before flying. We’ve used batteries as small as 180 mAH in testing, but we have several
fully-charged batteries on-hand and we change them with a fresh one after each flight. With a
larger battery, you can take your time… a 500 mAH 2S LiPo is about the same size and weight
as a 9V alkaline battery, and will last all day. That’s what we use for all but the skinniest of
rockets. For 3" or larger diameter rockets, we like the skinny packs used for Airsoft guns…

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they’re about 100mm x 18mm x 12mm, so it’s easy to fit them on the back of the sled, and they
have a lot of capacity… about 1200 mAH. You can run all weekend on one charge.

While we’re on the subject of 9V alkaline batteries, DO NOT, repeat, DO NOT use a 9V battery

to power the Proton. At all. They don’t source much current, especially compared to a 2S LiPo.
While it will appear to work fine once it’s new, it will quickly drain, and you will find that the
range starts to rapidly decrease, and the Proton will appear to become unresponsive. If you’re
using the single-battery option, the chance of a low-voltage “brownout” is much higher than it
would be with a 2S LiPo. WiFi takes a lot of power, so make sure you feed it well.

In addition, if you are using a single battery we recommend that the current-sourcing capacity of
the battery should be at least 5x the all-fire current of the igniter (or the sum of the igniters, if
you're firing a cluster), to prevent any chance of the voltage dipping. To get that number,
multiply the capacity in mAH by the “C” number of the battery. For example, a 300 mAH
battery rated at 20C will easily put out 6,000 mA, or 6A. If you igniter is rated for 750 mA all­fire, 5 x 750 = 3750 mA, so that 300 mAH/20C battery would be just fine.

If you’re using a separate battery for the deployment side, whatever battery will fire your igniter

or operate your other deployment device (hot wire, servo, etc.) is fine. Little 1S 3.7V 150 mAH
LiPo batteries work great with most ematches, and are so small that you can easily mount them
with a little servo tape just about anywhere you want in your AV bay. The output drivers will
each handle up to 10A and 40V, so if you have something really power-hungry (like a solenoid,
for example), you can simply use a bigger battery. You don't have to worry about "burning out"
the drivers, because they're internally current-limited and thermally-protected; if you try to push
too much current through them, they'll simply shut off until they cool off (kind of like a thermal
circtuit breaker).

You can use a 9V alkaline battery too for the deployment side only with a dual-battery setup
if that’s what you like, just be aware that they’re pretty big and heavy by contemporary
standards. If you do use a 9V battery, one more thing you need to be careful about is that some
brands of 9V batteries simply have cells pressed together in a metal case, so high G forces can
cause the battery to fail. If you absolutely HAVE to use a 9V battery, we recommend Duracell
9V batteries, because they use welded cells internally and are less likely to come apart than some
other brands. If you do decide to use an alkaline 9V battery, we recommend that you replace it

after EVERY flight. Yes, that can get expensive. And yes, you don’t have to worry about your

battery having been drained too much by a previous flight… enough said.

Regardless of what kind of batteries you choose, charge or swap out your batteries before
every session, and check the voltage with a digital voltmeter before every flight. The

voltage check on the Proton is only on the processor battery, it does not test the deployment
battery (assuming it’s separate). You don’t want to spend all the time to find the “perfect”
battery combination for your 54mm minimum-diameter mach-buster only to realize after you dig
it out of the ground after lawn-staking it that you forgot to charge the deployment battery.

Although you probably won't hurt the Proton itself by dead-shorting the outputs, the voltage drop
due to the short may cause the battery voltage to drop low enough to cause the processor to reset,
although the drivers have a low-voltage cutoff at about 4V that's designed to prevent this from
happening. This is why we recommend having a battery current capacity of at least 5x the all­fire current of your igniter; if you get a short, chances are that the battery is going to simply
generate a little heat in the drivers and wires for the few seconds that it’s on, then it will be

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turned off and everything will be OK. If you battery only has a marginal current capability, the
same short may cause the Proton to reset if the voltage drops below the processor threshold
(about 2.8V). The deployment drivers are designed to shut down if the source voltage drops
below 4V, so that theoretically shouldn't happen, but it's better not to chance it. Depending on
when this happens, the effect could range from not getting your peak altitude reading (annoying),
to deploying only the drogue chute (if this happens when you fire the drogue), to a lawn stake if
you’re only using the drogue function and it fails to fire. Ouch. So, choose your battery wisely
if you're using a single battery.

If you’re using an ematch, you only need to set the deployment on-time to one second… if they
don’t fire in a few dozen milliseconds they probably won’t fire at all. If you’re using a hot-wire
(for example, to cut a cable tie or nylon fishing line) you’ll need to experiment with the on-time.
You’re going to want to do this on the ground, of course… flight-time is NOT for experimenting

with your deployment parameters!

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Using your Proton

What sets the Proton apart from other hobby rocketry flight computers is that it doesn’t use any

switches, jumpers, or cables to configure or download flight data. It’s all done over a WiFi

connection to your handheld device, using a common Internet browser. The pages have been
written very simply so that they do not require Java, Javascript, .NET, or any other scripting
language to operate… they’re all just simple HTML 1.1. The pages are simple text with minimal
formatting, and while they may not be particularly pretty they are very easy to read, and they
render virtually the same on every browser and platform we’ve tested.

About Browsers and OS’s…

All of the Proton’s functions will work almost identically with just about any browser that you
use. Because of the differences in the way that browsers display things and handle downloaded
files, however, you may find that one browser works better than another with your particular
platform. Interestingly enough, some browsers are much faster than others… generally the ones
that are provided by the vendor. Go figure…

In general, our recommendations are as follows, in order of preference:

Apple iOS: Safari, Firefox
Android: Firefox, Safari (yes, it’s an old version…), Chrome
Windows: Internet Explorer, Edge, Firefox, Safari, Chrome

Note that Chrome comes out last on all of these lists. The reason is that Chrome does not handle
the flight detail download function very well. In particular on an Android it can’t tell what to do

with the .CSV file that’s generated from the flight detail download, so it either hangs for awhile

or comes right back and does nothing. It’s a shame, because we really like Chrome, but for this
application it doesn’t work very well. If you have an Android, use Firefox instead, it will display

the .CSV file and launch your viewer if you have one installed.

Individual notes regarding browser compatibility and issues are in Appendix D.

Connecting to Your Proton

Each Proton has its own WiFi SSID network name, which is going to looks something like

Proton_2abcd

The last 5 or 6 characters are derived from the unique MAC address of the Proton’s WiFi
module, so they’re pretty much unique. The Proton uses the WPA2-PSK WiFi connection

protocol, so you need to enter an 8-digit passkey to connect. The passkey for your Proton is on a
label on the WiFi module that you got when you built it. It’s also on a label on the package. If
you accidentally lose it, you can also get it by connecting an Eggtimer USB-TTL data cable to
the programming header. See the Appendix for instructions on how to do this. We recommend

that you put a label on top of the WiFi module with the passkey… you’ll be glad you did at some

point.

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To connect to your Proton, hook up the battery and wait about 10 seconds for it to initialize.
You’ll hear some beeping as it goes through its self-test, and at the end of the long 3-second beep
it should be discoverable over WiFi. Go to the WiFi Settings on your handheld device, and
browse the wireless networks. You should see your Proton listed as something like

“Proton_1a2b3c”. Choose that network, and enter the passkey when prompted. Hint: When

asked, be sure to check “save the password” and/or “connect automatically when in range”. This

will keep you from having to do this every time. Note that if you have multiple Proton’s you
might NOT want to save the passkey… keep it handy by using a memo pad app on your device.

Open up your browser. If your home page is something on the Internet, you’re gonna get a
“Page can not be displayed” message because you’re connected to your Proton, not the Internet.
That’s OK and normal. Set your browser to the Proton’s home page:

192.168.4.1

and you should see the Status Page. At this point, you should Bookmark this page so you don’t
have to re-enter the address every time… you’re going to be going here a lot.

The Status Page

The first thing you will see is the Status Page. It tells you what your Proton is doing, and gives
you some other important information:

◦ Device Name (important if you have more than one of them in your rocket!)
◦ Flight Status: Armed or Disarmed
◦ Deployment channel status, settings, and link to change the settings (see below)
◦ Computer-side battery voltage
◦ Above-Sea-Level (ASL) altitude
◦ G's from the accelerometer (should be about 1.0 for vertical and 0.0 for horizontal)
◦ Temperature (it may read low for awhile… it takes 10-15 minutes to stabilize)

For arming:

◦ The current validation code (it changes every 60 seconds that you’re idle)
◦ A text box to enter the validation code into for arming
◦ An “ARM” button for arming (once you type in the validation code)

Links:

◦ Deployment channel “Change” links – for changing deployment channel in-flight settings
◦ Settings – takes you to the Global Settings page
◦ Flights – takes you to the Flight Select page, for displaying saved flight info

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Proton_2abcd 1.01a
Status: Disarmed

Validation Code:
4567

…………………………

ARM

Channel 1: Drogue Change
Delay: 0.0 Settings
Channel Status: ON

Channel 2: Main Change
Altitude: 500 Settings
Channel Status: ON

Channel 3: Airstart
Delay: 2.2 Settings
Channel Status: OFF

Channel 4: OFF Change
Channel Status: OFF

Channel 5: Clustered Change
Channel: 3 Settings
Channel Status: OFF

Channel 6: Off Change
Channel Status: ON

Battery: 8.0v
ASL Alt: 1050 ft
Accel: 0.03 G Calibrate
Temp: 74.2

Settings Flights

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Depending on what you have hooked up to the deployment channels and how it’s powered, you

may see the deployment channel status displayed in different colors. The colors are:

◦ Silver – Status does not affect arming (channel turned off, for example)
◦ Aqua - Good deployment status, i.e. channel is enabled and you have continuity
◦ Red – No continuity on enabled channel, arming not possible

The Proton updates the deployment status every time that the page refreshes. If you leave the
page alone, it will refresh every 60 seconds. When it refreshes, you’ll hear a little beep from the
speaker... this also lets you know that you’ve got power and are connected to your Proton. In
addition, every time the page refreshes a new validation code is created. You can force a page
refresh by hitting the refresh icon on your browser, or by clicking on the ARM button without
entering a validation code or entering an invalid validation code.

Calibrating the Accelerometer

You will notice that no matter which position you hold the Proton at after power-on, the Accel
number will be in RED. This is because the accelerometer has to "warm up" after power is
applied before the readings become stable; up until that point, the readings may drift from the
"actual" value. Once the accelerometer stabilizes, it can be used for flight, but first it needs to
be calibrated to compensate for whatever drift may have accumulated during the five minute
warm-up period. You CAN NOT arm the Proton for flight until the accelerometer has been
calibrated...

YOU NEED TO CALIBRATE THE ACCELEROMETER BEFORE EVERY FLIGHT

To calibrate the accelerometer, set the Proton horizontally; assuming that it's mounted in your
AV bay, just lay your AV bay on the table. Click on the "Calibrate" link next to the Accel
reading on the Status Page. If you do not see a "Calibrate" link, that means that the warm-up
period hasn't been reached yet... just be a little more patient. The warm-up period is five
minutes, so it shouldn't be long. Once you click on the Calibrate link, you'll see this screen:

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Proton_2abcd 1.01a

Accel Calibration

Lay your Proton
HORIZONTALLY
then click on the button below

Current Accel: 0.03 G

Auto-Adjust v

Calibrate

The default Option is to auto-adjust the calibration, which will take a reading and subtract it from
zero (since you're horizontal...). This is what you should choose if you are going to fly. When
you click on "Calibrate", the accelerometer offset will be calculated and it will be used from that
point on until you reset the power; you will be then be returned to the Status Page.

You can also click the down tick next to Option and select "Zero Offset"; that will zero the
offset, allowing you to see what the uncorrected Accel value will be on the Status Page. If you
do that, you will need to go back to the Calibrate link and select Auto-Adjust; the Proton WILL
NOT ALLOW YOU TO ARM if you select Zero Offset. It's strictly for your edification...
sometimes it's interesting to see how far the accelerometer has drifted.

Arming Your Proton

In order to start a flight, you need to arm the Proton. For safety reasons, the Proton will not self­arm; that is, you must go to the Status page and arm it by entering the current Validation Code in
the text box and clicking on the Arm button for the flight sequence to begin. This is different
than most other flight computers, which will automatically go into an arming sequence a short
time after powering up, assuming that the continuity is OK. The Proton is a little bit different

because it’s assumed that you’re not using a power switch so you are basically using the arming

sequence as a remote switch. This is the reason why we have the dual-ended switching
architecture; it ensures that your ematch/igniter is essentially “dead” until the Proton has been
armed AND you have a flight in progress. This virtually guarantees that you cannot fire a
deployment charge (or an airstarted motor...) on the ground.

Before you can arm the Proton, any enabled deployment channels must be in a flyable status.
This means that if a channel is enabled there must be continuity; if a channel fails the continuity
test then you will not be able to arm your Proton. You can tell very easily from the Status page if
it’s ready to fly, because any failed channels with have the continuity status highlighted in RED.
Note that if you've selected a servo deployment option the status will always be in GREY; there's
really no way to tell if a servo is connected or not, because they're an output-only connection.
It's assumed that they are always in a flyable state.

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In addition, your rocket must be in a vertical state, i.e. it must be pointing "UP" to arm it. If the

Proton_2abcd 1.01a
Status: ARMED

Please CLOSE
this Page!

Battery: 8.0v

Proton_2abcd 1.01a
Status: ARMED

Validation Code: 8509

…………………………

DISARM

Battery: 8.0v

Proton sees that the G's are under 0.80G or over 1.20G it will not arm. Note that the
accelerometer will drift over time, so you need to perform a calibration before you fly it in order
to compensate for this. See the previous section regarding accelerometer calibration.

To arm the Proton, enter the 4-digit validation code into the text box then click on the ARM
button. After about 5-10 seconds you should see an arming confirmation page:

This page looks a lot like the status page, but the status is changed to “ARMED”, it doesn’t

initially have the validation code/box, and only the battery voltage is displayed. A few seconds
later you should start hearing the buzzer beep about once per second. This is an audible
confirmation that the Proton is now in flight sequence mode, and you’re ready for launch. At
this point you should CLOSE the browser window on your handheld.

Until the flight actually starts, the Proton will be listening for activity from your handheld. If
you refresh this page or re-connect you will see the same page, but with a validation code, text
box, and “DISARM” button, as shown below: