Polar Electro RMCM-01 General Description Manual

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 Heart Rate Receiver

Component

Product code #: 39025074

KEY FEATURES

High Filtering Unit

Designed to work well
on constant noise fields

SMD component: To be installed
as a standard component to end
user circuit board.

Working solution with all Polar
transmitter belts

There is a possibility
that one software
modification is required
on training equipment

Differences on reception
range depending the
transmitter used

Receiver coil installation method
improved. Better towards
mechanical noise.

GENERAL DESCRIPTION

The Polar heart rate receiver component receiver
wirelessly receives the heart rate signal from Polar
transmitter belt. The complete heart rate measurement
system consists of three different parts; transmitter,
receiver and electronics and/or display device that is
outputting the heart rate value.

The transmitter, worn around the chest, electrically detects
the heart beat and starts transmitting a pulse corresponding
to each heart beat. The receiver that is installed on end user
equipment receives the signal and generates a
corresponding digital pulse that is operated on by the end
user equipment electronics.

Following picture illustrates the structure of measurement
setup.

Interface to
electronics

KEY BENEFITS

• Designed to be used in constant noise environment

• Small size, easy to find a place inside end user

equipment

• Working with all Polar transmitter belts

• SMD component for Pick & Place machine

• Coded and noncoded receiver

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT - SPECIFICATIONS

Beat-to-Beat Output
format

The receiver module has 2
different output pins, HR and
FPLS.

The HR output generates a 1ms,
3V positive pulse after the receiver
has locked onto a code from a
coded transmitter. If no coded
signal is detected, the receiver will
determine that a non-coded
transmitter signal is present and
output the data on the HR pin.

FPLS always generates pulses in
the same manner as Polar’s
standard OEM receiver modules.
All detected pulses are outputted.
For example, if a coded transmitter
is being used, there will be two
pulses (within 250ms) outputted.
Nominal pulse width is 6ms,
positive pulse, 3V.

The application where RMCM01
is connected should be able to
calculate the time between
incoming pulses and then use
suitable averaging to ensure the
best performance on outputted
heart rate.

System Description

A complete heart rate measuring system consists of a Polar
Transmitter worn around the chest and Polar RMCM-01
receiver built into the end user equipment. The Polar
Transmitter detects every heartbeat through two electrodes
with ECG accuracy and transmits the heart rate
information wirelessly to Polar RMCM-01 receiver with
the help of a low frequency electromagnetic field. The
RMCM-01 receiver receives the transmission, and passes a
digital pulse corresponding to each heartbeat to the end
user equipment electronics. The coils in the Polar
Transmitter and Polar RMCM-01 receiver must be aligned
parallel in order to gain optimum performance.

The end user equipment contains a microprocessor that
calculates current heart rate value based on the time
interval between the pulses sent by the Polar RMCM-01
receiver to the microprocessor. This calculation contains
certain amount of averaging, and other techniques, known
as an algorithm, to ensure a reliable and stable heart rate
reading.

The microprocessor of the end user equipment thus has the
following functions:

1. Receiving of the electric heart beat pulse from
the Polar Receiver

2. Calculating the times between the pulses

3. Performing the error checks

4. Calculating the heart rate

5. Sending the heart rate to the display

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SPECIFICATIONS

Placement of the receiver
component

The following rules and advice apply to
the placement of the Polar receiver
components. This verifying measurement
should be performed before the release of
final circuit board

• The distance from the transmitter to

the receiver should not exceed 80 cm.

• The orientation of the receiver is very

important. The coil axis of the
receiving coil has to be parallel with
the magnetic flow created by
transmitter in order to get optimum
gain for successful heart rate
measuring. In normal cases this means
that the axis of the transmitting and
receiving coils must to be parallel.
This is also illustrated in the following
picture. Coil is placed on the edge of
right hand side along the long side of
the RMCM01

• Metal casing may form a Faraday case around

the receiver thus attenuating the signal and
shortening the reception range. There may also
be an effect twisting the direction of the
magnetic field, thus possibly changing the rule
of parallel coil axis.

• Interference may be created by i.e. electric

motors and their control circuitry, multiplexed
display units, switching power supplies,
monitors or TV equipment causing difficulties
to heart rate measuring. Most disturbances are
both directional and distance related. An
optimum location for the receiver is where the
heart rate signal is maximized and the
disturbances are minimized.

The best cure is to maximize the distance between
Polar receiver and the source of disturbance, and at
the same time minimize the distance between Polar
Receiver and the Polar Transmitter.

Practical solutions can be discussed with Polar
engineering staff. Polar engineering also can, using
special equipment, find out the nature of the
disturbance, thus helping to cope with it.

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SPECIFICATIONS

Step by step procedure
for defining an optimum
location

1. Initially, without any heart rate
transmission, place a Polar Heart Rate
Monitor in possible and desired
location for the receiver. These tests
should be performed during operation
of end user equipment with light and
heavy loads. If the “!“ symbol in the
wrist receiver is blinking it means that
there are some occasional spikes
possibly decreasing reliability of heart
rate measuring. If heart symbol does
not blink it means that in most cases
there is no disturbances. In most cases
only way to eliminate interference is
to place receiver far enough from
interfering components.

2. At the next stage, keep receiver still at
the place defined in first step and turn
Polar Pulse Simulator on. If the “!“
symbol in wrist receiver starts
blinking regularly a good location for

the PCBA receiver has been located. If heart
symbol does not blink, the typical cause is that
electromagnetic noise causes saturation of
receiver circuit preventing successful heart rate
measuring. (Note: Simulator should be located
within approximately 2 feet from the receiver
for the test.)

3. Once a good location is determined, place the
RMCM-01receiver and connect it to end user
equipment electronics and receive heart rate
transmission from the Polar Heart Rate
Simulator. If RMCM-01receiver does not
generate corresponding pulses there may be
some problems in interfacing the receiver to
end user equipment electronics. System should
work also with chest belt.

4. Test RMCM-01receiver with chest belt and
check the reception range. The most reliable
way to define maximum range is to take the
Polar heart rate transmitter outside the reception
range and move it closer to receiver. Maximum
reception range is the distance at which receiver
generates pulses regularly.

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SPECIFICATIONS

Dimensions, Diagrams and Electrical Details

Dimensions Value

Board Length 17.8 mm
Board Width 15.3 mm
Board Height 5.2 mm

Pin name Description

HR Heart beat information

3V positive pulse, 1ms.
Reset Reset
OSC Crystal terminal
F32KIN Crystal terminal or DC

isolated clock input
OSC_ON Clock selection

(input/output)
WIDB_DET Settings. Connect to Vcc
FPLS Pulse detector output

3V positive pulse, 6ms

nominal width.
LX2 Antenna coil terminal
LX1 Antenna coil terminal
GND Ground
VCC Operating voltage

Parameter min typical maximum Unit

Reception range (T31 typ.) 80 92 100 cm

Operating voltage 2.5 3.0 3.4 V

Operating current @ 3.0V 60

µA

Output high voltage @ 3.0V 2.4 V

Output low voltage @ 3.0V 0.4 V

HR output width 1

ms

FPLS output width 6 ms

Reception frequency 5.5 kHz

Operating temperature 0 20 60

°C

Crystal input (sinusoidal) * 0.2 3.0 V

Crystal input (square) ** 3.0 V

Crystal input frequency *** 32.736 32.768 32.800 kHz

Storage temperature -30 20 70

°C

*) Peak-to-peak voltage value. Do not exceed the supply rails [0, Vcc] V.
**) Square wave input between 0V and Vcc. Do not exceed the supply rails [0, Vcc] V.
***) Tolerance for crystal is 1000ppm.
Note: Crystal duty cycle has to be between 40-60%

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SPECIFICATIONS

Detailed pin descriptions

HR – Outputs heart rate value as positive pulse
on each heart beat. Startup delay 5 seconds on
coded signal, 15 seconds on non-coded signal
Reset – Pulling down this pin causes the heart
rate receiver reset itself. Recommendable pull
down resistor value is 1k".
OSC – Crystal terminal. This pin is used if
external 32kHz crystal is used.
F32KIN – Crystal terminal or clock input. If
32kHz clock is available on the end user
board, the clock signal can be inputted on this
pin. Note that signal has to be DC blocked.

OSC_ON – Connect pin to ground if external
clock is used. Connect to Vcc if crystal is used.

WIDB_DET – This pin is connected to 3V.
FPLS – Detector output. On this pin all the

detected pulses are shown. No startup delays
on outputting.
LX2 – Antenna coil terminal. If range is too
high, a resistor is connected between this pin
and LX1 pin.
LX1 – Antenna coil terminal. If range is too
high, a resistor is connected between this pin
and LX2 pin.

GND – Power supply ground pin.
VCC – Power supply voltage pin.

Application note for typical connections

Display device or console

Gnd

Vcc

Gnd

Vcc

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SPECIFICATIONS

Display device or console

Vcc

GND

Vcc

1k

1k

32.768kHz 30ppm
HFC-150 Seiko

Load capacitance

12.5pF

Adding Heart to Your Technology

Polar Electro Inc - OEM Division Polar Electro Europe BV

1111 Marcus Avenue, Suite M15 Gotthardsstrasse 3
Lake Success, NY 11042-1034, USA CH-6300 Zug, Switzerland
Tel. [phone] Tel. [phone]
Fax. [phone] Fax. [phone]

RMCM-01 RECEIVER COMPONENT – SOLDERING PROFILE