Texas Instruments EK-LM4F232 User Manual

Download

EK-LM4F232 Firmware Development

Package

USER’S GUIDE

SW-EK-LM4F232-UG-2.1.4.178

Texas Instruments Incorporated

Copyright © 2011-2017 Texas Instruments Incorporated. All rights reserved. Tiva and TivaWare are trademarks of Texas Instruments Instruments. ARM and Thumb are registered trademarks and Cortex is a trademark of ARM Limited. Other names and brands may be claimed as the property of others.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semicon-

ductor products and disclaimers thereto appears at the end of this document.

Texas Instruments 108 Wild Basin, Suite 350 Austin, TX 78746

www.ti.com/tiva- c

Revision Information

This is version 2.1.4.178 of this document, last updated on February 22, 2017.

2 February 22, 2017

Table of Contents

Revision Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Example Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Bit-Banding (bitband) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Blinky (blinky) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.3 Boot Loader Demo 1 (boot_demo1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.4 Boot Loader Demo 2 (boot_demo2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.5 Boot Loader (boot_serial) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.6 USB Boot Loader (boot_usb) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.7 Hello World (hello) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.8 Hibernate Example (hibernate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.9 Interrupts (interrupts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.10 MPU (mpu_fault) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.11 Data Logger (qs-logger) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.12 SD card using FAT ﬁle system (sd_card) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.13 Sine Demo (sine_demo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.14 SoftUART Echo (softuart_echo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.15 Timer (timers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.16 UART Echo (uart_echo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.17 uDMA (udma_demo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.18 USB Generic Bulk Device (usb_dev_bulk) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.19 USB HID Keyboard Device (usb_dev_keyboard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.20 USB MSC Device (usb_dev_msc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.21 USB Serial Device (usb_dev_serial) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.22 USB host audio example application using SD Card FAT ﬁle system (usb_host_audio) . . . . . . . . 14

2.23 USB HID Keyboard Host (usb_host_keyboard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.24 USB HID Mouse Host (usb_host_mouse) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.25 USB Mass Storage Class Host Example (usb_host_msc) . . . . . . . . . . . . . . . . . . . . . . . . 14

2.26 USB Stick Update Demo (usb_stick_demo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.27 USB Memory Stick Updater (usb_stick_update) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.28 Watchdog (watchdog) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3 Buttons Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.2 API Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.3 Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4 Display Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.2 API Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.3 Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

IMPORTANT NOTICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

February 22, 2017 3

Table of Contents

4 February 22, 2017

1 Introduction

The Texas Instruments® Stellaris® EK-LM4F232 evaluation board is a platform that can be used for software development and prototyping a hardware design. It can also be used as a guide for custom board design using a Stellaris microcontroller.

The EK-LM4F232 includes a Stellaris ARM® Cortex™-M3-based microcontroller and the following features:

Stellaris® LM4F232H5QD microcontroller

Four 20V analog inputs

3-axis analog accelerometer

On-board temperature sensor

Bright 96 x 64 16-bit color OLED display

5 user buttons

User LED

Shunt for microcontroller current consumption measurement

MicroSD card connector

USB OTG connector

On-board In-Circuit Debug Interface (ICDI)

Coin cell backup battery for Hibernate feature

Power supply option from USB ICDI connection, or OTG connection

Introduction

This document describes the board-speciﬁc drivers and example applications that are provided for this development board.

February 22, 2017 5

Introduction

6 February 22, 2017

2 Example Applications

The example applications show how to utilize features of the EK-LM4F232 evaluation board. Examples are included to show how to use many of the general features of the Stellaris microcontroller, as well as the feature that are unique to this evaluation board.

A number of drivers are provided to make it easier to use the features of the EK-LM4F232. These drivers also contain low-level code that make use of the Stellaris peripheral driver library and utilities.

There is an IAR workspace ﬁle (ek-lm4f232.eww) that contains the peripheral driver library project, along with all of the board example projects, in a single, easy-to-use workspace for use with Embedded Workbench version 5.

There is a Keil multi-project workspace ﬁle (ek-lm4f232.uvmpw) that contains the peripheral driver library project, along with all of the board example projects, in a single, easy-to-use workspace for use with uVision.

All of these examples reside in the examples/boards/ek-lm4f232 subdirectory of the ﬁrmware development package source distribution.

2.1 Bit-Banding (bitband)

Example Applications

This example application demonstrates the use of the bit-banding capabilities of the Cortex-M3 microprocessor. All of SRAM and all of the peripherals reside within bit-band regions, meaning that bit-banding operations can be applied to any of them. In this example, a variable in SRAM is set to a particular value one bit at a time using bit-banding operations (it would be more efﬁcient to do a single non-bit-banded write; this simply demonstrates the operation of bit-banding).

2.2 Blinky (blinky)

A very simple example that blinks the on-board LED.

2.3 Boot Loader Demo 1 (boot_demo1)

An example to demonstrate the use of a ﬂash-based boot loader. At startup, the application will conﬁgure the UART and USB peripherals, and then branch to the boot loader to await the start of an update. If using the serial boot loader (boot_serial), the UART will always be conﬁgured at 115,200 baud and does not require the use of auto-bauding.

This application is intended for use with any of the three ﬂash-based boot loader ﬂavors (boot_serial or boot_usb) included in the software release. To accommodate the largest of these (boot_usb), the link address is set to 0x2800. If you are using serial, you may change this address to a 1KB boundary higher than the last address occupied by the boot loader binary as long as you also rebuild the boot loader itself after modifying its bl_conﬁg.h ﬁle to set APP_START_ADDRESS to the same value.

February 22, 2017 7

Example Applications

The boot_demo2 application can be used along with this application to easily demonstrate that the boot loader is actually updating the on-chip ﬂash.

Note that the LM4F232 and other Blizzard-class devices also support the serial and USB boot loaders in ROM. To make use of this function, link your application to run at address 0x0000 in ﬂash and enter the bootloader using the ROM_UpdateSerial and ROM_UpdateUSB functions (deﬁned in rom.h). This mechanism is used in the utils/swupdate.c module when built speciﬁcally targeting a suitable Blizzard-class device.

2.4 Boot Loader Demo 2 (boot_demo2)

An example to demonstrate the use of a ﬂash-based boot loader. At startup, the application will conﬁgure the UART, USB and Ethernet peripherals, wait for a widget on the screen to be pressed, and then branch to the boot loader to await the start of an update. If using the serial boot loader (boot_serial), the UART will always be conﬁgured at 115,200 baud and does not require the use of auto-bauding.

This application is intended for use with any of the three ﬂash-based boot loader ﬂavors (boot_eth, boot_serial or boot_usb) included in the software release. To accommodate the largest of these (boot_usb), the link address is set to 0x2800. If you are using serial or Ethernet boot loader, you may change this address to a 1KB boundary higher than the last address occupied by the boot loader binary as long as you also rebuild the boot loader itself after modifying its bl_conﬁg.h ﬁle to set APP_START_ADDRESS to the same value.

The boot_demo1 application can be used along with this application to easily demonstrate that the boot loader is actually updating the on-chip ﬂash.

Note that the LM4F232 and other Blizzard-class devices also the support serial and USB boot loaders in ROM. To make use of this function, link your application to run at address 0x0000 in ﬂash and enter the bootloader using either the ROM_UpdateUSB or ROM_UpdateSerial functions (deﬁned in rom.h). This mechanism is used in the utils/swupdate.c module when built speciﬁcally targeting a suitable Blizzard-class device.

2.5 Boot Loader (boot_serial)

The boot loader is a small piece of code that can be programmed at the beginning of ﬂash to act as an application loader as well as an update mechanism for an application running on a Tiva C Series microcontroller, utilizing either UART0, I2C0, SSI0, or USB. The capabilities of the boot loader are conﬁgured via the bl_conﬁg.h include ﬁle. For this example, the boot loader uses UART0 to load an application.

The conﬁguration is set to boot applications which are linked to run from address 0x2800 in ﬂash. This is higher than strictly necessary but is intended to allow the example boot loader-aware applications provided in the release to be used with any of the three boot loader example conﬁgurations supplied (serial or USB) without having to adjust their link addresses.

Note that the LM4F232 and other Blizzard-class devices also support serial boot loaders in ROM.

8 February 22, 2017

2.6 USB Boot Loader (boot_usb)

Applications intended for use with this version of the boot loader should be linked to run from address 0x2800 in ﬂash (rather than the default run address of 0). This address is chosen to ensure that boot loader images built with all supported compilers may be used without modifying the application start address. Depending upon the compiler and optimization level you are using, however, you may ﬁnd that you can reclaim some space by lowering this address and rebuilding both the application and boot loader. To do this, modify the makeﬁle or project you use to build the application to show the new run address and also change the APP_START_ADDRESS value deﬁned in bl_conﬁg.h before rebuilding the boot loader.

The USB boot loader may be demonstrated using the boot_demo1 and boot_demo2 example applications in addition to the boot_usb boot loader binary itself. Note that these are the only two example applications currently conﬁgured to run alongside the USB boot loader but making any of the other applications boot loader compatible is simply a matter of relinking them with the new start address and adding a mechanism to transfer control to the boot loader when required.

Example Applications

The Windows device driver required to communicate with the USB boot loader can be found on the software and documentation CD from the development kit package. It can also be found in the Windows driver package which can be downloaded via a link from http://www.ti.com/tiva.

A Windows command-line application, dfuprog, is also provided which illustrates how to perform uploads and downloads via the USB DFU protocol. The source for this application can be found in the /ti/TivaWare_C_Series-x.x/tools directory and the prebuilt executable is available in the package “TivaWare for C Series PC Companion Utilities” available for download via a link from http://www.ti.com/tivaware .

2.7 Hello World (hello)

A very simple “hello world” example. It simply displays “Hello World!” on the display and is a starting point for more complicated applications. This example uses calls to the TivaWare Graphics Library graphics primitives functions to update the display. For a similar example using widgets, please see “hello_widget”.

2.8 Hibernate Example (hibernate)

An example to demonstrate the use of the Hibernation module. The user can put the microcontroller in hibernation by pressing the select button. The microcontroller will then wake on its own after 5 seconds, or immediately if the user presses the select button again. The program keeps a count of the number of times it has entered hibernation. The value of the counter is stored in the battery backed memory of the Hibernation module so that it can be retrieved when the microcontroller wakes.

February 22, 2017 9

Example Applications

2.9 Interrupts (interrupts)

This example application demonstrates the interrupt preemption and tail-chaining capabilities of Cortex-M4 microprocessor and NVIC. Nested interrupts are synthesized when the interrupts have the same priority, increasing priorities, and decreasing priorities. With increasing priorities, preemption will occur; in the other two cases tail-chaining will occur. The currently pending interrupts and the currently executing interrupt will be displayed on the display; GPIO pins D0, D1 and D2 will be asserted upon interrupt handler entry and de-asserted before interrupt handler exit so that the off-to-on time can be observed with a scope or logic analyzer to see the speed of tail-chaining (for the two cases where tail-chaining is occurring).

2.10 MPU (mpu_fault)

This example application demonstrates the use of the MPU to protect a region of memory from access, and to generate a memory management fault when there is an access violation.

2.11 Data Logger (qs-logger)

This example application is a data logger. It can be conﬁgured to collect data from up to 10 data sources. The possible data sources are:

4 analog inputs, 0-20V

3-axis accelerometer

internal and external temperature sensors

processor current consumption

The data logger provides a menu navigation that is operated by the buttons on the EK-LM4F232 board (up, down, left, right, select). The data logger can be conﬁgured by using the menus. The following items can be conﬁgured:

data sources to be logged

sample rate

storage location

sleep modes

clock

Using the data logger:

Use the CONFIG menu to conﬁgure the data logger. The following choices are provided:

CHANNELS - enable speciﬁc channels of data that will be logged

PERIOD - select the sample period

STORAGE - select where the collected data will be stored:

• FLASH - stored in the internal ﬂash memory

• USB - stored on a connected USB memory stick

10 February 22, 2017

Example Applications

• HOST PC - transmitted to a host PC via USB OTG virtual serial port

• NONE - the data will only be displayed and not stored

SLEEP - select whether or not the board sleeps between samples. Sleep mode is allowed when storing to ﬂash at with a period of 1 second or longer.

CLOCK - allows setting of internal time-of-day clock that is used for time stamping of the sampled data

Use the START menu to start the data logger running. It will begin collecting and storing the data. It will continue to collect data until stopped by pressing the left button or select button.

While the data logger is collecting data and it is not conﬁgured to sleep, a simple strip chart showing the collected data will appear on the display. If the data logger is conﬁgured to sleep, then no strip chart will be shown.

If the data logger is storing to internal ﬂash memory, it will overwrite the oldest data. If storing to a USB memory device it will store data until the device is full.

The VIEW menu allows viewing the values of the data sources in numerical format. When viewed this way the data is not stored.

The SAVE menu allows saving data that was stored in internal ﬂash memory to a USB stick. The data will be saved in a text ﬁle in CSV format.

The ERASE menu is used to erase the internal memory so more data can be saved.

When the EK-LM4F232 board running qs-logger is connected to a host PC via the USB OTG connection for the ﬁrst time, Windows will prompt for a device driver for the board. This can be found in /ti/TivaWare_C_Series-x.x/windows_drivers assuming you installed the software in the default folder.

A companion Windows application, logger, can be found in the /ti/TivaWare_C_Series-x.x/tools/bin directory. When the data logger’s STORAGE option is set to "HOST PC" and the board is connected to a PC via the USB OTG connection, captured data will be transfered back to the PC using the virtual serial port that the EK board offers. When the logger application is run, it will search for the ﬁrst connected EK-LM4F232 board and display any sample data received. The application also offers the option to log the data to a ﬁle on the PC.

2.12 SD card using FAT ﬁle system (sd_card)

This example application demonstrates reading a ﬁle system from an SD card. It makes use of FatFs, a FAT ﬁle system driver. It provides a simple command console via a serial port for issuing commands to view and navigate the ﬁle system on the SD card.

The ﬁrst UART, which is connected to the USB debug virtual serial port on the evaluation board, is conﬁgured for 115,200 bits per second, and 8-N-1 mode. When the program is started a message will be printed to the terminal. Type “help” for command help.

For additional details about FatFs, see the following site:

http://elm-chan.org/fsw/ff/00index_e.html

February 22, 2017 11

Example Applications

2.13 Sine Demo (sine_demo)

This example uses the ﬂoating point capabilities of the Tiva C Series processor to compute a sine wave and show it on the display.

2.14 SoftUART Echo (softuart_echo)

This example application utilizes the SoftUART to echo text. The SoftUART is conﬁgured to use the same pins as the ﬁrst UART (connected to the FTDI virtual serial port on the evaluation board), at 115,200 baud, 8-n-1 mode. All characters received on the SoftUART are transmitted back to the SoftUART.

2.15 Timer (timers)

This example application demonstrates the use of the timers to generate periodic interrupts. One timer is set up to interrupt once per second and the other to interrupt twice per second; each interrupt handler will toggle its own indicator on the display.

2.16 UART Echo (uart_echo)

This example application utilizes the UART to echo text. The ﬁrst UART (connected to the USB debug virtual serial port on the evaluation board) will be conﬁgured in 115,200 baud, 8-n-1 mode. All characters received on the UART are transmitted back to the UART.

2.17 uDMA (udma_demo)

This example application demonstrates the use of the uDMA controller to transfer data between memory buffers, and to transfer data to and from a UART. The test runs for 10 seconds before exiting.

2.18 USB Generic Bulk Device (usb_dev_bulk)

This example provides a generic USB device offering simple bulk data transfer to and from the host. The device uses a vendor-speciﬁc class ID and supports a single bulk IN endpoint and a single bulk OUT endpoint. Data received from the host is assumed to be ASCII text and it is echoed back with the case of all alphabetic characters swapped.

A Windows INF ﬁle for the device is provided on the installation CD and in the C:/ti/TivaWare_C_Series-x.x/windows_drivers directory of TivaWare releases. This INF contains information required to install the WinUSB subsystem on WindowsXP and Vista PCs. WinUSB is a

12 February 22, 2017

Example Applications

Windows subsystem allowing user mode applications to access the USB device without the need for a vendor-speciﬁc kernel mode driver.

A sample Windows command-line application, usb_bulk_example, illustrating how to connect to and communicate with the bulk device is also provided. The application binary is installed as part of the “TivaWare for C Series PC Companion Utilities” package (SW-TM4C-USB-WIN) on the installation CD or via download from http://www.ti.com/tivaware . Project ﬁles are included to allow the examples to be built using Microsoft Visual Studio 2008. Source code for this application can be found in directory ti/TivaWare_C_Series-x.x/tools/usb_bulk_example.

2.19 USB HID Keyboard Device (usb_dev_keyboard)

This example application turns the evaluation board into a USB keyboard supporting the Human Interface Device class. When the push button is pressed, a sequence of key presses is simulated to type a string. Care should be taken to ensure that the active window can safely receive the text; enter is not pressed at any point so no actions are attempted by the host if a terminal window is used (for example). The status LED is used to indicate the current Caps Lock state and is updated in response to any other keyboard attached to the same USB host system.

The device implemented by this application also supports USB remote wakeup allowing it to request the host to reactivate a suspended bus. If the bus is suspended (as indicated on the application display), pressing the push button will request a remote wakeup assuming the host has not speciﬁcally disabled such requests.

2.20 USB MSC Device (usb_dev_msc)

This example application turns the evaluation board into a USB mass storage class device. The application will use the microSD card for the storage media for the mass storage device. The screen will display the current action occurring on the device ranging from disconnected, no media, reading, writing and idle.

2.21 USB Serial Device (usb_dev_serial)

This example application turns the evaluation kit into a virtual serial port when connected to the USB host system. The application supports the USB Communication Device Class, Abstract Control Model to redirect UART0 trafﬁc to and from the USB host system.

Assuming you installed TivaWare in the default directory, a driver information (INF) ﬁle for use with Windows XP, Windows Vista and Windows7 can be found in C:/ti/TivaWare_C_Seriesx.x/windows_drivers. For Windows 2000, the required INF ﬁle is in C:/ti/TivaWare_C_Seriesx.x/windows_drivers/win2K.

February 22, 2017 13

Example Applications

2.22 USB host audio example application using SD Card FAT ﬁle system (usb_host_audio)

This example application demonstrates playing .wav ﬁles from an SD card that is formatted with a FAT ﬁle system using USB host audio class. The application will only look in the root directory of the SD card and display all ﬁles that are found. Files can be selected to show their format and then played if the application determines that they are a valid .wav ﬁle. Only PCM format (uncompressed) ﬁles may be played.

For additional details about FatFs, see the following site:

http://elm-chan.org/fsw/ff/00index_e.html

2.23 USB HID Keyboard Host (usb_host_keyboard)

This example application demonstrates how to support a USB keyboard attached to the evaluation kit board. The display will show if a keyboard is currently connected and the current state of the Caps Lock key on the keyboard that is connected on the bottom status area of the screen. Pressing any keys on the keyboard will cause them to be printed on the screen and to be sent out the UART at 115200 baud with no parity, 8 bits and 1 stop bit. Any keyboard that supports the USB HID BIOS protocol should work with this demo application.

2.24 USB HID Mouse Host (usb_host_mouse)

This application demonstrates the handling of a USB mouse attached to the evaluation kit. Once attached, the position of the mouse pointer and the state of the mouse buttons are output to the display.

2.25 USB Mass Storage Class Host Example (usb_host_msc)

This example application demonstrates reading a ﬁle system from a USB ﬂash disk. It makes use of FatFs, a FAT ﬁle system driver. It provides a simple widget-based display for showing and navigating the ﬁle system on a USB stick.

For additional details about FatFs, see the following site:

http://elm-chan.org/fsw/ff/00index_e.html

2.26 USB Stick Update Demo (usb_stick_demo)

An example to demonstrate the use of the ﬂash-based USB stick update program. This example is meant to be loaded into ﬂash memory from a USB memory stick, using the USB stick update program (usb_stick_update), running on the microcontroller.

14 February 22, 2017

Example Applications

After this program is built, the binary ﬁle (usb_stick_demo.bin), should be renamed to the ﬁlename expected by usb_stick_update ("FIRMWARE.BIN" by default) and copied to the root directory of a USB memory stick. Then, when the memory stick is plugged into the eval board that is running the usb_stick_update program, this example program will be loaded into ﬂash and then run on the microcontroller.

This program simply displays a message on the screen and prompts the user to press the select button. Once the button is pressed, control is passed back to the usb_stick_update program which is still is ﬂash, and it will attempt to load another program from the memory stick. This shows how a user application can force a new ﬁrmware update from the memory stick.

2.27 USB Memory Stick Updater (usb_stick_update)

This example application behaves the same way as a boot loader. It resides at the beginning of ﬂash, and will read a binary ﬁle from a USB memory stick and program it into another location in ﬂash. Once the user application has been programmed into ﬂash, this program will always start the user application until requested to load a new application.

When this application starts, if there is a user application already in ﬂash (at APP_START_ADDRESS), then it will just run the user application. It will attempt to load a new application from a USB memory stick under the following conditions:

no user application is present at APP_START_ADDRESS

the user application has requested an update by transferring control to the updater

the user holds down the eval board push button when the board is reset

When this application is attempting to perform an update, it will wait forever for a USB memory stick to be plugged in. Once a USB memory stick is found, it will search the root directory for a speciﬁc ﬁle name, which is FIRMWARE.BIN by default. This ﬁle must be a binary image of the program you want to load (the .bin ﬁle), linked to run from the correct address, at APP_START_ADDRESS.

The USB memory stick must be formatted as a FAT16 or FAT32 ﬁle system (the normal case), and the binary ﬁle must be located in the root directory. Other ﬁles can exist on the memory stick but they will be ignored.

2.28 Watchdog (watchdog)

This example application demonstrates the use of the watchdog as a simple heartbeat for the system. If the watchdog is not periodically fed, it will reset the system. Each time the watchdog is fed, the LED is inverted so that it is easy to see that it is being fed, which occurs once every second. To stop the watchdog being fed and, hence, cause a system reset, press the select button.

February 22, 2017 15

Example Applications

16 February 22, 2017

3 Buttons Driver

Introduction . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . 17

API Functions . . .. . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . 17

Programming Example . . .. . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . 18

3.1 Introduction

The buttons driver provides functions to make it easy to use the push buttons on the EK-LM4F232 evaluation board. The driver provides a function to initialize all the hardware required for the buttons, and features for debouncing and querying the button state.

This driver is located in examples/boards/ek-lm4f232/drivers, with buttons.c containing the source code and buttons.h containing the API declarations for use by applications.

3.2 API Functions

Buttons Driver

Functions

void ButtonsInit (void) uint8_t ButtonsPoll (uint8_t ∗pui8Delta, uint8_t ∗pui8RawState)

3.2.1 Function Documentation

3.2.1.1 ButtonsInit

Initializes the GPIO pins used by the board pushbuttons.

Prototype:

void ButtonsInit(void)

Description:

This function must be called during application initialization to conﬁgure the GPIO pins to which the pushbuttons are attached. It enables the port used by the buttons and conﬁgures each button GPIO as an input with a weak pull-up.

Returns:

None.

3.2.1.2 ButtonsPoll

Polls the current state of the buttons and determines which have changed.

February 22, 2017 17

Buttons Driver

Prototype:

uint8_t ButtonsPoll(uint8_t*pui8Delta,

uint8_t*pui8RawState)

Parameters:

pui8Delta points to a character that will be written to indicate which button states changed

since the last time this function was called. This value is derived from the debounced state of the buttons.

pui8RawState points to a location where the raw button state will be stored.

Description:

This function should be called periodically by the application to poll the pushbuttons. It determines both the current debounced state of the buttons and also which buttons have changed state since the last time the function was called.

In order for button debouncing to work properly, this function should be caled at a regular interval, even if the state of the buttons is not needed that often.

If button debouncing is not required, the the caller can pass a pointer for the pui8RawState parameter in order to get the raw state of the buttons. The value returned in pui8RawState will be a bit mask where a 1 indicates the buttons is pressed.

Returns:

Returns the current debounced state of the buttons where a 1 in the button ID’s position indicates that the button is pressed and a 0 indicates that it is released.

3.3 Programming Example

The following example shows how to use the buttons driver to initialize the buttons, debounce and read the buttons state.

// // Initialize the buttons. // ButtonsInit();

// // From timed processing loop (for example every 10 ms) // ... {

// // Poll the buttons. When called periodically this function will // run the button debouncing algorithm. // ucState = ButtonsPoll(&ucDelta, 0);

// // Test to see if the SELECT button was pressed and do something // if(BUTTON_PRESSED(SELECT_BUTTON, ucState, ucDelta)) {

... // SELECT button action

}

18 February 22, 2017

4 Display Driver

Introduction . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . 19

API Functions . . .. . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . 19

Programming Example . . .. . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . .. . . . .. . . .. . .. . . . .. . . . . . .. . . . . . .. . . . . . 20

4.1 Introduction

The display driver offers a standard interface to access display functions on the CrystalFontz 96x64 16-bit color OLED display and is used by the Stellaris Graphics Library and widget manager. In addition to providing the tDisplay structure required by the graphics library, the display driver also provides an API for initializing the display.

This driver is located in examples/boards/ek-lm4f232/drivers, with cfal96x64x16.c containing the source code and cfal96x64x16.h containing the API declarations for use by applications.

4.2 API Functions

Display Driver

Functions

void CFAL96x64x16Init (void)

Variables

const tDisplay g_sCFAL96x64x16

4.2.1 Function Documentation

4.2.1.1 CFAL96x64x16Init

Initializes the display driver.

Prototype:

void CFAL96x64x16Init(void)

Description:

This function initializes the SSD1332 display controller on the panel, preparing it to display data.

Returns:

None.

February 22, 2017 19

Display Driver

4.2.2 Variable Documentation

4.2.2.1 g_sCFAL96x64x16

Deﬁnition:

const tDisplay g_sCFAL96x64x16

Description:

The display structure that describes the driver for the Crystalfontz CFAL9664-F-B1 OLED panel with SSD 1332 controller.

4.3 Programming Example

The following example shows how to initialize the display and prepare to draw on it using the graphics library.

tContext sContext;

// // Initialize the display. // CFAL96x64x16Init();

// // Initialize a graphics library drawing context. // GrContextInit(&sContext, &g_sCFAL96x64x16);

20 February 22, 2017

February 22, 2017 21

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.

TI warrants performance of its components to the speciﬁcations applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed.

TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide adequate design and operating safeguards.

TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI.

Reproduction of signiﬁcant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions.

Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.

Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications.

In some cases, TI components may be promoted speciﬁcally to facilitate safety-related applications. With such components, TI’s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. Nonetheless, such components are subject to these terms.

No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized ofﬁcers of the parties have executed a special agreement speciﬁcally governing such use.

Only those TI components which TI has speciﬁcally designated as military grade or “enhanced plastic” are designed and intended for use in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components which have not been so designated is solely at the Buyer’s risk, and that Buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use.

TI has speciﬁcally designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.

Products Applications

Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Ampliﬁers ampliﬁer.ti.com Communications and Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energy and Lighting www.ti.com/energy Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rﬁd.com OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com Wireless Connectivity www.ti.com/wirelessconnectivity

Mailing Address: Texas Instruments, Post Ofﬁce Box 655303, Dallas, Texas 75265

22 February 22, 2017

Texas Instruments EK-LM4F232 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual