Contents of this directory
This directory contains the following items:
- pressanykey: The pressanykey runtime for the LPC1343 / Anykey0x.de board, linker script and makefile
- checksum: A tool to calculate and adjust the checksum of a firmware file
- several example projects (see below for descriptions)
In contrast to other runtimes, pressanykey does not link against precompiled libraries. Instead, the runtime is included into projects as source code. The projects compile in a few seconds and linking is static anyway, so there's no need for precompiled libraries. You always have the full source at your fingertips - less magic, more control.
The makefile is designed to compile and link all .c files in your project directory and subirectories, so there's no need to modify it for new source files. Just make sure you don't have unused .c files in your project directory.
We're currently building up the firmware utilities, so not all peripherals are working yet.
Setup build environment
- Install gcc arm-none-eabi toolchain (see below)
- Go to checksum directory, build checksum tool (
- Move checksum tool or adjust $PATH so that it can be found
Alternatively, the examples can be built with clang/llvm (experimental - more info coming).
Setting up a project
Either copy an existing example directory (using cp -R) or do the following steps to create a project directory from scratch:
- create a project directory
- create a main.c file (the name doesn't actually matter)
- to use pressanykey firmware library, #include "pressanykey/pressanykey.h"
- link, symlink or copy pressanykey directory to project directory
- link, symlink or copy makefile (inside pressanykey dir) to project directory
- link, symlink or copy lpc1343.ld (inside pressanykey dir) to project directory
make(will compile and link all c files in project dir and subdirs)
- connect target board in USB programming mode
make mac-install(optionally copy the resulting .bin file manually)
- disconnect and re-plug target board
In most cases, symlinking (or hard-linking, if you prefer) the pressanykey directory, makefile and linker script from your project directory to the pressanykey directory is recommended. This way, the project refers to the original, unaltered runtime library.
The build system should work in OSX without modifications. For other *NIX platforms, please adjust the target board path and unmount command for the makefile ("mac-install" target).
Linux' FAT drivers apparently interfere with copying, you need to transfer the files directly onto the device:
dd if=firmware.bin of=/dev/<wherever the ANYKEY appears>
This kit contains some examples. Here's a short overview, from basic to advanced:
The embedded "Hello World": A blinking LED. Timing is done using busy wait. One of the simplest possible applications. Shows writing digital output pins.
The LED lights up when the button is pressed. Shows reading digital input from pins and configuring pullup/pulldown resistors for inputs.
A smoothly pulsing LED. The LED is dimmed and animated using PWM (pulse width modulation) in the systick timer. Shows how to use the systick timer.
Generates a VGA signal with eight vertical color bars. To use this example, a VGA connector and three resistors are required (schematics can be found in the main.c file). The example shows inline assembly.
Generates a VGA signal with text (800 x 600 @ 56Hz). To use this example, a VGA connector and three resistors are required (schematics identical to colorbars example). The example shows some advanced inline assembly strategies.
This example uses the software USB stack to implement a raw USB device. The device does not have any functionality other than the required standard USB functionality for USB enumeration.
Implements a simple USB HID keyboard. The example includes a two-step abstraction: hid.c implements a HID device based on the USB software stack. keyboard.c builds a keyboard on top of the HID device functionality. The keyboard can write text and the LED will act as a caps lock key (note that not all OSes synchronize caps lock among multiple keyboards). This example may be useful as a base for implementing your own HID devices.
A HID-keyboard implementation of Nerd Pursuit - see https://github.com/Nerds/NerdPursuit. Play it on a standard *NIX shell.
Installing the compiler
The most common open source compiler toolchain in use for ARM based systems is the gnu compiler toolchain. Mentor Graphics, formerly CodeSourcery, provide and maintain the ARM version of GCC.
Check your distributions package manager, it will probably contain a
package called something like
Alternatively, you can download an installer directly from CodeSourcery
You'll need to make the installer executable, using
chmod +x, and then
just run it.
HomeBrew have the ARM gcc compiler as packages:
$ sudo port install arm-none-eabi-gcc
$ brew install arm-none-eabi-gcc
We're currently looking into this.
You can find some helpful hints on how to install the toolchain at the r0cket website. We're currently putting together a VM that contains all necessary tools preinstalled.