I’m trying to develop a simple “hello world” application to familiarise myself with FreeRTOS. This is part of a final-year university electrical engineering project. The development environment:
o IAR Embedded Workbench v5.11 for ARM (Kickstart edition) on Windows 2000 Pro
o FreeRTOS 5.0.0
o ATMEL AT91SAM7S-EK development board
Looking at the Demo ports, I’ve managed to get the IAR example for the AT91SAM7S64 working… building and clicking the Go button yields an immediate “New Hardware Found” dialogue, stating it has found a “FreeRTOS.org Joystick”, and the LEDs on the board start flashing furiously. So I know the board works, and that FreeRTOS executes on it.
What I can’t seem to put my finger on, is either:
(1) Documentation on how to interface with the UART on the board
(2) Example code that interfaces with the on-board UART
Ultimately I’ll be switching to using an AT91SAM7X board – the project is to investigate controller area networks. As part of this project, I’d like to use RS-232 to act as a human-machine interface.
The demos seem to include a comtest.c example that would appear to do this – it is included in the AT91SAM7S64 IAR example, but the code doesn’t appear to have a visible effect on the serial port. I’ve got the UART port hooked up to one of my desktop’s serial ports via a null-modem cable, with HyperTerminal configured at 115200 baud, 8n1, no flow control.
Has anyone seen any well-documented examples on how to drive the serial ports on these things, or know of some documentation describing how to go about it? I’ve looked at the PDFs supplied on the DVD that came with the board, as well as the documentation on ATMEL’s site. If anyone has any tips on how to go about this, I’d be very interested. If I have to write one from scratch, I’m also happy to make a bare bones version that can be included in the FreeRTOS distribution.