______          _ _
| ___ \        | (_)
| |_/ /__ _  __| |_ _   _ _ __   ___
|    // _` |/ _` | | | | | '_ \ / _ \
| |\ \ (_| | (_| | | |_| | | | | (_) |
\_| \_\__,_|\__,_|_|\__,_|_| |_|\___/

Radiuno

A bare-metal commandline server for the Arduino Uno + SparkFun si4735 shield, written virtually from scratch in C99. It was developed and tested on a genuine Arduino Uno, but the Uno is used as just another Atmel AVR board without all the Arduino sugarcoating. Flash this code to a Uno, open a serial port terminal (like minicom or putty) at 115200 baud 8N1, and get a commandline interface to the si4735.

Install

Requires avr-gcc and avr-libc. Being a bare-metal project, it doesn't require any Arduino stuff. You'll need to edit the Makefile to point to your avr cross-compilation environment. You might also need to change some other specifics, such as the default USB device, /dev/ttyACM0. Then:

# Build image and flash to device
make flash

Acknowledgements

The si4735 code was written with one eye on the datasheets and another on the original Trunet library. Having a working reference implementation proved indispensable for maintaining my sanity among such questions as "why am I not getting data" (answer: typos) and "why is the data that I'm getting corrupted" (answer: despite what the datasheet says, the chip can't handle SPI transfer speeds of over 500 KHz).