Sparkfun Si4703 FM Radio

tdlivings

Inspired by theParallax Quick Start FM Radio module and demo I decided to try the SparkfunSi4703 FM Radio module which has the added feature of decoding the RDS signals.This is a project in the spirit of build a kludge and learn from it and is ongoing.

The Si4703 issimilar to the Parallax FM radio but not the same pin out or register set.



I did not use theQuick Start key pads but instead decoded the output of my Sony IR remotecontrol.
The code has hard coded IR codes for my Sony Remote Control.
The spin file IRSonyis my decoding object which was inspired by forum posts and online info onusing the Propeller counters to decode IR signals. I repeated the concept as anexercise.

I wanted to tiemultiple I2C devices to pin 28,29 of QuickStart just as anexercise.
Because both the QuickStart board and the Sparkfun Si4703 both have I2C pullups I end up with a lower value of pull up resistors but not a value that wouldbe a problem.

I modified MiniI2C.spin that is supplied byParallax for their FM Radio Demo to letgo of the I2C pins because there are multiple I2C devices to pins 28, 29, the Quick Start EEProm and the Si4703 FMRadio.

If the Prop pin's Iselected look funny it is because I chose pins that did not interfere with theGadget Gangster Touch screen, which I plan on trying as a radio display.

Propeller Multicoreand waitpeq and waitpne instructions make implementing watching for andprocessing RDS messages much easier than using interrupts. I am using a cog towatch for the Si4703 to signal RDS data has been decoded by setting GPIO2 low.

For this version Iam only decoding RDS Group messages I amreceiving to see if I can decode anything and to study what it looks like . Iam not sure I am doing what is intended with the Group 2A message. I am decodingthe text string fine but the A/B bit has been referred to as a clear screen bitand I am not doing that at this time. An experiment to try.

Because of the factthat the RDS signal is at the lowest modulation reception can bepoor.
Because of this you need to see the same thing twice to put it out on thedisplay.
I could have also only changed what is displayed after it appears twice if Iget something else twice.
My 2004 ChevyTrailblazer radio only displays the group $0A eight character strings.



This is an on goingproject with the radio chip as a mule to try different coding techniques anduser interface idea's.

Tom