Okay, I have just assembled the FM radio board. All appears to be working except no output. Here are the symptoms: RC5 on the micro is driven low by station 1 select button. If the button is pressed quickly and then released the level on the micro pin rises to about 3.3v. If the button is held down for > 1 second and then released the level on the micro pin first rises to around two volts and the steps slowly towards 3.3v over about 5 to 10 seconds.
The rest of the button signals appear to operate as you would expect, except nothing has any affect on the radio.
There is no activity on the volume control pin, GPIO3. And the I2C bus is doing continuous reads to address 21? which appears to return a huge string of data before the request is repeated.
Is there anything else I can look at?
Sorry I binned the unit. No technical information available on the radio chip.
This is a real shame as it was purchased for a bright young 11 year old to find out a bit about electronics. We got a crystal set to work, built from scratch and I purchased this item for him to build next.
Real shame it was a dead duck.
Geoffrey Frost
Electronics design engineer.