Progress in adapting a small AM/FM radio for Arduino control. The internal MCU communicates with the AKC6951 chip via I2C. Here is documented the wiring of how to tap into this communication channel, and show the communication on an oscilloscope.
I will first be using an ATTiny85 because it can do I2C no problem. Down the road, I’m worried about VBATT, as the radio works fine with the batteries down to 2V, and probably a lot lower. If this test of sending commands worked on an ATTiny85, I can run the code on an MCU that is OK with lower voltage, or something like a Seeeduino Xiao SAMD21…
Next step is to write the code to command the radio. Still need to figure out the minimum number of controls for the MCU,, like buttons, knobs, displays, etc.
