I've been working with the ARMexpress microcontrollers, which has only digital I/O. Apart from the lack of A/D inputs, I love it. So I'm looking for some way to work around that limitation.
It seems to me that you could use a PIC or Atmel chip for this. These could be programmed to respond to a simple serial protocol, where the input indicates the pin number of interest, and the response is the A/D level on that pin. Is this a reasonable approach? Which specific chip would be a good choice for this?
Also, is there an off-the-shelf solution that does the same thing, without requiring an AVR/PIC programmer? Something set up to speak I2C,
1-Wire, SPI, or serial? (Any of those should be easy to talk to from the ARMexpress.)Thanks,
- Joe