I'm working on a little side project with the LPC810 (Cortex M0+ 32 bit ARM MCU, 8 pin DIP package, 4kB flash, 1kB SRAM). I need a UI to convey to the user a temperature setting. I only have about 2 pins spare to implement the UI.... so using LEDs is going to a challenge.
I had an idea of using just one pin to drive a speaker or peizzo buzzer and convey the temperature in speech. Just the digits 0 - 9 in english is all I need. Storing 0-9 in PCM is out of the question with so little flash. So I was wondering is anyone aware of open source code that would allow for very high compression of a small dictionary of words what would be light enough on CPU/RAM to work with a Cortex M0 class MCU? (I have a strong hunch this is plain out of reach of low end Cortex M0 MCUs without external memory).