We have just completed porting our (single source) firmware from a range of other ‘Arduino’ type platforms to Particle’s Photon, having received it yesterday & thought it would be useful sharing some of our experiences for other ‘newbies’. The photon is one of a breed of modern IoT devices hitting the market at relatively low cost. It features a STM32F205 120Mhz ARM Cortex M3 processor running at 120MHz with 1MB flash, 128KB RAM and the all important WiFi. We have been wanting to support the previous Spark Core ($39), but couldn’t resist this little device at the low price point. Particle are also offering a similar embedded device in larger quantities of 10+, for $12, including FCC certification.
In Part 1 of this series, we demonstrated how to send signals using simple Infrared PWM on Arduino. In this Part 2 post we look at sending RAW IR signals – specifically a RAW NEC signal and a longer RAW Mitsubishi Air Conditioner signal. We have also improved the method shown in Part 1 due to some issues we identified when sending ‘real’ signals versus the ‘test’ signal we used before. (More on that later). In Part 3, we will take the signals from this post and show how to send them using their binary (or Hex) representation, which saves lots of SRAM.