I'd like to make a multi-room intercom for my house that can be used from my Android phone, or from the intercom stations. I've been trying to accomplish this with a PIC32 with a mic connected to an ADC pin, and PWM output to a speaker (with a r/c low-pass filter), and an ESP8266 to send/receive over wifi.
My first step was to try to make the PIC32 read from the ADC and immediately write it out with PWM. But this seems to give me really poor quality audio. I'm not sure if that is from the PIC32's 10-bit ADC, or from the PWM, or something else (mic/speaker quality?). The audio is also way too quiet, but I should be able to solve that with an audio amplifier (maybe an LM386?).
Anyway, I feel like I'm in way over my head with audio input/output. Maybe PIC is the wrong platform. Does anyone have any recommendations on a better microcontroller or peripherals for audio in/out?
Maybe it would be better to do a simple FM-based intercom, and have a raspberry-pi with a receiver that can be the bridge between android and the intercom? I'd be a little worried about privacy with a simple FM transmitter/receiver solution...
My overall goal is for it to be as cheap as possible (so I can afford to make several units for several rooms), and for it to be small enough to fit into a 1-gang electrical box so it can take the place of a light switch (and hopefully I can find a nice small light switch or relay to cram in there with it).
I'm still tinkering with my PIC32+ESP8266 approach, but I'm hoping someone smarter than me can point me in a better direction.
My first step was to try to make the PIC32 read from the ADC and immediately write it out with PWM. But this seems to give me really poor quality audio. I'm not sure if that is from the PIC32's 10-bit ADC, or from the PWM, or something else (mic/speaker quality?). The audio is also way too quiet, but I should be able to solve that with an audio amplifier (maybe an LM386?).
Anyway, I feel like I'm in way over my head with audio input/output. Maybe PIC is the wrong platform. Does anyone have any recommendations on a better microcontroller or peripherals for audio in/out?
Maybe it would be better to do a simple FM-based intercom, and have a raspberry-pi with a receiver that can be the bridge between android and the intercom? I'd be a little worried about privacy with a simple FM transmitter/receiver solution...
My overall goal is for it to be as cheap as possible (so I can afford to make several units for several rooms), and for it to be small enough to fit into a 1-gang electrical box so it can take the place of a light switch (and hopefully I can find a nice small light switch or relay to cram in there with it).
I'm still tinkering with my PIC32+ESP8266 approach, but I'm hoping someone smarter than me can point me in a better direction.