I am seeking a small microcontroller to act as a secondary board for a Teensy 3.1. I need four analog inputs with 12-bits ADC.
I don't know what's the best way to connect to the Teensy 3.1 : serial, I2C, SPI ?
I need something really small, such as an Adafruit Trinket (sadly the ATtiny85 has only 10-bits ADC).
Thank you in advance.
don't know a board but can tell a bot about the protocols
I2C supports multiple devices, so choosing I2C will not "harm". Drawback is that it is relative slow.
SPI is much faster, but you can only connect one device (every extra device needs an extra chip select)
If you have SPI free for your project that might be preferred.
Serial should be kept for debugging imho.
Thanks robtillaart. Any board to recommend?
How about a promini?
I also offer a '328P & '1284P board with extra power & gnd connections, but no voltage regulator if you have a 5V supply.
and am working up '2561 and '2560 boards.
(http://www.crossroadsfencing.com/BobuinoRev17/Mega2561 system board.jpg)
(http://www.crossroadsfencing.com/BobuinoRev17/Mega2560 system board.jpg)
Need to get some processors ordered!
OP needs 12-bit ADCs, which rules out the AVRs, provided you need actual 12-bit ADC, ie, oversampling per Atmel App note AVR121 http://www.atmel.com/images/doc8003.pdf is not sufficient.
My suggestion would be to either buy another Teensy, or (if it isn't too big) try the Maple Mini. It got great support (https://github.com/rogerclarkmelbourne/Arduino_STM32), and cost less than 4$ (http://www.ebay.com/itm//141404280807). The board got 34 IO pins and 9 12-bit analog inputs. It also got 3 serial ports, 2 i2c busses, and 2 SPI busses.
and it's REALLY fast compared to an Arduino UNO