I’m thinking of buying a couple high-power micro metal gear motors with carbon brushes and extended motor shafts found at https://www.pololu.com/category/141/micro-metal-gearmotors-with-extended-motor-shafts. I want to add encoders to the motors. https://www.pololu.com/product/3081 However, considering the RPM of a motor, the gear ratio, and the encoder’s counts per revolution how can I be sure counts from the encoder won’t be lost? What if I buy a 320 RPM motor with a 100:1 gear ratio? Will an Arduino Uno or Raspberry Pi 2 be able to read the signals fast enough and keep count or will I need to buy/build more specialized hardware to correctly count the signals from the encoders?
An Arduino Uno should be able to read the signals from those encoders with the motors if you use interrupts. You might find the Arduino “Reading Rotary Encoders” tutorial helpful. I do not know of a good resource for reading quadrature encoders with a Raspberry Pi, and I suspect it might be difficult to do since it does not have a real-time operating system. If you want to use a Raspberry Pi in your system, you might consider one of our A-Star 32U4 Robot Controllers, which are Arduino-compatible and designed to mount on top of the Raspberry Pi, for handling the encoders.