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PI Face Digital 2 with real PWM

balearicdynamics

It's just an idea and before trying to make tests i'd like to ask your vision.

 

The power of the PI Face Digital is that there are a certain number of elements, including a couple of good quality relays, ready to use. Then there is a missing component (as for what I think maybe really useful) that is a way to support PWM. As a matter of fact there is a soft PWM library in the specific Wire library but frankly I don't trust so much to trash 10% or more of the CPU to manage servos and PWM motors. Not only but the program should run to be sure that the PWM signal is kept at the desired frequency.

 

Based on these premises it is almost cheap and simple to make up to 6 PWM with a small board to connect to the PI Face Digital, consuming only 2 PINs of the board outputs. The point is that to control the PWM small circuit it is needed an I2C signal so my question is the following:

 

As it is possible to put more than one PI Face boards on a small bus, changing the PI Face board number last two bits (that is, the chip address signal of the I2C bus), why not to use one of the available bus connectors (that are well documented) to manage something different with the I2C protocol? Does is sounds correct ?

  • 0

    Just my two cents worth alert. The Pi best feature was the arm is a powerful Linux computer with some real time interfacing available. But it does lake lack any DAC/ADC interfaces as well as PWM like on the Arduino. Arduino processor although not powerful to run Linux is a great real time environment. The only only ones to marry the two are the PCdruino V3 nano at a very reasonable cost.

    Clem

  • 0 in reply to clem57

    You say correct, it is a Linux machine (embedded) and these are just the differences with Arduino. One is NOT a processor but is a microcontroller so almost every pin includes a special feature aiming the designers to save as much components as possible. Vice Versa it is expected that on a linux machine, the GPIO goes to the board with the microcontroller, the one you mentioner or the chipkit pi or the same AVR328p. The point is the special case to match pwm with the specific, strongly PLC oriented features of the PiFace Digital.