Low Cost Raspberry Pi Contoller Board

How Many Axis do you need

       

little fun-project, almost without soldering, but works and is inexpensive
 

wrote:

How Many Axis do you need

little fun-project, almost without soldering, but works and is inexpensive



 

For this project 5 step/dir channels and some way to control a 3-wire RC servo motor.  I'd go with a 6 channel Mesa card if it wasn't a little pricey and out of stock.  

I've seen that setup you mention, or something similar in the LinuxCNC compatible board list.  Soldering doesn't scare me, code does, I'm a novice/intermediate coder. What I liked about the Mesa board I have on my router, it was virtually plug and play. 

If I can save a few dollars and learn something along the way, maybe I'll give this route a go.  I'll have to check into it.

A 7I92TH/TF and a couple Mach 5 Axis BOBs could do this
(or even without the BOBs if you are careful...)

wrote:

A 7I92TH/TF and a couple Mach 5 Axis BOBs could do this
(or even without the BOBs if you are careful...)
 

Crazy idea, what is the frequency of the spindle PWM signal on a 7i96 card?  Can I co-op that to drive a RC servo.  Or use a spare output and pulse at 50 Hz? Can the I/O handle that kind of duty cycle toggling?

Mesa firmware includes a specific PWMgen for RC servos: RCPWMGen.

This can be added to any Mesa FPGA card. Standard PWMgens tend
to have low resolution when used for RC servos as the full scale
duty cycle of RC servos is quite low ( a few %)

wrote:

Mesa firmware includes a specific PWMgen for RC servos: RCPWMGen.

This can be added to any Mesa FPGA card. Standard PWMgens tend
to have low resolution when used for RC servos as the full scale
duty cycle of RC servos is quite low ( a few %)
 

In my case even low res motion is better than stop to stop action. Out of curiosity what physical pins on a 7i96 would drive the RC servo.