Read Analog Input

Hi everybody,

I would like to read an analog value from Arduino and save the current joint angles when this value overcomes an offset

My questions are:

1. How can I read an analog input from Arduino in Linuxcnc?

2. Can I use the command "Log" to save joint angles into a text file?

Please write soon!

If you need, linuxcnc can read analog value from mesa 7i77 board for example.
But I must say Elisa, that you have purposes that linuxcnc doesn't have as default.
Look this topic as example, possibly you will find something to solve your question.

As I know arduino, it's only microcontroller that work from your program.
As I imagine you can use USB interface or COM inteface to comunicate arduino and PC. Have you successed in comunication of PC and your Arduino program?

Where can I find information about that?

Linuxcnc has an encoder component that will read a frequency from two pins of a parallel port.
Many of the Mesa cards have encoder inputs which can handle higher frequencies.
Also some mesa cards (like the 7i76e) also have some analog to digital inputs but you would need a signal amplifier as they go to 32 volts or so..

To output a frequency from an Arduino, you could establish a timer interrupt service routine that toggled a digital pin on and off and vary that time interval based on the analog input.

But it would be worth describing your application because if you are coding for an Arduino it would not be hard to convert to writing a custom component in Linuxcnc which may negate the need to use an Arduino.

Yes, the application is important, USB should be fine if you don't need high speed.
For example one LinuxCNC user implemented temperature compensation for spindle
growth with a Arduino measuring the spindle temperature and sending the data to
LinuxCNC via a userspace component.