Raspberry Pi

Yes, its another Raspberry Pi question.

Actually, its more of a "how is the project organized, where things are built and why?"

I've found a "hal_pi_gpio.c" in /src/hal/drivers.
However, the main application makes no attempt to use GPIO pins, whining about the absence of a parallel port.
Stepconf does not produce any signals on the related pins when testing.
What pin numbering scheme is actually used here?

I would like to avoid resurrecting a dinosaur with a parallel port.

I'm trying to figure out where to add support for a custom serial protocol that would satisfy my needs.

So, what did "hal_pi_gpio.c" do? Where did its binary go?

There are no options to use PI GPIO pins, despite the application having been built natively on a Pi 4 (yes, with PREEMPT RT).

The UART is just as fast as any serial port, and any parallel port adapter will be based on shifting bits into registers just to line things up with the parallel port pins. I might as well pipe that into an Arduino (or ShieldBuddy*) and be able to handle error conditions in a well-defined manner.

I've read about setting groups of IO pins in a single operation on an Arduino, and I've already managed this with a ShieldBuddy.


TL;DR:

How do I make a Raspberry Pi HAL work? Where do I start?
I want to configure a basic 4 axis "mill" with spindle control and have the application push bits through a serial port.
I don't care about the voltage levels right now, I just want to watch lines dance around on a scope.

In this link

forum.linuxcnc.org/9-installing-linuxcnc...-io-pins-only#203365

you can find the configuration files (hal and ini) of a minimill using the hal_pi_gpio driver.

Instead at this link you can find the files (hal and xml) of a procedure to drive 2 servos through hal and pyVCP with raspberry pi4 through hap_pi_gpio:

forum.linuxcnc.org/38-general-linuxcnc-q...aspberry-pi-4#222291

Thanks!

I did see that thread earlier, but I'm basically coming from "I know how to build it from source, but I have no idea why things are organized this way".

Still running into problems with miscellaneous this-and-that not being found or loaded when trying to start the GUI.

It would be nice to have complete "turn-key" examples for the Pi, even if they just blink LEDs really fast (or are only entertaining through a scope).

A few years ago because of the Covid i have prepared some videos  and a  pdf tutorial (but in Italian language ..) for my students with some examples of use of the hal_pi_gpio module with devices typically used with Arduino such as LEDs, relays, encoders, DC motors, stepper motors, etc.

In the attachment you will find the sources of the examples. 


Create a directory (e.g. halsample) and copy all files.
Then from the terminal you go to the halsample directory and execute the command:

halrun -I -f <filename>.hal

where <filename> is the name of the corresponding hal file.

Try and let me know

Extremely helpful. Thank you.

So far, I've found stepdir_p.hal and stepdir_v.hal to be useful in eyeballing things.

For others browsing, I should add the GPIO pin tables in hal_pi_gpio.c can be used to determine what physical pins correspond to their HAL symbols.

For example: hal_pi_gpio.pin-19-out actually corresponds to pin # 10 on the GPIO header (of a Pi 4). This can be gleaned from the following snippet in the aforementioned .c file:

In this pdf file there are the instructions.

 

if you don't know Italian language, Google Translate can help you ... 

German for my car, Italian for the mill project, and a good deal of Spanish where I live

Just as it hasn't been mentioned, stepconf isn't able to build a config for the Pi. It is only for parallel port systems.

However, it could still make sense to pretend that you have a parallel port, just to create the file structure and skeleton of the config.