Raspberry Pi 4

Thorhian wrote:

Thank you Helioz.
Right now I'm just trying to figure out how to power the board and my RPi4.

The Pi doesn't have a set of 5V terminals for power, it has the USB-C (or older microUSB) port and the 40pin header.
Powering the 7C81 via the Pi is theoretically possible but not very practical.
Powering the Pi via the USB connector is marginal at the best of times and I certainly wouldn't want to draw even more current though the Pi into the 7C81 and possibly more Mesa IO boards.
The 40pin header is used to connect the 7C81 so isn't really available for power supply.

The 7C81 on the other hand has proper 5V terminals which are capable of supplying power not only to the 7C81 but also to Pi and Mesa IO modules.

The Pi is a power hungry beast and it's peak power draw is between 1-2A, especially when using WiFi. It is common for Pi's to suffer from Voltage drop when powered via the [older] microUSB ports ..... and that's without any additional periphery. Trust me, I've had plenty of low voltage alarms on my other Pi's and I generally try to avoid powering them via the old microUSB as these interfaces are simply not designed to carry the current required by the Pi.

My linuxCNC Pi is supplied via the 7C81 from a 5V 3A power supply and has never suffered "low voltage" issues.

Please, is there some easy way to get linuxcnc-dev installed?
if I remember correctly before it was something like apt-get install linuxcnc-dev

BeagleBrainz wrote:

Have you seen or tried this
gnipsel.com/linuxcnc/uspace/rpi4-rt.html

I followed these instructions and had linuxcnc running in about 3 or 4 hours. I haven't used it yet, but at least it finally installed.

Does anyone have a link for completely built pi4 images in case this doesn't work for me? No search came up with anything functional, but I might have missed something.

Eventually, I also need to install it on a pi2.

Is there a tutorial for getting the GPIO working? I've used the tutorial to install linuxcnc on my rpi4 and can start it, but no idea how to drive a stepper driver from the GPIO. I know it involves a HAL file but thats about the extent of my knowledge at the moment.

Does anyone have any insight on how fast you can reliably bang a rpi GPIO pin using the hal_rpi_gpio component?

If you are looking for hardware stepping and a small 'pi' controller,
then please look at what our Russian colleagues have done with CNC-32.ru.
I have an orange-pi with linuxcnc ( not machine kit) running very high step rates.
The OrangePi has an ARISC co-processor that can handle the stepping.
I have not yet integrated this into a machine system, but, since a stepper system
configuration without any real hardware still exercises the hardware stepgen...
I can be amazed by running Chips3D in Axis faster than you can read this note.

Please visit orangecnc.gitlab.io/
also information is really scattered , so please see the forum thread
forum.linuxcnc.org/18-computer/39037-lin...e-pi?start=40#177682

tomp (with LinuxCNC when BDI was news)

We tested the project with the ARISC driver at the address you provided, and by writing a message on the 192. page of the forum site, we observed that the system caused a shift in the range of + -0.5 millimeters after 10 minutes of operation. They thanked 192 pages on forum sites, and a servant of allh did not try it on cnc. Do not direct, too, a waste of time.
"Greetings from Turkey"

gtt38 wrote:

If you’re looking for an advice to buy a good board I have more than 20 FPGA different boards and the best one for the price is this one :
a.aliexpress.com/_BThu9V
you can have 96i/o in 3.3v for only 15€
I can share with you a bitfile for this one, the slx25 cost 5 bucks more and works too...

Hi!

I'm interested in those bitfiles.

Also, a beginner question: Do you have the source code for those files? Is it VHDL? Or are they produced by some proprietary Xilinx software/configurator?

Should I make a LCNC SD card image with LCNC 2.8 already configured to run a DLP/LCD printer using the Rpi4? I'm not sure how simple this has to be made for hobbyists to be able to use it.

i think that would be fine

i have installed it with JT's

gnipsel.com/linuxcnc/uspace/rpi4-rt.html

my question remains how to manage GPIO configuration in detail?