Raspberry Pi 4

Good luck Gene - wishing you the best while in the "shop"

Chris

unforch, I had to drive 3 hours round trip just to talk to them. Enough to upset the pope. Absolutely everything we talked about, except putting my Freddy McGilicuddy on two pieces of paper, could have been done over the phone by on of the Dr's girls.

According to the dyed cat scans, my blood vessels are a bit tight to allow the device to be implanted thru the groin, so thursday they will install a stent or 3 to stretch them out. But that will require a driver because the twilight shot doesn't wear off fast enough to let me drive myself home.

Then they'll schedule installing the new valve. Another weeks delay, or more. Grrrrr.

And thats all I know.

Take care all.

Cheers, Gene Heskett

Spacehitchhiker42

Did you etch the image to the SD card? I tried balenaEtcher but it gives me an error because the file extension isn't supported. Do I need to try a different etcher? I have tried removing the extension and installing but I get the 4 flashes of the green light which means the start*.elf isn't found. I tried reformatting the sd card and then copying the .tar.gz file and still not working. What am I doing wrong?

RyanG wrote: Spacehitchhiker42

Did you etch the image to the SD card? I tried balenaEtcher but it gives me an error because the file extension isn't supported. Do I need to try a different etcher? I have tried removing the extension and installing but I get the 4 flashes of the green light which means the start*.elf isn't found. I tried reformatting the sd card and then copying the .tar.gz file and still not working. What am I doing wrong?

I got it all figured out, but when I was looking at the GPIO Hal I noticed the pin assignments says they are for the Pi 2/3. Are the GPIO pins for the Pi4 the same as 2/3?

One other question, Has anyone been able to clock the Pi to run it faster. When I tried to do it I got an error stating that it couldn't be done with the image that I got from Spacehitchhiker42. I tried it from the boot sequence when pressing Shift during the boot process. Is there a way to do it through the terminal?

RyanG wrote:

RyanG wrote: I got it all figured out, but when I was looking at the GPIO Hal I noticed the pin assignments says they are for the Pi 2/3. Are the GPIO pins for the Pi4 the same as 2/3?

Yes.

But be aware the HAL driver uses physical pin numbers, not GPIO numbers.

andypugh wrote:

RyanG wrote:

RyanG wrote: I got it all figured out, but when I was looking at the GPIO Hal I noticed the pin assignments says they are for the Pi 2/3. Are the GPIO pins for the Pi4 the same as 2/3?

Yes.

But be aware the HAL driver uses physical pin numbers, not GPIO numbers.

Okay thank you!

This isn't for RyanG in particular, but its for whomever is actually downloading the rpi4-pre-empt-rt.tgz kernel file from my site at geneslinuxbox.net this evening of 11/10/19.. This is a built kernel but please follow John Thorntens recipe to install it on a pi4's sd card. You only need a few megs of it for a realtime kernel install. Its not built for arm64, but for armhf, which you get from installing the raspbian version of debian 10.1. Its running my big sheldon lathe very well, much easier than the rpi3 I took out. IMO armhf should have a smaller stack frame making context switches faster.

You could rebuild it for arm64, and install it on debian 10.1, but I don't think you'll quite get the latency I'm getting. In any event, have fun. And let me know if you hit any problems. The debs for a linuxcnc install are also armhf flavor.

Be aware that I am blocking the bots as they show up.

Cheers All, Gene Heskett.

Gene1934 wrote: This isn't for RyanG in particular, but its for whomever is actually downloading the rpi4-pre-empt-rt.tgz kernel file from my site at geneslinuxbox.net this evening of 11/10/19.. This is a built kernel but please follow John Thorntens recipe to install it on a pi4's sd card. You only need a few megs of it for a realtime kernel install. Its not built for arm64, but for armhf, which you get from installing the raspbian version of debian 10.1. Its running my big sheldon lathe very well, much easier than the rpi3 I took out. IMO armhf should have a smaller stack frame making context switches faster.

You could rebuild it for arm64, and install it on debian 10.1, but I don't think you'll quite get the latency I'm getting. In any event, have fun. And let me know if you hit any problems. The debs for a linuxcnc install are also armhf flavor.

Be aware that I am blocking the bots as they show up.

And a showstopper problem with the kernel file has I hope now been fixed. That bad file has now been replaced with a tar.bz2, 4.19 yadda yadda. Sorry bout the wasted time but it should work now.

Cheers, Gene Heskett.

Cheers All, Gene Heskett.

Hey guys, I have been working on getting my pi 4 setup to run linuxcnc through parallel port but I am not sure how to select Step and Dir from the options provided. What should I be selecting to setup the axis? There is no option for step and dir so I am assuming it should be something else but I don't want to try all of them. I appreciate your time and assistance.

Ryan

You are going to have to setup the hal file manually... there is an example using gpio... Hmmm

github.com/LinuxCNC/linuxcnc/commit/e0dc...52586d505f4b9bcda60d

at the bottom. Remember the GPIo pins in hal are actual pin number on the header (not the rpi numbering)

RyanG wrote: Hey guys, I have been working on getting my pi 4 setup to run linuxcnc through parallel port but I am not sure how to select Step and Dir from the options provided. What should I be selecting to setup the axis? There is no option for step and dir so I am assuming it should be something else but I don't want to try all of them. I appreciate your time and assistance.

Ryan