Raspberry Pi 4

Gene1934
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01 Jan 2020 22:08 #153743 by Gene1934

Replied by Gene1934 on topic Raspberry Pi 4

You said in your email you were using a 5i25/7i78 combo. That's intel stuff, while this is for an r-pi4. Or are you considering changing? Just curious :-)

Cheers, Gene Heskett
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"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <geneslinuxbox.net:6309/gene>

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gtt38
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01 Jan 2020 23:25 #153752 by gtt38

Replied by gtt38 on topic Raspberry Pi 4

Maybe yeah
It's a small lathe and a small computer could be better, it's driving by an old computer but with a really good latency.
I think i'm gonna buy the 7c81 to drive the 7i78 if graphics on RPI4 are good.
I have many 3d printers too and i hope to drive one of them with linuxcnc, a XC6SLX9 and a STM32 for the analog input/outputs.

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Gene1934
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02 Jan 2020 02:06 #153763 by Gene1934

Replied by Gene1934 on topic Raspberry Pi 4

gfx on the rpi4 are equal to, or in some cases faster than wintel stuff, at least up to 1920x1080. I don't have any 4k stuff. Yet.

Faster than the gfx on a D-525-MW atom board I have 2 of driving other machines, but they have 4 u-sec latencies, so can drive steppers with software stepping, with some speed loss. 5i25's are so cheap I have then in all 3 wintel boxes now. Either with 7i76D's or std but modified bobs, I've ripped some of the opto stuff out of SainSmart input circuitry because it was too slow. Piece of cake for a CET. which I am.

Take care, but have fun doing it!

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gtt38
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02 Jan 2020 22:00 #153826 by gtt38

Replied by gtt38 on topic Raspberry Pi 4

I just found a good dev board on aliexpress
A XC6SLX25 without ddr ram with a 50Mhz oscillator.
fr.aliexpress.com/item/4000141655235.html
Let's see if i can mod the Hostmot2 firmware to use it in SPI mode.
Or maybe use it in ETH mode ?
It would be simple to create a "motherboard" for this small module (2mm pitch) to create a small PLC, with linuxcnc hal and classiclader with or without graphical interface up to 192 i/o available in 3.3V

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Gene1934
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02 Jan 2020 22:54 #153831 by Gene1934

Replied by Gene1934 on topic Raspberry Pi 4

50 MHz is the top speed for that SPI. Peter, I think, runs the spi stuff at 200 so he has time to do other stuff.

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gtt38
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03 Jan 2020 08:24 #153872 by gtt38

Replied by gtt38 on topic Raspberry Pi 4

50Mhz is not the speed of the SPI, it's the oscillator soldered on the dev board, like in Mesa board (you can look at your 7I90 you will see a 50Mhz oscillator )
i found many Xillinx dev board but sometimes with 25Mhz and 100Mhz oscillator. my goal is to be as close as Mesa board to limit modifications to Hostmot2

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Gene1934
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03 Jan 2020 09:41 #153875 by Gene1934

Replied by Gene1934 on topic Raspberry Pi 4

And is the sheckles you save worth the effort? The Mesa stuff just works. Sure, in my case the 7i90 needs three 7i42TA's because the 7i90 is a 3.3 volt max card and I had a huge noise problem early on, brings it up to about $200 but it sure works nice and wires up easily. And with 72 I/O I'll never run out of I/O even if I replace my tool post with a cnc'd turret. I haven't taken inventory but probably have 40 or more empty lines to use yet. ATM I'm using 2 stepgens, one pwmgen and 3 encoders. The pwmgen is driving a spinx1 to run the vfd. The 2nd and 3rd encoders are replacing the hand cranks with encoder dials so I can drive it by hand too.

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gtt38
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03 Jan 2020 10:02 #153878 by gtt38

Replied by gtt38 on topic Raspberry Pi 4

Mesa board are really beatiful and really cheap for the protection (5v tolerant etc...), that's why i'm gonna buy the 7c81 for my lathe. With my 7i78 it will run good i think.
I'm looking for cheap solution too, a raspberry is a cheap computer, and driving 3dprinters or laser cutters could be nice and better than arduino.
I have a cheap CPLD board too like this :
www.openimpulse.com/blog/products-page/p...d-development-board/
based on XC9572XL
hostmot2 SPI on a small board like this could be enough to drive a 3D printer in 3.3V

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Gene1934
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03 Jan 2020 10:30 #153883 by Gene1934

Replied by Gene1934 on topic Raspberry Pi 4

It does look interesting if I wanted to learn yet another language. But at my age, 85, I'd much rather throw money at it. If I had the money. I'd like to have a 3d printer, but I am out of room in the garage. And with my recent health problem, my parts list is beginning to look like the 6 million dollar man. I also have a couple pieces of furniture cut out to finish which I hope to complete before I miss roll call. When that's done and delivered, I might have room for a 3d. If I've got the giddyup left. We'll have to wait and see.

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gtt38
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04 Jan 2020 20:03 #154014 by gtt38

Replied by gtt38 on topic Raspberry Pi 4

so i made an image with Gene repo and latest driver it works pretty good and it's quick to create.
unfortunatly same SPI1 error (SPI0 is working really good)

pi@LinuxCNC:~ $ halrun
halcmd: loadrt hostmot2
Note: Using POSIX realtime
hm2: loading Mesa HostMot2 driver version 0.15
halcmd: loadrt hm2_rpspi spi_probe=16 spi_debug=5 spiclk_rate=5000 spiclk_rate_rd=5000
hm2_rpspi: Platform: Raspberry Pi 4 Model B Rev 1.1
hm2_rpspi: Base address 0xfe000000 size 0x01800000
hm2_rpspi: Mapped peripherals from 0xfe000000 (size 0x01800000) to gpio:0x0xb4c80000, spi:0x0xb4c84000, aux:0x0xb4c95000
hm2_rpspi: SPI1/CE2 clock rate: 5000000/5000000 Hz, VPU clock rate: 500000000 Hz
hm2_rpspi: SPI1/CE2 write clock rate calculated: 5000000 Hz (clkdiv=100)
hm2_rpspi: SPI1/CE2 read clock rate calculated: 5000000 Hz (clkdiv=100)
hm2_rpspi: SPI1/CE2 Invalid cookie, read: 00000000 00000000 00000000, expected: 55aacafe 54534f48 32544f4d
hm2_rpspi: SPI1/CE2 No drive seen on MISO line (kept at pull-down level). No board connected or bad connection?
hm2_rpspi: rtapi_app_main: No such device (-19)
<stdin>:2: waitpid failed /usr/bin/rtapi_app hm2_rpspi
<stdin>:2: /usr/bin/rtapi_app exited without becoming ready
<stdin>:2: insmod for hm2_rpspi failed, returned -1

i can try on CE0 or CE1 but i think it's the same...

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