Bit file for Mesa 7i76e with UART?

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13 Sep 2017 13:47 #98922 by rodw
rodw created the topic: Bit file for Mesa 7i76e with UART?
Is there a bit file that I could install on my 7i76e that replaces the smart serial with a UART?

I'd like to play with RS485
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14 Sep 2017 14:06 #98948 by PCW
PCW replied the topic: Bit file for Mesa 7i76e with UART?
I can make a bitfile with a UART on the 7I76Es expansion connector
_But_

1. the 7I76/7I76E has a RS-422 interface, not RS485 so will only work with 4 wire interfaces (not 2 wire)
2. There is little support for the UART (Packet UART in this case) in LinuxCNC

You might be able to work around (1) with some say 100 Ohm series resistors in the RS-422 TX lines
and wiring the TX and RX together

What kind of command protocol does the plasma use? As far as I know there are only user written components that access the Packet UART (one included example communicates with a gyroscope...)
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14 Sep 2017 20:16 #98968 by rodw
rodw replied the topic: Bit file for Mesa 7i76e with UART?
Peter thanks
Andy pointed me towards this hostmot2 driver via the Developers mailing list
github.com/LinuxCNC/linuxcnc/blob/master...ivers/mesa_uart.comp

The protocol is MODBUS and the plasma machine has a 4 wire interface

See this link for protocol and wiring pinout:
forum.robotsinarchitecture.org/index.php...pic=232.0;attach=335

And yes, I know I'll have to write some code. It would be nice if there was a Hypertherm modbus component for Mesa cards to support your THCAD.
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20 Sep 2017 10:51 #99155 by rodw
rodw replied the topic: Bit file for Mesa 7i76e with UART?
Peter, it would be great if you could find the time to build this bit file. I think it would be very helpful for plasma table builders.
Rod
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23 Sep 2017 02:45 #99301 by PCW
PCW replied the topic: Bit file for Mesa 7i76e with UART?
freeby.mesanet.com/7i76e_7i76x1_PktD.bit

Not sure

1. if the driver is complete
2. How you talk to it
The following user(s) said Thank You: rodw
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23 Sep 2017 04:56 #99306 by rodw
rodw replied the topic: Bit file for Mesa 7i76e with UART?
Peter thanks so much. I'm tied up at a trade show all weekend so it might be a week or so before I can play with this.
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24 Sep 2017 21:55 #99388 by rodw
rodw replied the topic: Bit file for Mesa 7i76e with UART?
Well, I don't have a Hypertherm handy yet so I need some way of emulating one to test this out. I think I'll use an Arduino and a MAX488 chip as per this pinout. www.homebuiltrovs.com/rovforum/viewtopic.php?f=15&t=1047
I had a look at the MAX488 data sheet and it all looks pretty straight forward to convert the Arduino's 2 wire UART via the MAX488 to a 4 wire RS485 connection. The MAX488 pins map directly to the Hypertherm pinout.

One question though. The MAX488 documentation say so to connect a 120 ohm resistor between RX+ and RX- at each end of the link. Is this necessary at the Mesa 7i76e end?
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25 Sep 2017 02:44 #99391 by PCW
PCW replied the topic: Bit file for Mesa 7i76e with UART?
The 7I76E RX pins are already terminated
The following user(s) said Thank You: rodw
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30 Sep 2017 23:01 #99705 by rodw
rodw replied the topic: Bit file for Mesa 7i76e with UART?
I finally found some time to see if I could install the bit file using hm2_eth
loadrt hm2_eth board_ip="10.10.10.10" config="firmware=/home/plasma/linuxcnc/configs/Plasma3.10.01/7i76e_7i76x1_PktD.bit num_encoders=1 num_pwmgens=0 num_stepgens=5 " 

I found that with this configuration, my MPG encoders disappeared, so I had to add back in the " sserial_port_0=2xxxx"
loadrt hm2_eth board_ip="10.10.10.10" config="firmware=/home/plasma/linuxcnc/configs/Plasma3.10.01/7i76e_7i76x1_PktD.bit num_encoders=1 num_pwmgens=0 num_stepgens=5 sserial_port_0=2xxxx" 

I did not think I should be playing with a sserial_port. The output does not show a UART loaded

Do I need to flash the bitfile?

Warning: Spoiler! [ Click to expand ]
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01 Oct 2017 00:01 #99708 by PCW
PCW replied the topic: Bit file for Mesa 7i76e with UART?
The firmware=xxxx does nothing on the 7I76e (or any other Mesa FPGA card that loads its configuration from flash memory)

You need to use mesaflash and program the 7I76E with the new firmware

Note that no hal pins are created by the UART but its pins should show up in the pinout list that's printed when
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