7i96S card arrived what setup is recomended
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28 Apr 2026 14:24 #346009
by PCW
Replied by PCW on topic 7i96S card arrived what setup is recomended
In one picture you have the encoder inputs connected, this may affect test results.
Here is the encoder input circuit, you can check if the 26LS32 is faulty by seeing of the
outputs follow the input state. (the outputs are inverted from the TTL input levels)
Here is the encoder input circuit, you can check if the 26LS32 is faulty by seeing of the
outputs follow the input state. (the outputs are inverted from the TTL input levels)
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- xenon-alien
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28 Apr 2026 19:03 #346019
by xenon-alien
Thanks for the hint how to check the 26LS32. Tomorrow I will try.
You think, maybe it can be the inputs to the main microchip if the 26LS32 works correctly?
Replied by xenon-alien on topic 7i96S card arrived what setup is recomended
Not really understand, but the result is the same, as it was with the TTL encoder.In one picture you have the encoder inputs connected, this may affect test results.
Here is the encoder input circuit, you can check if the 26LS32 is faulty by seeing of the
outputs follow the input state. (the outputs are inverted from the TTL input levels)
Thanks for the hint how to check the 26LS32. Tomorrow I will try.
You think, maybe it can be the inputs to the main microchip if the 26LS32 works correctly?
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28 Apr 2026 19:18 #346020
by PCW
Replied by PCW on topic 7i96S card arrived what setup is recomended
You think, maybe it can be the inputs to the main microchip if the 26LS32 works correctly?
It's quite unlikely that the FPGA has been damaged, much more likely that the 26LS32 has been.
Also the 26LS32 does not connect to the FPGA directly but rather through U13 (74CBT16211
level shifter) If U13 was damaged (by say a mistake in P1 connections) this could cause an
encoder issue as U13 is shared by the encoder interface and the P1 parallel expansion port.
You can do a quick check of U13 with mesaflash (assuming P1 is unconnected):
mesaflash --device ethernet --address [card-address] --rpo 0x1008
This should respond with: 0001FFFF (the all high open circuit port data for the parallel
expansion port = P1). Damaged U13 I/O pins that connect to P1 will typically be stuck low.
It's quite unlikely that the FPGA has been damaged, much more likely that the 26LS32 has been.
Also the 26LS32 does not connect to the FPGA directly but rather through U13 (74CBT16211
level shifter) If U13 was damaged (by say a mistake in P1 connections) this could cause an
encoder issue as U13 is shared by the encoder interface and the P1 parallel expansion port.
You can do a quick check of U13 with mesaflash (assuming P1 is unconnected):
mesaflash --device ethernet --address [card-address] --rpo 0x1008
This should respond with: 0001FFFF (the all high open circuit port data for the parallel
expansion port = P1). Damaged U13 I/O pins that connect to P1 will typically be stuck low.
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29 Apr 2026 05:01 #346030
by xenon-alien
On the table there wont be a phisical connection to P1, just 5v supply.
Here it is (both has the same respond):
Replied by xenon-alien on topic 7i96S card arrived what setup is recomended
To the P1 just connected the axis indexes (1-5 pins - you did the firmware to me) 50-100Om through resistor as you wrote me (5v supply GND to the driver and from the driver back to the P1 through a 100Om resistor)Also the 26LS32 does not connect to the FPGA directly but rather through U13 (74CBT16211
level shifter) If U13 was damaged (by say a mistake in P1 connections) this could cause an
encoder issue as U13 is shared by the encoder interface and the P1 parallel expansion port.
You can do a quick check of U13 with mesaflash (assuming P1 is unconnected):
mesaflash --device ethernet --address [card-address] --rpo 0x1008
This should respond with: 0001FFFF (the all high open circuit port data for the parallel
expansion port = P1). Damaged U13 I/O pins that connect to P1 will typically be stuck low.
On the table there wont be a phisical connection to P1, just 5v supply.
Here it is (both has the same respond):
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29 Apr 2026 05:06 #346031
by tommylight
Replied by tommylight on topic 7i96S card arrived what setup is recomended
If that is the same result for both cards, seems both are OK>
Check wiring and voltage at the Mesa inputs, might be to low to trigger.
Check wiring and voltage at the Mesa inputs, might be to low to trigger.
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29 Apr 2026 07:33 #346032
by xenon-alien
Can I force 5v to this pins (via wire from 5v supply from the stepper pins) to see in hal show will it change or not?
Replied by xenon-alien on topic 7i96S card arrived what setup is recomended
If the pins are correct (3. 5. 13.), there are no movement on the not working channels.Here is the encoder input circuit, you can check if the 26LS32 is faulty by seeing of the
outputs follow the input state. (the outputs are inverted from the TTL input levels)
Can I force 5v to this pins (via wire from 5v supply from the stepper pins) to see in hal show will it change or not?
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