7i85 GPIO
11 Sep 2022 23:51 #251710
by JacobRush
I find myself needing some 5v inputs/outputs and I have several unused serial ports on my 7i85. I've tried:
loadrt hm2_eth board_ip="10.10.10.10" config="sserial_port_0=00XXX"
Thinking that would disable the unused serial ports, freeing them up for GPIO. I only need sserial 0 and 1.
But I don't see any additional GPIO pins available.
My setup is a 7i92 -> 7i85 -> 7I83/7i84
I show GPIO pins 0-33 regardless of sserial_port settings. I believe these represent pins on my 7i92? Speaking of... How do I find out how the GPIO pins map to physical pins?
loadrt hm2_eth board_ip="10.10.10.10" config="sserial_port_0=00XXX"
Thinking that would disable the unused serial ports, freeing them up for GPIO. I only need sserial 0 and 1.
But I don't see any additional GPIO pins available.
My setup is a 7i92 -> 7i85 -> 7I83/7i84
I show GPIO pins 0-33 regardless of sserial_port settings. I believe these represent pins on my 7i92? Speaking of... How do I find out how the GPIO pins map to physical pins?
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12 Sep 2022 00:40 #251715
by JacobRush
Ah, that makes sense.
I can't quite make sense of how the pins map to GPIO 0-33. Does the below output from mesaflash tell me?
For example I'd like to use TB1-20 as an input and TB1-21 as an output.
I can't quite make sense of how the pins map to GPIO 0-33. Does the below output from mesaflash tell me?
For example I'd like to use TB1-20 as an input and TB1-21 as an output.
IO Connections for P2 -> 7I85
Pin# I/O Pri. func Sec. func Chan Sec. Pin func Sec. Pin Dir
TB1-19,20 0 IOPort SSerial 0 RXData4 (In)
TB1-21,22 1 IOPort SSerial 0 TXData4 (Out)
TB1-11,12 2 IOPort SSerial 0 RXData3 (In)
TB1-13,14 3 IOPort SSerial 0 TXData3 (Out)
TB1-3,4 4 IOPort SSerial 0 RXData2 (In)
TB1-5,6 5 IOPort SSerial 0 TXData2 (Out)
TB2-19,20 6 IOPort SSerial 0 RXData1 (In)
TB2-21,22 7 IOPort SSerial 0 TXData1 (Out)
TB2-11,12 8 IOPort SSerial 0 RXData0 (In)
TB2-13,14 9 IOPort SSerial 0 TXData0 (Out)
Internal-EncMux 10 IOPort MuxedQCountSel 0 MuxSel0 (Out)
TB3-1,2,9,10 11 IOPort MuxedQCount 0 MuxQ-A (In)
TB3-4,5,12,13 12 IOPort MuxedQCount 0 MuxQ-B (In)
TB3-7,8,12,13 13 IOPort MuxedQCount 0 MuxQ-IDX (In)
TB3-17,18,TB2-1,2 14 IOPort MuxedQCount 1 MuxQ-A (In)
TB3-20,21,TB2-4,5 15 IOPort MuxedQCount 1 MuxQ-B (In)
TB3-23,24,TB2-7,8 16 IOPort MuxedQCount 1 MuxQ-IDX (In)Please Log in or Create an account to join the conversation.
12 Sep 2022 01:20 - 12 Sep 2022 02:55 #251716
by PCW
The input and outputs are differential
For outputs you just choose the inverted or non-inverted pin (TB1 21 or 22)
Inputs are not so easy as these are differential and terminated
(with 120 Ohms across TB1 19,20). You can use these as 5V inputs
if you terminate one of the input pair with a stiff say 1.6V reference
and drive the other pin with a series resistor (say 470 Ohm)
Note that you can use a spare encoder input (say a unused index pin) as a 5V input
For outputs you just choose the inverted or non-inverted pin (TB1 21 or 22)
Inputs are not so easy as these are differential and terminated
(with 120 Ohms across TB1 19,20). You can use these as 5V inputs
if you terminate one of the input pair with a stiff say 1.6V reference
and drive the other pin with a series resistor (say 470 Ohm)
Note that you can use a spare encoder input (say a unused index pin) as a 5V input
Last edit: 12 Sep 2022 02:55 by PCW.
The following user(s) said Thank You: JacobRush
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