Pendant with 7i73: question with analog inputs

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01 Sep 2024 21:51 #309171 by Ho Er
Hi,
i've built a custom pendant using the 7i73 (connected to my main 7i96s), most stuff works, but I cannot get more than 4 analog inputs working.
Here is how the pendant looks (3D-Joystick for quickly moving the axis and an encoder for exact positioning - modeled after the Estlcam pendant):

Here is how it looks inside - some classic wiring (after a bit twiggling, the 7i73 fits nicely into the free space of the Bopla enclosure):

I have almost everything running in LinuxCNC, but I cannot find any way to use the I4-I7 inputs as analog inputs (I0-I3 work as analog inputs). I actually only need one additional analog input (I4) and asked the MESA support for help - they answered that "That would take a fair amount of changes" and suggested using another card (which would not fit into the enclosure anymore).I checked their website again and they advertise the card as having 8 analog inputs - after digging through the manual however there is some explanation: "Inputs 0 through 7 can read analog signal values however only inputs 0 through 3 are supported for analog input by available interface modes". So even though the hardware supports 8 inputs, the software does not - pretty misleading.

The card is set to NO KEYPAD MODE / NO LCD MODE (W5=DOWN, W6=DOWN, W7=DOWN), I am using inputs IN0-IN3 for analog in, IN5-IN7 for digital, IN8/9 for ENC0 and IN10-15 for digital inputs and would like to use IN4 as analog input.
Here is a screenshot of the hal:


So my question is: has anybody been able to get more than 4 analog inputs working with the 7I73 and how?

Thanks!
The following user(s) said Thank You: tommylight

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02 Sep 2024 01:09 #309177 by COFHAL
In the smart serial configuration in the hal file, you have to enable mode 1, I think that is what enables those inputs as analog, not only the configuration of the jumpers is needed. Right now I don't have my configuration at hand, but tomorrow I can share it with you.

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02 Sep 2024 04:46 - 02 Sep 2024 04:48 #309187 by spumco
Something like:
loadrt [HM2](DRIVER) board_ip=[HM2](IPADDRESS)  config="sserial_port_0=01000000"

After the "=" sign, the first digit is the host board (i.e. 7i96s, 7i76e, etc.), and the 2nd digit is the sserial board connected to the host.

=01000000 - host board mode (7i76e, 7i96S)
=01000000 - sserial daughter board mode (7i73)

Make sure to figure out (i.e not overwite) what your existing host board mode needs to be.
Last edit: 02 Sep 2024 04:48 by spumco.

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02 Sep 2024 05:13 #309188 by cornholio
Yeah that's not the issue. From his screen shot of hal show the OP has everything setup correctly. Communication appears to be good.
The issue is that the OP wants to use more than 4 analogue inputs, but the 7i73 is only reporting 4. The question is how to access the other analogue inputs.

Unfortunately reading the 7i73 manual, it appears only the first four of eight are available.

Would it be possible to ditch the analogue joystick, thereby freeing up the 4 inputs and using pots to set up the jog speed ? Not quite as convenient.

Another option could be an SPI A to D and bit bang the data through.

This is an example using the parallel port, but should be adaptable.
www.wallacecompany.com/machine_shop/EMC2/serial_adc/

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02 Sep 2024 05:35 #309190 by Ho Er
Exactly - the sserial is working correctly, but I can only access analog I0-I3.

As the card was advertised as having 8 inputs, I wonder how they can be acessed - or are the specs on the Mesa webpage simply wrong?

Thanks for the A/D hint - this should work as a workaround, but making the existing hardware work should only be a software thing...?

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02 Sep 2024 05:44 #309191 by cornholio
Not being entirely familiar with the chip used it's hard to say. It cold be a case of having to give up one feature for an other, can't really say.

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02 Sep 2024 10:31 #309203 by zz912
Here store.mesanet.com/index.php?route=produc...oduct&product_id=116 is:

"Up to eight 0.0V to 3.3V analog inputs are also provided. "

But small notes in manual explain:

"Inputs 0 through 7 can read analog signal values however only inputs 0 through 3
are supported for analog input by available interface modes."

So hardware can works with 8 analog inputs, but software can send to LCNC only 4 analog signal.

The only stuff for save this project is if PCW would make "mode 4" for 8 analog inputs.

Another way is to ditch the 7i73 and use an Arduino with a SmartSerial slave.

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02 Sep 2024 14:17 #309212 by PCW
I think what happened is that for modes with both inputs and
MPG encoders, you run out of process data space (96 bits maximum
 in each direction with standard sserial) 8 Analog inputs would require a
mode that dropped at least 3 MPGS.or GP inputs. A mode with 6 analog
inputs may be possible. I can take a look but it may also be limited
by code space.

I will remove the 8 analog input description from the store and manual and I
apologize for the confusion this caused.
The following user(s) said Thank You: tommylight, Clive S, zz912, spumco

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02 Sep 2024 14:57 - 02 Sep 2024 14:57 #309214 by zz912
I think before PCW starts doing anything. Ho Er should define everything he needs.
Numbers of DI, DO, AI, AO, MPG ...
Let PCW not have to redo it.
Last edit: 02 Sep 2024 14:57 by zz912.

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02 Sep 2024 16:15 #309216 by COFHAL
This is what the 7i73 manual says about the analog inputs: Inputs 0 to 7 can read analog signal values, however only inputs 0 to 3 support analog input due to the available interface modes. The analog inputs have a range of 0 to 3.3 V. The normal resolution is 8 bits. All bits can be read as digital inputs. Note: The analog inputs are only accessible in some software modes. This means that technically only 4 of the 8 inputs that say they can read these analog values ​​are available.

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