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Shield to test functions of BOE, Activity Board, etc. — Parallax Forums

Shield to test functions of BOE, Activity Board, etc.

John KauffmanJohn Kauffman Posts: 653
in General Discussion
At end of every semester or camp I want to test my sets of various Parallax boards. Anyone have an idea for hardware and code so I can slap a shield on a board, run a progam and get a report by DEBUG or serial.out? At minimum would be pins (even if just light-up, not report to serial). Good to add function of ADC, DAC, supply voltage, memory, anything else that might be broken by students.

I am thinking there must be something like this already used by Parallax to test at end of production.

What I want wouldn't have to be a production product, I can solder up the hardware if I have a schematic / wiring diagram using this:
https://www.parallax.com/product/32999

Here is a start point for code.
http://forums.parallax.com/discussion/107510/basic-stamp-tester

Comments

  • kwinnkwinn Posts: 8,697
    John Kauffman wrote: »
    At end of every semester or camp I want to test my sets of various Parallax boards. Anyone have an idea for hardware and code so I can slap a shield on a board, run a progam and get a report by DEBUG or serial.out? At minimum would be pins (even if just light-up, not report to serial). Good to add function of ADC, DAC, supply voltage, memory, anything else that might be broken by students.

    I am thinking there must be something like this already used by Parallax to test at end of production.

    What I want wouldn't have to be a production product, I can solder up the hardware if I have a schematic / wiring diagram using this:
    https://www.parallax.com/product/32999

    Here is a start point for code.
    http://forums.parallax.com/discussion/107510/basic-stamp-tester

  • kwinnkwinn Posts: 8,697
    That's a good idea. Probably take more than one shield to test most or all of the boards parallax makes. Could try for a single shield with multiple cable harnesses, but that gets complicated very quickly. I have a cable testing program that could be modified to test I/O pins.

    Might be wise to start with a matrix of the boards you want to test and the tests you want to run on them.
  • John KauffmanJohn Kauffman Posts: 653
    I guess start with ActivityBoard.

    Priority #1: The place students are most likely to ruin are the pins.
    Does each pin work for output and input?
    Are adc pins measuring correctly?
    Are dac pins OK?

    Second most likely is a short that burns power supply
    1.8, 3.3 and 5v working

    I think memory is easy to check so can add. But takes long time so maybe make optional.

    Is there a way to test pins to devices like WX, SD, audio?

  • kwinnkwinn Posts: 8,697
    Your post got me thinking about how to test boards so I took a look at the 8 boards listed below and how they could be tested.

    #1 Power:
    The first thing I would do is start with a well regulated current limited power supply between 6V to 7.5V and use an INA219 to measure and log the voltage and current going to the board under test. Would be nice (but not absolutely necessary) to measure the voltage out from the regulators.

    #2 Pins:
    To check the I/O connect a series resistor (~1K should do) to every pin and connect the other side of all the resistors together. Make all of the pins inputs initially, then make one pin an output, toggle the output high and low, input data from the rest of the pins and verify they read the state of the output pin. Set the output pin back to input and set the next pin to output and repeat until all pins have been tested as outputs.

    #3 ADC
    Use the 3.3V from the power supply to verify that the ADC is reading correctly.

    #4 DAC
    Connect the dac outputs to the adc inputs and take readings at 5 voltages.

    The Propeller BoE, Propeller Activity Board, and Propeller Activity Board WX have a lot of pin usage in common so making a single shield to test all three should be possible, although some adapters will be needed. Pin testing would be very similar for all three.

    The Propeller QuickStart, Project Board USB, Protoboard, and FliP provide easy access to all the I/O pins, and the Mini provides access to 18 general I/O pins and the control pins needed to test it. A single shield could be designed for testing them as well.
  • WBA ConsultingWBA Consulting Posts: 2,934
    Nice write-up kwinn! I would say that it is spot on.

    I made up a test fixture 4 years ago for a breakout board for the Cubie board that had VGA, power supply, and an audio amp. I used the Propeller to generate video/audio and fed it through the interface pins of the breakout board to make sure the board was functioning properly. Test took 12 seconds compared to the 2+ minutes of stacking on an actual Cubie board and booting it. Was made using standard spring pin probes and laser cut MDF box for the enclosure. Prop Quickstart was powered by the breakout as a way to confirm voltages.

    I did make my own version of one of those BASIC stamp testers from Chris's thread and still have it: http://forums.parallax.com/discussion/comment/833478/#Comment_833478
  • kwinnkwinn Posts: 8,697
    Thanks Andrew. Early on I did some coding and building for testing electronics and analytical instruments. Found it to be an interesting challenge to try and find problems without modifying the equipment. There are some limits to using only code, but I found it surprising how much could be accomplished.

    The Propeller is a great starting point for this kind of thing. I used a pair of propeller boards to build a tester for wiring harnesses up to 58 pins a couple of years back. Start to finish was less than two weeks.
  • John KauffmanJohn Kauffman Posts: 653
    I have some BOE overlay boards, so will:

    Start with simple set of LEDs and visual inspection with just testing HIGH on pins.
    Then add above trick for INPUT on pins
    Then add transistor-controlled jumper for connect ADC and DAC.

    Thanks.
  • kwinnkwinn Posts: 8,697
    Here is a simple variation on what I suggested. Can test all the accessible pins and produce several voltage levels for testing the adc's. Each adc input voltage is independent of the others so you can test for shorts/crosstalk between channels.
  • kwinnkwinn Posts: 8,697
    Oops, forgot the PDF
    pdf
    pdf
    Module tester.pdf
    68K
  • JonMJonM Posts: 318
    Having a plug in board that tests the connections on the BOE or other board sounds like a really good idea. On the FLiP side, it might be a good idea to protect the pins to the BOE from user error especially when dealing with youngins' . For the Digital pins you could use something like a BS270 MOSFET to drive an LED so the connection to the LED is not direct to the BOE pin. A similar circuit could be done with the ADC/DAC pins as well. Something like a PopSkin that fits over the board with the circuit pre placed for the BOE header would be cool.
  • John KauffmanJohn Kauffman Posts: 653
    I've often wondered how the Ruggeduino concept could be implemented on BOE or ActivityBoard.
    https://rugged-circuits.com/ruggeduino

    It might be a job for the circuit overlay board with the mosfets mounted below.
    https://parallax.com/product/32999

    It terms of buying for my school lab, we would probably accept a pin or two loss per year per set of 12 boards rather than a "MOSFET intercept" board which I assume would cost >$10. The trick is to learn which pins blew.
  • kwinnkwinn Posts: 8,697
    John Kauffman wrote: »
    I've often wondered how the Ruggeduino concept could be implemented on BOE or ActivityBoard.
    https://rugged-circuits.com/ruggeduino

    It might be a job for the circuit overlay board with the mosfets mounted below.
    https://parallax.com/product/32999

    It terms of buying for my school lab, we would probably accept a pin or two loss per year per set of 12 boards rather than a "MOSFET intercept" board which I assume would cost >$10. The trick is to learn which pins blew.

    Nothing is student proof so I have to agree with that last paragraph. Testing the board to find which pins are bad is not a problem though, and a simple plug in board could do that. With a bit of added code it could also do a go/nogo test for the other circuitry on the board.

    I dug out a couple of 1K sips last night and used them to test my PAB-WX board. Works for testing input and output functions and producing voltage steps to test the adc's.
  • kwinnkwinn Posts: 8,697
    Finally got a little quality time with my Propeller board to see what I could come up with to test BoE and PAB boards. Preliminary results attached.
    pdf
    pdf
    Module tester 2.pdf
    258K
    zip
    zip
    PAB-WX Diagnostics V 0.02 - Archive [Date 2017.08.30 Time 02.37].zip
    24K
  • ercoerco Posts: 20,256
    One of my all-favorite bookmarked threads is below, discussing how to test all the pins on a BS2. Several hardware solutions are mentioned, and Tracy Allen's software-only test took the cake for me. As he says, that "open-pin" test method works on other processors too.

    http://forums.parallax.com/discussion/comment/930555/#Comment_930555

  • kwinnkwinn Posts: 8,697
    erco wrote: »
    One of my all-favorite bookmarked threads is below, discussing how to test all the pins on a BS2. Several hardware solutions are mentioned, and Tracy Allen's software-only test took the cake for me. As he says, that "open-pin" test method works on other processors too.

    http://forums.parallax.com/discussion/comment/930555/#Comment_930555

    Wow, thanks for posting this. Have to add that as an initial test.
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