I have killed (hopefully only wounded) my Eval Board

I was was working on an object for the Ping. At first I forgot about the inline series resistor on the signal pin. I added a 1 k ohm resistor. The configuration was gnd to Ping, 5V to Ping, pin 42 to breadboard to 1 k ohm resistor to Ping. At last I noticed the following. If I hooked the Propscope to the resistor leg closest to the Ping the return signal was a little over 3 volts. If I hooked the Propscope to the resistor leg nearer the Prop2 Eval board, the return signal was visible and changed as I moved an object closer/farther from the Ping but was only milliVolts. But I was still producing the trigger pulse and writing serial data to Propeller Serial Terminal. Then I think I may have killed the board by shorting out 5V to V4047 while trying to measure power to the Ping. The voltage selection jumper was set to VIO.

Current status.

  oscmode = $010c3f04
  freq = 160_000_000
   pins :  "pins2.spin2"

PUB Main | i
    clkset(oscmode, freq)
       waitcnt(clkfreq / 5 + cnt)
       waitcnt(clkfreq / 5 + cnt)
Pin 57 only blinks one time
CON 'Constants section 
  oscmode = $010c3f04
  freq = 160_000_000
  baud = 230400                     'must configure RUN command to match this
  rx = 63
  tx = 62


    ser : "SmartSerial.spin2"
PUB Main    | pause, time
    clkset(oscmode, freq)
    ser.start(rx, tx, 0, baud)                  'start up serial terminal
    waitcnt(2 * freq)                           'wait to open terminal
       ser.str(string("Help "))
       ser.str(string("Help2 "))
produces no output on PST

Parallax, if you want, I can return the board for a post mortem.

I will clean up/document the library I was working on and post it, probably next week.

John Abshier


  • Peter JakackiPeter Jakacki Posts: 9,921
    edited 2019-03-15 - 00:18:59
    TAQOZ is built into ROM for many purposes but one is to check hardware. If you escape into TAQOZ ( [>] [space] [esc] ) with your serial terminal connected then you can type 57 BLINK and know it is working or not. The same goes for any other pin. However if only one pin is damaged it hardly seems a good reason to send it back since you still have 63 pins to work with :)

    Don't forget the lsio command which lists the state of the pins too:
    After the [>] [space] [esc] you will have this on your terminal, just type those commands.
    Cold start
      Parallax P2  .:.:--TAQOZ--:.:.  V1.0--142          180530-0135
    TAQOZ# 57 BLINK  ok
    TAQOZ# lsio 
    =:ddd~d~~~~~~ddd~ddd~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ddd~d~~~h ok
  • On P1, something like that would kill the PLL first...
    Wonder if that's true for P2 too...

    If TAQOZ works in RC mode, worth a try...
  • John, you can send the board back to Parallax, if you want, attn: Chantal Woods-Jones.

    I will let her know it's coming and we will see what we can do to fix it.

    It might be good to determine WHAT broke, first, if possible, as a shorter-time solution may be available.

    Are you showing any signs of life?
  • evanhevanh Posts: 10,227
    edited 2019-03-15 - 01:33:28
    Do you know what position the V4047 supply jumper was set to? If it was to the outer position (LDO regulator) then there is a good chance of only local group of four eight I/O fried. If it was set to inner (3v3 switcher) then all I/O pins will be fried, including the oscillator circuits. I suspect the latter.

    This is an accessory connector issue. The 5 V supply pin needs relocated to other side of the two GND pins. Either both be 5 V or the second pin could be a 5 V tolerant signal. This way any accidental short will be harmless to GND or that tolerant pin. But this would require incompatible reordering of pinout.
  • John,

    Chantal gave me your your board. I tested all of the voltage regulators, and they all work. All of the I/O pins on V4047 output just fine, but V3239 was shorted to ground, so those pins are unusable.
  • Thanks. I am willing to pay for return.

    John Abshier
  • y'all scaring me about attempting to use sensors on the board. I tried to use the ping myself also a gps. We need more info regarding 5 vdc input to the silicon. This is to protect our sacred engineering samples. Mine will be enshrined on the wall after I get the next iteration and the next until the production sample is in my hands. Never to be used again. I have blown up enough p1 chips due to accidents. I do not want to blow up this opportunity to be on the ground floor. So to all be careful. Shield first on the P1 then transition to the p2 evaluation board. I am fearful of blowing up my eval board. So I am very careful to not blow it up. And am limiting my code to my level of understanding to not screw up my favorite chip.
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