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Noobie Question about bad chips — Parallax Forums

Noobie Question about bad chips

sjogansjogan Posts: 17
edited 2009-09-20 06:22 in Propeller 1
If I have a bad Propeller chip, would a (F7) Identify Hardware work? I am trying to figure out if I have a bad chip. My suspicion is that I do not. The F7 comes back with "Propeller chip 1 found in COM 6". I must have bad wiring.

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-09-19 23:59
    There are several failure modes (e.g. bad pin, PLL failure) that would still permit a chip to ID. What leads you to suspect that something is wrong with it?

    -Phil
  • Mike GreenMike Green Posts: 23,101
    edited 2009-09-20 00:03
    If you had a completely broken Propeller chip, it would not identify itself. Do remember that you can damage I/O pins other than 28-31 and you can damage the part of the chip that multiplies the crystal frequency to get the system clock and the chip will still identify itself and download programs. You can check for this by writing programs that use the RCFAST clock. They won't be able to do video nor accurate serial I/O since the timing for the serial I/O won't be accurate enough and the speed isn't high enough for video, but you can do other testing, like checking out the operation of I/O pins 0-27.
  • sjogansjogan Posts: 17
    edited 2009-09-20 01:51
    I am using a PE Platform - 40 Pin DIP. I was able to get a simple blinky program running on it just before UPENE 2009. The code was:

    Ch3-Ex06 - Blinker1
    {{ Blinker1.spin }}

    OBJ
    LED : "(Ch3-Ex06)-Output"

    PUB Main
    {Toggle pins at different rates, simultaneously}
    LED.Start(16, 3_000_000, 10)
    LED.Toggle(17, 2_000_000, 20)


    I removed the 9-vold battery, unhooked it and put it away for a few weeks and when i pulled it out yesterday and plugged it all back in, my LEDs at pins 16 & 17 lit up for a sec and now will not.

    I have tried other pins to no avail and have also tried this following code: (with appropriate LED at pin 3 and pushbutton at pin 18.

    PushbuttonLedTest-v1.0
    ''This code example is from Propeller Education Kit Labs: Fundamentals, v1.1.
    ''A .pdf copy of the book is available from www.parallax.com, and also through
    ''the Propeller Tool software's Help menu (v1.2.6 or newer).
    ''
    ''File: PushbuttonLedTest.spin
    ''Test program for the Propeller Education Lab "PE Platform Setup"

    CON

    _clkmode = xtal1 + pll16x ' Feedback and PLL multiplier
    _xinfreq = 5_000_000 ' External oscillator = 5 MHz

    LEDs_START = 0 ' Start of I/O pin group for on/off signals
    LEDs_END = 15 ' End of I/O pin group for on/off signals
    PUSHBUTTON = 18 ' Pushbutton Input Pin

    PUB ButtonBlinkSpeed ' Main method

    '' Sends on/off (3.3 V / 0 V) signals at approximately 2 Hz.

    dira[noparse][[/noparse]LEDs_START..LEDs_END]~~ ' Set entire pin group to output

    repeat ' Endless loop

    ! outa[noparse][[/noparse]LEDs_START..LEDs_END] ' Change the state of pin group

    if ina[noparse][[/noparse]PUSHBUTTON] == 1 ' If pushbutton pressed
    waitcnt(clkfreq / 4 + cnt) ' Wait 1/4 second -> 2 Hz
    else ' If pushbutton not pressed
    waitcnt(clkfreq / 20 + cnt) ' Wait 1/20 second -> 10 Hz



    I have checked the power connectors for continuity and have 3.2 volts across the board.

    I do not think it is the chip with it able to validate an F7, since I was not doing anything extreme. But....


    any ideas on where to look or check for would be appreciated.
  • BEEPBEEP Posts: 58
    edited 2009-09-20 06:22
    "I have checked the power connectors for continuity and have 3.2 volts across the board. "
    Just to be sure, replace the battery.
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