P26 LED Stays on upon turn on

TheTech69 · 2017-10-13 00:21

I have had my Activity Board for a couple of weeks. The LED for P26 stays on immediately upon turn on. There are no programs loaded and cleared RAM and EEPROM every time before shut down.

Any ideas? Defective board.

Thanks,
Jason

Phil Pilgrim (PhiPi) · 2017-10-13 01:43

TheTech69 wrote:

There are no programs loaded and cleared RAM and EEPROM every time before shut down.

How do you "clear" EEPROM?

-Phil

DigitalBob · 2017-10-13 02:57

Write a small program and tell P26 to turn off or cycle on and off. You can use one of the simple spin library programs. If it does nothing and stays on the chip is burnt.

TheTech69 · 2017-10-13 10:32

@Phil - Sorry, wrong choice of words. I haven't used EEPROM yet. I also load a simple program that contains just a return statement. I read one time this allows the chip to go into low power mode.

@DigitalBob - Excellent suggestion!! I'm embarrassed I didn't think of doing that. The LED does work normally...blinks in accordance with programming code. However, the LED turns back on and remains on until I put a coding in for P26 to output low.

Any other thoughts on why the LED remains on?

Electrodude · 2017-10-13 14:16

Can you try "blinking" it between a low output and an input? When it's a low output, the LED should be off, but when it's an input (all pins are inputs after reset), I suspect the LED might turn on for whatever reason. Also try blinking between output high and input - it might just always stay on.

PUB test_26

  'outa[26]~~                ' uncomment this line for output high instead of output low
  
  repeat
    !dira[26]               ' toggle direction
    waitcnt(clkfreq + cnt)  ' wait a second

frank freedman · 2017-10-13 15:33

You said you haven't used eeprom yet. Could be whatever was there when you got the board is the code lighting up the led. Copy the do nothing code from the prop ed book and tell it to program to eeprom. Maybe that will cure the led on.

DigitalBob · 2017-10-13 21:49

Frank has a good suggestion. Load F11 to eprom on the prop tool with code that makes the pin low. Then cycle the power.

Ken Gracey · 2017-10-14 00:17

This might be part of our test procedure program. I could check into it if desired.

The ideas above are certainly appropriate.

Ken Gracey

TheTech69 · 2017-10-14 00:19

I loaded program to EEPROM that makes P26 low and cycled power. During the quick boot process (?) of the chip P26 was on, then the program in EEPROM took over and P26 was low.

@Electrodude - I loaded your code and ran it. The toggling of input to output pin worked fine.

During any loading (F10 or F11) the P26 LED is on. Not sure if that helps, but thought I would mention it.

Thank you all for your assistance with this.

Jason

TheTech69 · 2017-10-14 00:26

@ Mr. Gracey - Thank you for taking the time and the interest in my little problem. If this is an indicator of a possible problem with the board I definitely would like to know. However, I am just a retired electronics maintenance Marine who likes to tinker and learn. The board still functions just fine for the little exercises I do out of the Propeller Education Kit Labs: Fundamentals book.

Sincerely,
Jason

Ken Gracey · 2017-10-14 00:33

Yep, it seems your board is just fine. As you start to use the different hardware you'll see it all works

It's made right here, in Rocklin, California USA by American workers (and some veterans too) and includes our guarantee of workmanship! Even if you manage to blow it up I'll replace it for you.

Go forth and program. I mean, go Spin and program. Or Blockly, or ASM, or Tachyon, or whatever you want.

Ken Gracey

TheTech69 · 2017-10-14 00:39

Mr. Gracey,

Copy that. The LED was never on when I first turned it on, so I thought something might be wrong with the board. LED sure is bright!

Thank you for taking the time to assist with this issue.

P26 LED Stays on upon turn on

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