Prop hardware troubleshhooting help

Jonathan

Hi All,

I'm having trouble with a Prop on a proto board. It programs just fine, both to RAM and EEPROM. However, I can't get it to actually DO anything. I am simply trying to toggle any I/O. Double/triple checking through the hook up schematic seems fine.

My first thought was it might be a blown PLL. However, even using the internal OSC doesn't work. I have verified the function of the program I am using on a demoboard. Alll voltages are correct on the correct pins. I am using a 512kBit EEPROM. THe board is battery powered and the batteries are good. I have tried two Prop chips with the same result.

I'm up a stump. Any ideas for further troubleshooting?

Thanks!

Jonathan

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www.madlabs.info - Home of the Hydrogen Fuel Cell Robot

Peter Jakacki

Gee, I'm stumped too due to too little to go on to draw any kind of conclusion kinda stumped. (just my way of saying please provide as much info as possible)

Ok, I'll take a guess and mention that maybe you haven't hooked up all the VDD/VSS pins but this is only a guess. This is mainly a visual so check the continuity not just the voltage.


*Peter*

Jonathan

Jacki,

Yup, I've hooked up all the VSS/VDD pins etc. Havn't checked continuity, but all voltages are at expected levels, with no drop between the Vreg voltage and that measured on the pins.

However, it seems I was wrong about it not working on the internal osc. I *thought* it wasn't, but upon checking it *yet again* it is. I'll check cont, but since it is running on the internal osc, I doubt that is it. Might be I guess, the Prop draws more power when using the external.So, I guess what Ill do now is try another resonator. I sure hope it isn't a blown PLL, because that would mean there is something in my circuit that instantly blows the PLL on power up. That doesn't seem too likely, as there is nothing connected to anything other than the bare minimum to program.

What other info·can I provide?·And thanks for the help!

Jonathan

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www.madlabs.info - Home of the Hydrogen Fuel Cell Robot

Jonathan

Hmmm. So I replaced the resonator. This time I decided to use a socket. Put another 5mHz resonator in, and no joy. These are resonators I ordered from Parallax when I ordered the props, so they should work.

On a whim, I decided to try a 10mHz resonator I had laying around. Change the xinfreq and the PLL settings, and bingo! It works!! Yay, no blown PLL. The question now becomes why don't the Parallax resonators work?

Thanks!

Jonathan

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www.madlabs.info - Home of the Hydrogen Fuel Cell Robot

Newzed

Jonathan, the Prop is designed to work with a crystal, not a resonator.· Use a Digikey CTX051.

Sid

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Yesterday is history, tomorrow is a mystery, and today is a gift.

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·

Chris Savage

I would recommend posting code…It may actually be something in the code unless the same code works on another Propeller Chip.

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Chris Savage
Parallax Tech Support

Jonathan

Chris,

The code works fine on the Demoboard. It also works fine on my board now that I have replaced the resonator I got with the Prop with a Murata 10mHz resonator. Of course, I had to change the xinfreq and PLL settings.

Sid,

It is working with a resonator, just not the one I got from Parallax.

Many thanks!

Jonathan

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www.madlabs.info - Home of the Hydrogen Fuel Cell Robot

RinksCustoms

My prop setup wouldn't work either w/a resonator, works fine with CRYSTALS though, 10MHz, 5MHz, and even a 12Mhz crystal! just watch your PLL settings when trying to keep a stable program since i think your basically overclocking the chip at any crystal over 10MHz.

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Definetly a E³ (Electronics Engineer Extrodinare!)
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