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| Parallax Forums > Public Forums > Propeller Chip > EEPROM Failure? Wierd Problem. | Forum Quick Jump
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redrocker
Registered Member
      
Date Joined Apr 2009
Total Posts : 10
| Posted 10/30/2009 11:40 AM (GMT -8) |   | The problem is my USB Protoboard will only work if the usb cable from the computer is still plugged in during boot up.
About an hour ago I was ecstatic. I had just finished the first working version of my very first project. Everything is running fine, so I decide to download the program to the EEPROM and remove the USB Cable.
When I the switch on the power at first everything seems normal. The LCD screen has loaded the first page and gives me a menu, but when I press a button on the key pad nothing happens.
Has anyone ever had this problem before?
More INFO:
The program is loaded and verified in EEPROM.
If I remove the USB cable shortly after power up everything works fine. (?)
There are many devices in the project. So I thought I would first trouble shoot the keypad and LCD. I wrote a simple test program that displays a number for each key I press on the LCD. I then demonstrated that the program works on my PPDB( parallax professional development board). That is I loaded the program to EEPROM, unplug usb cable, powered off/on to success.
However, when I load the exact same program (to EEPROM) to the USB protoboard, unplug usb cable, power on--Nothing. Do the same thing with the cable in=success.
Any suggestions would be greatly appreciated.
Thanks
Adam | | Back to Top | | |
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James Long
Lil Brother SMT Assembly Services
Date Joined Aug 2004
Total Posts : 976
| Posted 10/30/2009 11:58 AM (GMT -8) | | redrocker said...
The problem is my USB Protoboard will only work if the usb cable from the computer is still plugged in during boot up.
About an hour ago I was ecstatic. I had just finished the first working version of my very first project. Everything is running fine, so I decide to download the program to the EEPROM and remove the USB Cable.
When I the switch on the power at first everything seems normal. The LCD screen has loaded the first page and gives me a menu, but when I press a button on the key pad nothing happens.
Has anyone ever had this problem before?
More INFO:
The program is loaded and verified in EEPROM.
If I remove the USB cable shortly after power up everything works fine. (?)
There are many devices in the project. So I thought I would first trouble shoot the keypad and LCD. I wrote a simple test program that displays a number for each key I press on the LCD. I then demonstrated that the program works on my PPDB( parallax professional development board). That is I loaded the program to EEPROM, unplug usb cable, powered off/on to success.
However, when I load the exact same program (to EEPROM) to the USB protoboard, unplug usb cable, power on--Nothing. Do the same thing with the cable in=success.
Any suggestions would be greatly appreciated.
Thanks
Adam
There are a couple of things you didn't mention.
Are you powering the circuit from the same supply for testing both items?
This sounds like a power problem, not an EEPROM problem.
If you can cycle power after a download to the USB protoboard, with the USB cable plugged in, and the propeller work....then the EEPROM is working correctly. After power off the EEPROM has to supply the program to run.
EDIT.......sorry....are you saying if you boot the protoboard with the cable it works, even after the cable is unplugged???
James L
James L
Partner/Designer
Lil Brother SMT Assembly Services
Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!Post Edited (James Long) : 10/30/2009 8:11:46 PM GMT | | Back to Top | | |
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mikediv
Registered Member
Date Joined Dec 2007
Total Posts : 455
| Posted 10/30/2009 2:02 PM (GMT -8) | | I agree with Red but we still need more info I had something similar happen and it turned out to be power related with the USB cable plugged in it seemed to supply some power to my proto board enough to work but when I un-plugged cable the batteries were to low
I have seen this happen a few times I do not have a PPDB is it the same I/O as your proto board? are you using the same size eeproms in both circuits? 256,512,1024? | | Back to Top | | |
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MagIO2
Registered Member
Date Joined Mar 2009
Total Posts : 595
| Posted 10/30/2009 2:15 PM (GMT -8) | | | Is there a pullup on the propeller reset line? Maybe the USB-chip has a free floating output which tends to ground in case there is no power via USB-plug. | | Back to Top | | |
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Phil Pilgrim (PhiPi)
Registered Member
Date Joined Feb 2006
Total Posts : 5998
| Posted 10/30/2009 3:21 PM (GMT -8) | | | | |
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