Propeller C3 - Odd issues, dead chip?
Chorca
Posts: 3
So, I have a C3, works great. Been using it to talk to a VFD and draw things on it, that kinda stuff.
Last night, I got the Propeller out, powered up the VFD (without the propeller being powered via USB) and it came on, but the power light on the propeller blipped once. I thought nothing of it, disconnected everything, and reassembled the wires onto the new LED matrix I have, hoping to drive it.
After much frustration of not getting the display to show anything, I started checking the pins. Found that all the pins are floating. That's odd. So far, I've left the test code on the EEPROM and have just been writing to RAM, since they're all just programs I'm playing around with anyway. But for some reason, I'm not able to get the pins to change.
So I try the simplest program, setting pin 15 (the LED/VGA buffer on the C3) to high and low to see if I can get anything to happen. Nothing. No lights. The odd part is that, when I power it off and back on, the program it reads from EEPROM (the C3 test suite) works just fine, lights the LED, and even displays video on the VGA port. Seems to run without issue. Yet any program I load from RAM won't work.
I updated my Propeller software to the latest version, downloaded the C3 test code, and proceeded to try and run it from RAM. It downloads, verifies the RAM download went fine, then nothing happens. Power cycle, and the exact same program it reads from EEPROM works fine.
So I had the great idea to try and rewrite the EEPROM with the same test program, to see if that did anything. Well, it did do something, and that something was to not work properly again. Now, power cycling does nothing. The chip is detected by the computer, I can download to RAM and EEPROM all day long, but the I/O just seems to be floating around 1.8V, and I can't seem to control any of it. Test programs I've downloaded won't work, nor will my own.
I'm kind of at a loss as to what's going on here. The best I can think is that the I/O was burnt up somehow, and now it won't write to the EEPROM properly, or control the pins. The odd part is that the VGA buffer was all controlled by the same pins, but for some reason the EEPROM version of the code worked fine, but the RAM version wouldn't (Until i overwrote the EEPROM, now neither works).
This is on a computer I've had no problems with using on the Propeller before, and it's the same one I've used to write my other software, no changes. Just all of a sudden, the C3 stopped working. I've tried rebooting, different cables (using high quality 1.5' with ferrite) etc, but nothing seems to change.
Any ideas?
Last night, I got the Propeller out, powered up the VFD (without the propeller being powered via USB) and it came on, but the power light on the propeller blipped once. I thought nothing of it, disconnected everything, and reassembled the wires onto the new LED matrix I have, hoping to drive it.
After much frustration of not getting the display to show anything, I started checking the pins. Found that all the pins are floating. That's odd. So far, I've left the test code on the EEPROM and have just been writing to RAM, since they're all just programs I'm playing around with anyway. But for some reason, I'm not able to get the pins to change.
So I try the simplest program, setting pin 15 (the LED/VGA buffer on the C3) to high and low to see if I can get anything to happen. Nothing. No lights. The odd part is that, when I power it off and back on, the program it reads from EEPROM (the C3 test suite) works just fine, lights the LED, and even displays video on the VGA port. Seems to run without issue. Yet any program I load from RAM won't work.
I updated my Propeller software to the latest version, downloaded the C3 test code, and proceeded to try and run it from RAM. It downloads, verifies the RAM download went fine, then nothing happens. Power cycle, and the exact same program it reads from EEPROM works fine.
So I had the great idea to try and rewrite the EEPROM with the same test program, to see if that did anything. Well, it did do something, and that something was to not work properly again. Now, power cycling does nothing. The chip is detected by the computer, I can download to RAM and EEPROM all day long, but the I/O just seems to be floating around 1.8V, and I can't seem to control any of it. Test programs I've downloaded won't work, nor will my own.
I'm kind of at a loss as to what's going on here. The best I can think is that the I/O was burnt up somehow, and now it won't write to the EEPROM properly, or control the pins. The odd part is that the VGA buffer was all controlled by the same pins, but for some reason the EEPROM version of the code worked fine, but the RAM version wouldn't (Until i overwrote the EEPROM, now neither works).
This is on a computer I've had no problems with using on the Propeller before, and it's the same one I've used to write my other software, no changes. Just all of a sudden, the C3 stopped working. I've tried rebooting, different cables (using high quality 1.5' with ferrite) etc, but nothing seems to change.
Any ideas?
Comments
I suggest you give Parallax Tech Support a call. This sounds like something that needs to be debugged with real-time interactive help rather than through the forum.
One of the C3 test programs I was using, the VGA test in particular (c3_vga_demo_010), has this line set:
Unfortunately, that is not correct for the default configuration of the C3. It ships with a 5Mhz crystal onboard, however, XTAL2 is for "Medium Speed (8Mhz to 32Mhz) Crystal" (from the Propeller Manual)
XTAL1 would be the proper code for that line, (4Mhz to 16Mhz) and the symptom of using the wrong line is interesting: At lower speeds, the processor will run fine, (8x or slower multiplier in my testing) however, running at 16x multiplier will cause issues such as it only successfully starting the program once out of every 10 or so times the reset button is hit, and never if the power switch or USB power is cycled. I made the change to the code and it worked fine.
I'm no expert with microcontrollers, so I'm pretty sure I just copied from the wrong code. My fault. Either way, the code for that C3 test program doesn't seem to be correct.
I don't have the code i was having issues with in front of me right now, so I can't check for sure that this is the issue, but I'll look when I get home and if so, I'll mark this solved.
http://forums.parallax.com/showthread.php?131289-Fyi-C3_vga_demo_010
Andre, could you correct the code on the FTP site,. pretty please?