MCU not outputting gate

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djarago
 
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Joined: Sun Jul 10, 2005 1:45 am

MCU not outputting gate

Post by djarago »

MCU pin 30/PE1/Gate is only outputting 0v whether i have it in random or in keyboard mode and press keys. Any suggestions as to how to track down what is causing this?

According to the schematic Gate is connected directly to R146 (22kohm). I measured the voltage drop across R146 and it is 0v, however I measured it's resistance and get 46kohm... The voltage on either side of it is 3.05vDC with respect to ground. This doesn't change if I turn the resonance or any other pot.
Last edited by djarago on Tue Nov 08, 2005 7:17 pm, edited 1 time in total.

adafruit
 
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Post by adafruit »

do a continuity test w/your meter to check if that pin is shorted to ground. also check the actual pin of the MCU, not the socket: the socket may be loose.

Guest
 

Post by Guest »

remove the micro before checking the continuity

does any of the digital section work
can you talk to it via usb and load new firmware
is it orientated properly in the socket
is it getting 5v
is the eeprom orientated properly and getting 5v

djarago
 
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Joined: Sun Jul 10, 2005 1:45 am

Post by djarago »

I was holding the probe of the meter directly on the pin of the MCU (above the socket) right where it connects to the package.

The leds and such seem to work. The usb chip worked (before I had it connected to the main board). I haven't tried loading new firmware.


With the MCU removed pin 30 appears to have about 32kohm resistance to ground.

Guest
 

Post by Guest »

do the leds step through a pattern
or light up when you push specific buttons
or are they more randomly flashing

id suggest loading new firmware
what is the resistance between the gate pin and ground

djarago
 
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Joined: Sun Jul 10, 2005 1:45 am

Post by djarago »

The LEDs light when I press a button (but the # keys do not light unless im holding down chain or something like that). In random mode they dont flash, only change when I press a key. The only LED that flashes is tempo and it changes speed when i turn the tempo enc.

The MCU and EEProm both have 5.07vDC across their respective VCC and GND lines.

I'm going to try to reload the firmware now.

djarago
 
Posts: 62
Joined: Sun Jul 10, 2005 1:45 am

Post by djarago »

Looks like I can't upgrade the firmware as javacomm from sun is not available for windows and the new control software only lists comm ports 1 through 4 and my usb serial port is showing up as 6. If i go into advanced settings and try to change it I'm told comm 3 and 4 (and 5) are in use even though they do not show up in device manager. I may be able to fix this though.

djarago
 
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Joined: Sun Jul 10, 2005 1:45 am

Post by djarago »

Well I managed to remove (from registry) my other usb devices that I have installed in the past that 'reserved' comm ports 3 through 5, but now when I use x0xb0x c0ntr0l I get "Exception: IntelHexFileRecord instance has no attribute 'startAddress'.

adafruit
 
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Post by adafruit »

seems like you did not download the firmware file correctly

djarago
 
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Post by djarago »

Correct. IE must have messed it up. I downloaded it again with save as and I didn't get that error, now I get:
Exception: 'The x0xb0x did not respond. Check to be sure that the x0xb0x is in the Bootload mode.

It is in the bootload mode as far as I can tell... so I must have something else screwed.

adafruit
 
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Post by adafruit »

spend a day on this. dozens of people have managed to bootload it with the java software. if it still doesnt work you may have fried your mcu in which case you should order a replacement one.

Guest
 

Post by Guest »

if you want to verify that it is not a hardware problem
remove the micro and measure the resistance to ground
on every pin
something could be shorting out

djarago
 
Posts: 62
Joined: Sun Jul 10, 2005 1:45 am

Post by djarago »

Well the reason I can't get the java to work is because sun doesn't have a javacomm download for windows on the javacomm download page. So either they don't have it anymore or I'm just not seeing it.

I tried running the java software (without downloading javacomm), but it had no place to choose a comm port (im guessing because of my lacking javacomm). When I clicked 'program' it seemed to do nothing at all.


I just checked every pin on the MCU and EEProm. None of them are shorted to ground (aside from pin 20 on the MCU and pin 4 on the eeprom).

extra checking:
pins 3, 7, and 8 on eeprom are shorted to VCC and pin 40 on mcu is shorted to VCC as well.

what I find odd is that when I was trying to trace the gate signal along I found that R146 has no voltage drop, which means there's no current flowing through it, but I couldn't figure out why... actually I just had an idea, but it will have to wait until morning for me to test.

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etaoin
 
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Post by etaoin »

Indeeed, JavaCOMM appears to have gone Linux/Solaris only.

Jonnay
 
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Post by Jonnay »

Merry Christmas. I found it on my drive. http://wiki.jonnay.net/_media/x0x/javacomm20-win32.zip

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