Problems with the last firmware

[dmitri]

I'm moving the topic to MegaDrum Hardware where it belongs.

[therapix]

I have reviewed the cables, capacitors and the clock and I have not found bugs. But do not get PonyProg detect the Atmega.

Besides when I connect the USB cable does not turn toward the LED as before. Windows detects two USB devices (capture), do not know if this is normal or do I have any problem in the PIC18F2550 because they have worked without this one of the 15pF capacitors.

Not to do. I program the PIC18F2550 with ICSP cable through a COM port? if so, what configaracion I put in Winpic800 Settings / Hardware and software, fuses configuration that I have to dump the firmwareV2 this PIC?

Any help is welcome.

[dmitri]

Why do you want to program PIC18F2550? It is already programmed and working.

With Atmega.
First, check that pins 11 and 31 are properly connected to ground (GND).
Second, when USB is and ISP cables are connected, measure voltage between pins 11 and 10 of Atmega. If it is +5 and you're still not able to program Atmega, then it is one of these:
1) Crystal is not working properly. Replace it.
2) LPT port is not working properly. Try another computer.
3) You accidentally programmed fuses on Atmega with wrong values. Either get a new Atmega or get a 1MHz generator and connect it to pin 13 of Atmega (without crystal connected) and try to program it again. See details/explanation at http://www.larsen-b.com/Article/260.html

[dmitri]

Also see this viewtopic.php?p=278#p278 for how you can make a generator.

[therapix]

thanks again, to see if I can fix it.

[japi]

Besides when I connect the USB cable does not turn toward the LED as before. Windows detects two USB devices (capture), do not know if this is normal or do I have any problem in the PIC18F2550 because they have worked without this one of the 15pF capacitors.

I think that "Dispositivo compuesto USB" does not relate to Megadrum, do you have a cellphone connected? Try to disconnect it to see if that device goes away.

If you have "Dispositivo de audio USB" when connecting Megadrum, the 2550 is working, forget about it and program the atmega with a printer(lpt) port, but leave the usb connected as the atmega needs power when programming it.

[therapix]

Hello again. I have not managed to solve the problem. I do not understand because windows detects when I connect the two devices Megadrum. with the USB cable and ISPs do not get connected 5V pin between 10 and 11 of atmega.

Any help is welcome.

[dmitri]

Hello again. I have not managed to solve the problem. I do not understand because windows detects when I connect the two devices Megadrum. with the USB cable and ISPs do not get connected 5V pin between 10 and 11 of atmega.

Any help is welcome.

I'm not quite sure I understand what problem you have now reading the description of the problem.

[therapix]

Sorry for my English.

When I connect the USB and ISP cables not get 5V between the pin's 10 and 11 of the Atmega.

I do not understand because Windows detects two USB devices when I connect the Megadrum. Before only identified one, and it worked properly...?

I changed the clocks of Atmega and Pic18F2550 some of 16Mhz and 12Mhz respectively, have also changed capacitors 15p and 22p, but the problem persists.

I will change the capacitor 470n associated Pic18F2550 in case.

I have reviewed the board for short or bad welds, but apart from a poor soldering of capacitors 22p that comment in this thread, I found no more mistakes.

I tried to dump the firmware V2 for Pic18F2550 with a ICSP cable that I built, but I get the error "hardware not detected." in Winpic800.

if when I change the 470n capacitor, the problem persists, I think Pic18F2550 and Atmega I'll replace...

any advice is welcome.

[dmitri]

Sorry for my English.

When I connect the USB and ISP cables not get 5V between the pin's 10 and 11 of the Atmega.

I do not understand because Windows detects two USB devices when I connect the Megadrum. Before only identified one, and it worked properly...?

I changed the clocks of Atmega and Pic18F2550 some of 16Mhz and 12Mhz respectively, have also changed capacitors 15p and 22p, but the problem persists.

I will change the capacitor 470n associated Pic18F2550 in case.

I have reviewed the board for short or bad welds, but apart from a poor soldering of capacitors 22p that comment in this thread, I found no more mistakes.

I tried to dump the firmware V2 for Pic18F2550 with a ICSP cable that I built, but I get the error "hardware not detected." in Winpic800.

if when I change the 470n capacitor, the problem persists, I think Pic18F2550 and Atmega I'll replace...

any advice is welcome.

Again, don't do anything with PIC18F2550. If Windows shows 'USB Audio Device' in the Device Manager, it is working fine.
Atmega must get +5 between pins 10 and 11, otherwise it is not getting power and it won't work.
1. What is the voltage between ground and pin 20 of PIC18F2550?
2. What is the resistance between pin 20 of PIC18F2550 and pin 10 of Atmega? Is it zero Ohm? If not, what is it?