Philippines Megadrum (video)

[dmitri]

Edit: Also found that R9-R16 was changed from 6k8 to 4k7. Should I follow that or can I leave them at 6k8?

Leave them as they are at the moment, but in the future it's better change them to 4k7

[dmitri]

Important update!

The thing that on all inputs you used, Max Level was 'auto set' as 997 is alerting. You should be able to set 'gain' all the way up to the maximum 8. Even the default is 4! Something is not right with your MegaDrum. As a first step I would check values of R17-R20 resistors.
As a second step I would disconnect R19,R20 altogether thus forcing 'gain' to 4 regardless of settings in the configuration. Without R19,R20 you should see a voltage close 2.5V on pin 32 on Atmega32.

Although all the things above still stand, i.e. something wrong with your MegaDrum which causes it to send machine gun with gain settings higher than 2, your feedback made me to look deeper and I must admit there was a problem with fast drum rolls! It turned out to be due to incorrect LCD handling.

Aha! I think I see the problem now. From the first diptrace schematic I downloaded, the R19 and R20 resistor values are reversed compared to the png version displayed on the schematics portion of the site. I will compare the other components to see if there are other discrepancies.

I will try your suggestions again and report back my results. Thanks!

Edit: Also found that R9-R16 was changed from 6k8 to 4k7. Should I follow that or can I leave them at 6k8?

Besides finding out why you're not able to set gains higher than 2, you also have to upload into your MegaDrum the latest firmware. Thanks for your useful feedback!

[estregan]

Thanks! Although I somehow feel that I'm the one causing problems , I know that I'm also somehow contributing to some of MegaDrum's advancement. Cheers!

[dmitri]

Thanks! Although I somehow feel that I'm the one causing problems , I know that I'm also somehow contributing to some of MegaDrum's advancement. Cheers!

C'mon, estregan, tell us that MegaDrum failed terribly!:) Or it is so so but not as good e.g. E-drum, Alesis (God forbid mentioning Roland).

[estregan]

Hi Synthex/Dmitri,

I received my new PIC18LF2550 and tried to program them using your instructions. Again, I'm receiving failed messages in similar to what I encountered with my previous PIC18F2550.

We have even made new boards and discarded the old boards to make sure were doing it right this time. We checked for shorts and open circuits but there appears to be no errors.

What could we be doing wrong? Please help!

[dmitri]

Is it getting hot again?

[estregan]

Nope, not getting hot anymore but I still can't measure +3.3V from pin 14 of PIC and digital board ground when USB is connected.

[dmitri]

Whithout connecting to USB and without IC in the socket what is the resistance between:
1) Ground (pin 8) and pins 1, 14, 19, 20?
2) VCC (pin 20) and pins 1, 14?

With USB connected what voltages does it show on pins 1, 8, 14, 19, 20 with and without IC in the socket?

[estregan]

Whithout connecting to USB and without IC in the socket what is the resistance between:
1) Ground (pin 8) and pins 1, 14, 19, 20?

Resistance is indefinitely high on all except for pin 19 where resistance is zero (0).

2) VCC (pin 20) and pins 1, 14?

Resistance between pin 20 and pin 1 is about 3.3k while between pin 20 and pin 14, resistance is indefinitely high.

With USB connected what voltages does it show on pins 1, 8, 14, 19, 20 with and without IC in the socket?

I don't understand...which other pin do I measure the voltage with pin 1, 8, 14, 19, and 20?

[dmitri]

With USB connected what voltages does it show on pins 1, 8, 14, 19, 20 with and without IC in the socket?

I don't understand...which other pin do I measure the voltage with pin 1, 8, 14, 19, and 20?

Measure voltages between USB socket ground pin and these pins.