how can I know if my mac is truly communicating with the MD?

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Re: how can I know if my mac is truly communicating with the MD?

Postby jeffbeckib » Thu Feb 05, 2009 5:11 pm

Yep, the new synthex kit with atmega32. Pic18f out of socket, holding left button while I power up, still nothing on lcd except backlight

What are the minimum requirements to get the bootloader to display something on lcd? ex. resistors,capacitors,icu's etc.
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Re: how can I know if my mac is truly communicating with the MD?

Postby dmitri » Thu Feb 05, 2009 6:22 pm

jeffbeckib wrote:Yep, the new synthex kit with atmega32. Pic18f out of socket, holding left button while I power up, still nothing on lcd except backlight

What are the minimum requirements to get the bootloader to display something on lcd? ex. resistors,capacitors,icu's etc.

1. Atmega is ok
2. Bootloader is programmed.
3. LCD is ok
4. Connection between the LCD and the bootloader is ok.
5. Power to the board is ok
6. Crystal is ok.
7. capacitors connected to the crystal are ok.
8. Buttons are ok
9. Connection between the buttons and the board is ok.
10. No breaks on the traces to pins 4-13, 16-21, 30-32 of Atmega
11. No shorts on the traces to the same pins.
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Re: how can I know if my mac is truly communicating with the MD?

Postby jeffbeckib » Thu Feb 05, 2009 6:58 pm

here's what I picked up, is this ok to use? and just to verify, am I ok to use pin 5 on the keyboard connector on the board as a ground?
What kind of readings should I expect to see?
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Re: how can I know if my mac is truly communicating with the MD?

Postby dmitri » Thu Feb 05, 2009 7:33 pm

jeffbeckib wrote:here's what I picked up, is this ok to use?

It's ok.

and just to verify, am I ok to use pin 5 on the keyboard connector on the board as a ground?

You can use any ground point as long as all of them have unbroken connection to the USB ground or power ground

What kind of readings should I expect to see?

You measure them, and I'll tell you which are correct and which are incorrect.
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Re: how can I know if my mac is truly communicating with the MD?

Postby jeffbeckib » Thu Feb 05, 2009 7:47 pm

ok I'm assuming I have to have usb power connected to power the board,
here's what I get
on pic18f2550 Im getting the following readings
pin 14 = 0 Obviously this should be 4.97, what could be the problem here??
pin 20 = 4.97

atmeta32
pin 10 = 4.96
pin 30 = 4.96
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Re: how can I know if my mac is truly communicating with the MD?

Postby dmitri » Thu Feb 05, 2009 8:11 pm

jeffbeckib wrote:ok I'm assuming I have to have usb power connected to power the board,
here's what I get
on pic18f2550 Im getting the following readings
pin 14 = 0 Obviously this should be 4.97, what could be the problem here??
pin 20 = 4.97

pin 14 should be 3.3V with pic18F in the socket. Without pic18f it should read 0.
Forget about pic18f for now, take it out of the socket. You first need to find out why Atmega or LCD (or both) is not working.

atmeta32
pin 10 = 4.96
pin 30 = 4.96

It's correct.
Measure the following:
1. Voltage on pin 9 of Atmega.
1. Voltage on pin 2 of the LCD.
2. Voltage on pin 3 of the LCD.

Disconnect from USB and measure resistance:
1. Between the ground point on the USB connector of the board and pin 11 of Atmega.
2. Between the ground point on the USB connector of the board and pin 31 of Atmega.
3. Between the ground point on the USB connector of the board and each of pins 14-21 of Atmega.
4. Between the ground point on the USB connector of the board and each of pins 6-8 of Atmega.
5. Between the ground point on the USB connector of the board and pin 1 of the LCD.
6. Between the ground point on the USB connector of the board and pin 2 of the LCD.
7. Between the ground point on the USB connector of the board and pin 3 of the LCD.
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Re: how can I know if my mac is truly communicating with the MD?

Postby jeffbeckib » Thu Feb 05, 2009 8:56 pm

atmega pin 9 = 4.73
lcd
pin 2 = 4.95
pin 3 = 2.76

Which pin is ground on the usb connector?
Which ohm should I have the meter on? I've got 2000k, 200k,20k,2000,200
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Re: how can I know if my mac is truly communicating with the MD?

Postby dmitri » Thu Feb 05, 2009 9:33 pm

jeffbeckib wrote:pin 3 = 2.76

Connect to USB again while holding the key LEFT pressed. Shorten (connect) pins 1 and 3 of the LCD, e.g. with tweezers. Be careful not to shorten to pin 2. Still nothing on the LCD?

Which pin is ground on the usb connector?

The one which has a trace going to all other ground traces/pins/points/etc. It is pin 4 according to http://pinouts.ru/Slots/USB_pinout.shtml

Which ohm should I have the meter on? I've got 2000k, 200k,20k,2000,200

2000.
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Re: how can I know if my mac is truly communicating with the MD?

Postby dmitri » Thu Feb 05, 2009 9:37 pm

I must say, you're very brave to venture soldering MegaDrum with that level of electronics skills. Please, don't be offended.
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Re: how can I know if my mac is truly communicating with the MD?

Postby jeffbeckib » Thu Feb 05, 2009 10:10 pm

When I short pin 1 and 3 on lcd I get a row of white blocks on the bottom row.



dmitri wrote:
jeffbeckib wrote:pin 3 = 2.76

Connect to USB again while holding the key LEFT pressed. Shorten (connect) pins 1 and 3 of the LCD, e.g. with tweezers. Be careful not to shorten to pin 2. Still nothing on the LCD?

Which pin is ground on the usb connector?

The one which has a trace going to all other ground traces/pins/points/etc. It is pin 4 according to http://pinouts.ru/Slots/USB_pinout.shtml

Which ohm should I have the meter on? I've got 2000k, 200k,20k,2000,200

2000.
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Posts: 183
Joined: Wed Dec 17, 2008 8:46 pm

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