not work

[Aigars]

hi guys, maby u undertend, whats can be wrong.

[tom66]

You have several solder bridges on the board, I am not sure if they are intentional.

[Thor-Arne]

Perhaps a contrast trimmer for the LCD ?

[128er]

Perhaps a contrast trimmer for the LCD ?

At first glance i would guess the same. Make the contrast voltage adjustable. Seems like you have fixed the contrast voltage with a divider? What voltage is on (i guess) pin 3?

Schematic would also be good and code from the atmel controller.

[Balaur]

Schematic would also be good and code from the atmel controller.

It looks to be a version of the AVR Component Tester. Maybe this one.

[Neganur]

bit hard to tell but I think most of what looks like solder bridges is actually glare from the left-over flux. I'd look into a contrast trimmer too, caught myself forgetting it a couple of times

[Mr Simpleton]

What about ground... I fail to see how the groundplane in lower left is connected to the other ground?? 

[Balaur]

What about ground... I fail to see how the groundplane in lower left is connected to the other ground?? 

It looks to be connected on the left switch side (and through the switch itself)

[TerraHertz]

What about ground... I fail to see how the groundplane in lower left is connected to the other ground?? 

This. No, they're not bridged by the pushbutton.
Also, the two small diodes - what happened to them? Using thin leads as scope probe clip points is not a good idea.
Anyway they both have mangled leads, perhaps they are fractured?

Edit: Oh wait. Are those actually surface mount resistors with wires soldered to them?

[TVman]

Edit: Oh wait. Are those actually surface mount resistors with wires soldered to them?

Yes,
Yes they are...

[ajb]

I'm not seeing any breaks in the ground plane.  The area on the lower left that appears at first glance to be isolated looks to be connected by a single thermal track on one of the TO-92 pads.

There are a number of HD44780 libraries for the AVR that don't have proper initialization sequences, and may or may not properly reset any given LCD controller. 

[Aigars]

there its sam mor

[Neganur]

You need to look into using a contrast potentiometer.
That static voltage divider is doing you no good unless you know exactly what value you need for your specific display.

Þú þarft að líta inn með andstæða potentiometer.
Truflanir spennu Divider er að gera þér ekki gott nema þú vitir nákvæmlega hvaða gildi þú þarft fyrir display.

[Tac Eht Xilef]

Perhaps a contrast trimmer for the LCD ?

At first glance i would guess the same. Make the contrast voltage adjustable. Seems like you have fixed the contrast voltage with a divider? What voltage is on (i guess) pin 3?

You need to look into using a contrast potentiometer.
That static voltage divider is doing you no good unless you know exactly what value you need for your specific display.

4th'ing this. I've got a bunch of very similar looking displays from DX that are very picky about the contrast voltage, and the up/down viewing angle is terrible at best. Unless the contrast is adjusted spot on, they're unreadable.

[Aigars]

hmm, and how i can fix this?

[Aigars]

hmm, and how i can fix this?

its a 0,42volts
in 3rd

[Neganur]

I would first check if that corrects your problem by replacing R8 and R9 by a 50k potentiometer:

Remove R8 and R9 from the board you already assembled and solder a pot in like in the attached picture.

[madires]

Please replace the 7805 with a 5V MCP1702 or add an external 2.5V voltage reference (download Karl-Heinz' documentation at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ for the details).

[Aigars]

its samthing moor, its dont coming leters on the screen

[Aigars]

its samthing moor, its dont coming leters on the screen

and alsou dont make a test
maby samone can give me sett of this tipe tester. schematic ans hardware. schematic please in eagle file.
tx

[Neganur]

Are you sure that you connected the potentiometer between +5V and GND, with the wiper going to the VO pin?

[Aigars]

Are you sure that you connected the potentiometer between +5V and GND, with the wiper going to the VO pin?

yes

[Monkeh]

Are you sure that you connected the potentiometer between +5V and GND, with the wiper going to the VO pin?

yes

Then perhaps you can explain why your picture showing it not working, also clearly shows that you did not connect it correctly.

[Aigars]

Are you sure that you connected the potentiometer between +5V and GND, with the wiper going to the VO pin?

yes

Then perhaps you can explain why your picture showing it not working, also clearly shows that you did not connect it correctly.





no, its connected corect. its samthing ealse. hu can give me new plate scheme and soft. i can build new

[Monkeh]

no, its connected corect. its samthing ealse. hu can give me new plate scheme and soft. i can build new

I guess you're not interested in learning anything, then.