Half of My LCD Lights Up

[Axaday]

I don't have the injector and VSS signals yet, but I got power and ground so that I would be able to see that my unit worked. Someone said it would, but it would just read 0 mpg.

What happened is that the right end of my LCD lit up all its pixels so that it looks like a bunch of blocks and the left end of the LCD does nothing. Obviously something needs fixing, but I'd sure appreciate a hint if someone knows where to look.

[ptsmith24]

I would double and triple check your solder connections. In addition, maybe try reflashing the mpguino software to the arduino? Hope that helps. Someone else with more experience with the unit will probably be along shortly to offer further suggestions. In fact, I'm about to build mine in the next little while.

[Axaday]

I doublechecked every solder very carefully and they are all good.

I get a little bit of current between two of the claws on the voltage regulator, but confirmed that I didn't short it. Is that normal?

Some of the pins in my iDuino seem to let some current from one pin to the next, but again I confirmed that I didn't short it. Is that normal?

What I'm beginning to believe is that my LCD is broken. I used a little superglue in putting this thing together and it corroded a little of the black frame on the LCD and I fear that this could have somehow eaten on the innards of the LCD. Maybe? I could certainly order another one.

[dcb]

Definitely try re flashing first.

[Axaday]

I actually reloaded the program before I rechecked the bazillion solders. No good.

[Yoshi]

My bet is defective LCD unit.

Ken@Japan

[Axaday]

Well, that's not such a terribly hard fix, now that I think of it. I can fix that in a few minutes when a new one arrives.

[Axaday]

I replaced my LCD and now the whole LCD lights up its blocks. I don't have the VSS or Injector signals tapped yet, but I've plugged it into power and ground and it just gives me the fully lit screen. White blocks on a blue background.

[ptsmith24]

Do you have the software flashed? If you do, it should still be giving you more than blocks. Maybe I'm missing something...

[dcb]

Ax, Have you already run through the setup screen? If not then tap the middle button a few times when you first start up and see if that helps. I've got a few other thoughts but let me know how that goes first.

Also I need to know what version of the code you have loaded.

[ptsmith24]

Also, I was getting blocks on my LCD after changing from USB to car power. Try power cycling (slowly, wait 20 seconds or so after unplugging before plugging in again). See if that helps.

[Axaday]

I appreciate everyone's help. It would be nice if I had a little more daylight time this week to work on this, but I don't. I rechecked my LCD solders this morning and they seem to be good enough and then I came over here and read the replies and took it back to the car. I plugged in and pushed some middle button and then just by chance I saw from an angle that the screen actually said "Contrast" "000000". It looks like blocks from head on. I tried to adjust it with the other buttons, but I was difficult to see what the screen said then. Whatever it said was on the other end of the LCD and I couldn't make it out. Then I pushed again and it looked like it said "VSS Signal" "100" or something like that.

So it sounds to me that maybe it is working and I just need to work on settings. It is time to go to work for another 12 hours this very minute, but I suppose that I will find a manual somewhere on the site that will tell me how to adjust contrast and get everything setup.

[ptsmith24]

To adjust the contrast, use the left and right buttons to navigate left and right through the number fields. Use the middle button to increment the number in the current underlined field. You should just hit the middle button the first time. Even if the contrast is too high, it might be readable for the next time around. Hope that helps.

[Axaday]

I can't get the contrast to respond to the buttons. Some of the pixels change a little when I press buttons, but where it says Contrast 00000000 nothing changes.

[ptsmith24]

Try grounding the appropriate pins directly (rather than using the button) to see if it's a bad button.

[dcb]

Axe, what version do you have loaded? You are using the Blue LCD from where?

I need more info to help you. But try this sequence:

Without doing or pressing anything else:
1. power up the unit
2. hit the middle button until you can read the display

Let me know if that works or not.

[Axaday]

I have the current software as of a week or so ago and I bought the blue LCD in the MPGuino main thread. Pushing the middle button doesn't do any good.

But I just found something disturbing with my multimeter. The middle button seems good, but the other two buttons are leaking electrons. I don't see a problem with the soldering, so I have to guess that these buttons are broken. Maybe the middle button isn't working because the unit thinks I'm scrolling up and down superfast?

I tested all the buttons before I put it together, so something must have damaged them somehow afterward. I can't think what.

[ptsmith24]

I'm not sure how much heat the buttons could take, but maybe too much heat during soldering? Mine took a good bit and they work fine, but I suppose it's still a possibility.

You're right; Maybe the left and right buttons are "stuck closed". Try disconnecting the left and right buttons from pins 3 and 5 and just trying the middle button (or disconnect all 3 buttons and manually ground pin 4, middle button pin).

[Axaday]

Soldering at those pins was very difficult for me. I'd rather try replacing the buttons if I can find them at Radioshack.

[ptsmith24]

How did you connect the wire from the button to the board? I have mine pushed into the appropriate pin header (nothing real permanent). In other words, can you disconnect the button from the board (but still keep the wires connected to the button itself)?