NerdKits - electronics education for a digital generation

You are not logged in. [log in]

NEW: Learning electronics? Ask your questions on the new Electronics Questions & Answers site hosted by CircuitLab.

Support Forum » LCD 1st and 3rd row lit up.

January 21, 2011
by Anirudha
Anirudha's Avatar

Well, I am still stuck at setting up the kit. I read this thread and figured my MCU might be in programming mode, coz earlier I had a wired everything wrong(counting problem). http://www.nerdkits.com/forum/thread/998/

I have posted two images where first is the wrong wiring one and second one is rightly wired( guess so ). I am still getting the same output on LCD. How to remove MCU from programming mode, I tried powering it up and down.

AltTExt AltText

January 21, 2011
by mongo
mongo's Avatar

One suggestion... The pink plastic bubble wrap is conductive. It is designed to protect from static and has the capability of messing up the circuitry if it comes into contact with it.

From what I see, the kit should work fine. It's a little difficult to follow the wires but it looks like they go to the right places. You might want to double check just to make sure.

You can compare to a couple of examples in the "Mounting the Nerd Kit" thread at this link. One of them is mine too.

January 21, 2011
by Anirudha
Anirudha's Avatar

Thanks for your reply.... I removed the plastic, but still it has the same output. I am attaching a more clear picture of it now. One thing I wanted to ask was when I did the wrong circuitry, would it have erased the program from the MCU, or blow it up. Are there any ways to check for it. AltText

January 22, 2011
by Rick_S
Rick_S's Avatar

What are you using for power? It doesn't appear to be the 9v battery. If it is an AC-DC wall adapter, you may be getting noise into your circuit preventing it from functioning. It is not uncommon to need to add a small (10uf - 100uf) capacitor to the power rails right at the regulator to smooth the power out when using a wall adapter. If you don't have a capacitor, try a fresh 9v battery at the regulator in place of the wall adapter to see if that works.

I didn't see any posts from you in the link you listed, however, when you say you wired everything wrong (couning problem), were you saying you had all the wires to the micro and LCD off by 1 position? Because running 5v into the gnd pin of the chip would not be good for it and could have damaged it. However, if your power connections to the micro were correct and the LCD was just connected incorrectly, most likley things would be ok.

I also agree with mongo, the wiring looks correct.

Rick

January 22, 2011
by Ralphxyz
Ralphxyz's Avatar

What OS are you using?

Unplug the USB and/or reboot.

On my MACmini the yellow usb wire has 2.5v which "sometimes" keeps the mcu in a zombie state unless interrupted (unplug usb).

Ralph

January 22, 2011
by Anirudha
Anirudha's Avatar

Rick, I tried putting up a battery, but it still gave me the same output. And about wrong wiring, I meant was all of it, not just MCU to LCD. If I have damaged the MCU isn't there any way to check for it ???

January 22, 2011
by Anirudha
Anirudha's Avatar

Ralph, I am still stuck at the first project ever, of just wiring it up, far away are programming it.

January 22, 2011
by Rick_S
Rick_S's Avatar

If you had the power wires reversed to the micro, or even ran the 5v rail into the micro's ground, with the ground rail connected elsewhere, you could have permanantly damaged the micro. The only real way to tell, since it appears your wiring is correct, would be to order a replacement micro. I would guess the LCD is trying to work as the two black bars are normal for it when it is on but no data coming in.

Rick

January 22, 2011
by Anirudha
Anirudha's Avatar

Thanks Rick, guess I blew up the MCU, well I can't order another one(I don't live in America, international shipping with customs in my country is quite a pain). Still let's see if anything else might work out.

January 22, 2011
by Ralphxyz
Ralphxyz's Avatar

You do not have to be programming it, just try removing the USB and rebooting.

I have often placed the mcu one pin off and powered it up with out doing any damage.

So I have had + voltage to the - pins and - to + pins with out damaging the mcu.

Of course I have also blown one and a LCD but not from hitting the pins wrong.

Ralph

January 22, 2011
by Rick_S
Rick_S's Avatar

Ralph, I may be wrong, but I don't think he had the USB connected, he didn't have it shown in any of the photo's.

You've been lucky at not blowing the micro's, I haven't been as fortunate. I've blown two. One, because I acidenttaly shorted 12V to one of my output pins, and another because I had the ground and power reversed on the ADC side. Both chips still did some stuff but it killed other parts. The 12V shorted one lost that output pin, the other lost the ADC. So while I wish I had your luck, it doesn't always go that way...

Anirudha, do you have any online electronic stores in your country? You could order a blank micro and an ISP programmer to set a chip up yourself. The steps aren't that difficult if you can get the parts. An ISP programmer would also give you an alternate method to check the programming in the micro you currently have.

Rick

January 22, 2011
by Ralphxyz
Ralphxyz's Avatar

Ok, Aniudha are you sure the mcu is firmly inserted into the breadboard?

You will get the two black bars if there is no mcu so make sure it all the way in.

When the breadboard is new you have to be firm with it.

Ralph

January 22, 2011
by haaser
haaser's Avatar

Here is a suggestion I do not know if it is a good one but anyway. Could you not put the USB cable on the breadboard and try to flash the MCU via your computer. I assume that if it is still good it should take a program? Also what happens with a MCU has a corrupted program does it go blank or will it default to programming mode? What output does a blank MCU put to the screen?

January 22, 2011
by Anirudha
Anirudha's Avatar

Rick ,Thanks, I will look for that.

January 22, 2011
by Anirudha
Anirudha's Avatar

Ralph, thanks for the suggestion, but I have checked their connectivity, from output pins of regulator to VCC pins of MCU, MCU to LCD and every pin, like 10 -15 times now. It all works out good. But still the damn LCD isn't giving me the output.

January 23, 2011
by Rick_S
Rick_S's Avatar

Anirudha, I don't know if you have tried what haaser said, but it wouldn't hurt. As Ralph said, there is a chance your micro may be functional, he has had good luck with that, and you may as well. If your micro is still alive, haaser had a good point, because if the actual program was corrupted, you won't get a display. If the bootloader is still on the micro, and the micro is still functioning, you could load the initialload program and then should see the display come to life.

For that matter, as rare as it may be, you may have a micro that was never programmed. If that is the case, you would never be able to program it or see anything on the display with what is provided in the kit. I don't know how good you are at electronics, or if your pc has a true parallel port or not. However, if trying to re-program doesn't work, if you are good with electronics, you could try building a simple ISP programmer that would connect directly to your pc's parallel port. They can often be built from spare parts you may have lying around for little to no money. Then you could program the micro via ISP and install a bootloader, or upload a program. This would be the final method of determining if your micro is still alive.

Hack-a-day has a pretty good write up of different methods of ISP programming an AVR one of which is the parallel port (Called DAPA) programmer. They provide a basic schematic for the programmer there as well as instructions for use. If you search the web for DAPA AVR Programmer, you will find a lot of other resources as well.

On a last note,

I want to apologize to Ralph if I came off poorly yesterday. Ralph is a great guy and a wonderful asset to the forum. I on the other hand have little tact at times and after re-reading my posts, I am ashamed of the way I spoke. Ralph, if you read this please accept my apology.

Rick

January 23, 2011
by Anirudha
Anirudha's Avatar

Hey, thanks Rick, really thanks. Well, I wouldn't like to boast but I am an undergrad in Computer field but do have a pretty good electronics side too. I am gonna try that. Thanks again, you're great.

January 23, 2011
by hevans
(NerdKits Staff)

hevans's Avatar

Hi Anirudha,

Quick thing to try. As part of the preloaded program we put on we toggle a pin on and off momentarily. Take one of the LEDs in your bag, put the anode on Pin 27 of the MCU, and the cathode on the GND rail. Then reset power to the chip. Our preloaded code blinks this pin on and off once, so you should see the LED blink momentarily when you turn the chip on. If it does it means your chip is on and alive, and there is an issue with the LCD. If it does not blink it means that you probably damaged your chip, when wiring it wrong. I would keep going and try to program, it is possible that the user program was corrupted but the bootloader is fine, which means you will be able to program it. If you get errors during programming then your chip is dead. In that case send me an email and we will see what we can do to get you up and running.

Humberto

January 23, 2011
by Ralphxyz
Ralphxyz's Avatar

Rick, you really were not that objectionable. In fact you made some valid points.

I on the other hand had not noticed that there were no USB wires.

So feel free to let it rip. Don't let your fear of my sensitivity hold you back, your answers and projects help me so much. I really appreciate your contributions, you are what makes the NerdKit forum so great. Which as I have said before is the primary reason I purchased the NerdKit instead of going another route.

Anirudha, I would suggest that you completely strip the bread board and start from scratch.

Or at the least remove the mcu and reinsert it. But I like starting from scratch.

I have done that a coupe of times to clear problems. This has not been "scientifically" established but "sometimes" there appears to be a capacitive charge induced on the mcu breadboard, like I said before I have problems with my MAC mini USB causing the mcu to not shut off so it is always charged (on) unless I interrupt the yellow wire. I do not get this situation from Windows7.

It would be interesting to know if you did actually blow the mcu so please keep us posted.

Ralph

January 24, 2011
by Anirudha
Anirudha's Avatar

Hey, Humberto, nice trick to check stuff, well I am sorry to say, it aint working. Guess the chip is blown, i'll try program the chip let's see what errors pop up.

Hey Ralph, i tired that already like 4-5 times, no changes. :-(

January 25, 2011
by Anirudha
Anirudha's Avatar

Hey, I tried 'make'ing the initialload program but I get this error , butterfly_recv() : Programmer is not responding. I searched the forum and found this link (http://www.nerdkits.com/forum/thread/47/) , where you said it might be the wiring problem to the lCD, I guess the LCD might be the not working. I have attached a image of the connections, I don't know if this should be the case, but the LCD in programming mode shows the 2 rows, and don't know how this happened but it's contrast has reduced, I did not change resistor, I tried a different one but of same value. alttext

January 25, 2011
by Ralphxyz
Ralphxyz's Avatar

Anirudha, does the initial load program run or are you still stuck with the two black bars while in run mode?

Just for the record and if anyone else is having the problem of the mcu not going into run mode.

The other day one of my mcu's stop running, it always showed the two black bars (rows 1 and three) on the LCD.

I re-loaded the bootloader half a dozen times and I loaded various programs to no avail, I always got the two black bars.

That was two days ago, today I thought I'd try again and I got the same results.

Then I looked at the chip and saw that pin 14 had gotten flattened out it was not making any contact at all but nothing was complaining so I had assumed everything was correct.

So lesson for the wise if you always/only get two black bars check your pins!

Ralph

January 25, 2011
by Anirudha
Anirudha's Avatar

No Ralph, I am still stuck at run mode showing two black bars, one more thing is when I try to run initialload, i get error, mentioned above. I checked their continuity, none of them seem 'flattened' .

January 25, 2011
by hevans
(NerdKits Staff)

hevans's Avatar

Hi Anirudha,

Seems like you have tried everything and your setup still isn't working. My bet is that you managed to damaged the MCU during when you plugged the power connections in wrong the first couple of times. Send us an email at our support email address and I'll see what we can do about getting you up and running again.

Humberto

Post a Reply

Please log in to post a reply.

Did you know that a microcontroller can measure an RC time constant? Learn more...