Standalone Atmega328P w/ 2 tlc5940

Other Hardware 3rd Party Boards
1

Hello

I am using a standalone atmega328p with the crystal and such set up like this http://tlc5940arduino.googlecode.com/svn/wiki/images/breadboard-arduino-tlc5940.png

although my 328P isn't on the arduino, I'm using the whole circuit like that but powered from a 3.7V LiPo battery although i get a really weird animation. I'm using the fades example from the TLC5940 library along with putting 5v into the analog.

I took a video although i'm having trouble getting it on the computer. Bluetooth wont connect. Anyway, the weird animation is that the bottem 16 leds run just fine but the top 16 flash like crazy, very random. Although they are all doing their thing at once or they are all off.

Any help?

2

3.7v? when you say standalone? like you just have a breadboard/barebones set-up?

Is that enough to power your Arduino even?

What crystal are you using? @ 3.3v volts.. I think you can only run @ 8Mhz?.....no?

maybe try another battery pack for 7.4v..etc

3

Standalone as in its just the atmega on the board. I have a crystal and the 2 capacitors.

I know that this should be working, I've had a few guys tell me that they've done this while they wire it up in parallel.

4

I think your problem is either withthe low voltage.. and/or the board setting you use using the burn.

what crystal are you using? an external 16Mhz?

if you want to try the 3.7v I would try to use a bootloader the uses the intneral 8Mhz clock @ your 3.7v..

5

Yes i've got an external 16 mhz crystal. I think i may have the wrong bootloader, since i couldn't get a sync on the chip unless I added a crystal and the 2 caps.
Is it possible to burn over bootloader that is already burned on the chip?

6

I believe so...

but did a bootloader even take?

also that link you provided shows a real Arduino board (not standalone) with some shift register chips?

not sure what that has to do with a standalone Arduino circuit you are trying to bootload

Have you tried with a 5v+ or higher power supply? or still refusing to think thats the problem?

7

I had same problem with standalone Arduino and programming at 3,3v

http://arduino.cc/forum/index.php/topic,98646.0.html

Solution: use 5v during programming, and the you can use your LiPo afterwards

8

I use the 5v during programming. 5v come out of the usb and i connect the breadboard and such to the 5V off the arduino whilst i'm programming. Its only when i pull that out and use the LiPo battery do I get the flicker in the 2nd set of 16. Do I need to program the arduino for 3.3v usage?

9

YES!

I believe you do...

When you go to TOOLS >>> BOARDS >>>

Do you see those options?

Try to pick one that matches what you want to do.

5v @ 16Mhz
3.3v @ 8Mhz..

etc..etc..

Maybe do a search on the specific settings for setting up a board for 3.3v & internal 8Mhz

10

Thanks alot! will do!