New, need help please

Support Robots
1

I recieved an already assembled 3PI as a gift and I am using the WinAVR-20090313 library under AVR Studio 4 (ver 4.18) for programming. I have executed the BlinkLED test program and played around with simulation in the AVR Studio. I want to learn more about the architecture of the ATmega328P and the sensors and motors on the 3PI before I load up the basic line following program and start ‘tweaking’ it. Towards that end I would like to load up the 3pi-demo-program and play around with that code first. However I have not been able to locate it on the Pololu website or in the WinAVR library. Would someone please pass me a link to where I can get it?

On another note I notice that the green LED connected to PD7 is on dimly all the time - even when I have erased the program memory. When I modified the BlinkLED program to turn it on instead of the red LED I noticed that it wasn’t as bright as the red one. I don’t know if it was like this from out of the box or if it is something I have done. In fact it was so dim that I didn’t know it was on until someone else pointed it out to me. (My eyesight isn’t the best and I probably saw it, but thought it was a shiny solder pad reflecting the ceiling light.)

Sorry, for the long post and I appreciate any help you can give.

Thanks,
Steve

2

Hello,

The demo program is included with the Pololu AVR Library download, in the examples folder. We include a precompiled hex file as well as the entire source code.

The green LED is on a line that is shared with the LCD, so it could be slightly pulled up by the LCD, and you will definitely notice flickering when printing messages to the screen. LEDs are very efficient, and your eyes are sensitive to a very wide range of light levels, so you can probably see it glowing even when 1/1000th of the current is actually flowing. As for the red LED looking brighter, that probably does not mean too much: the brightness depends both on how your eyes react to the different colors and how efficient the different LEDs are.

-Paul

3

Thanks Paul, I found it. I was looking in all the wrong places (hmm, could be a song in there some place :slight_smile: ).
I appreciate the quick response and all the great info on this forum - you guys rock!

Steve