Society of Robots - Robot Forum

General Misc => Misc => Topic started by: Razor Concepts on November 05, 2008, 08:33:08 PM

Title: My $50 Robot(s)
Post by: Razor Concepts on November 05, 2008, 08:33:08 PM

With much help from airman00 I built my $50 robot with the mega168, I didnt want to bother with the photoresistor stuff so I made a wall follower. Will post videos later.

(http://img407.imageshack.us/img407/9754/robot001zm2.jpg)
(http://img407.imageshack.us/img407/8484/robot002ho7.jpg)
(http://img503.imageshack.us/img503/7601/robot003cs2.jpg)
(http://img407.imageshack.us/img407/4617/robot004vk0.jpg)
(http://img503.imageshack.us/img503/7738/robot005aq0.jpg)

I like how the MCU board only costs about $6 to build, so I can go crazy making different boards and stuff.

Anyways after building that I decided to build a tiny board with a attiny25. Here it is, just finished it tonight:
(http://img503.imageshack.us/img503/7494/tiny001jy4.jpg)
(http://img407.imageshack.us/img407/6868/tiny002po7.jpg)

Only 6 I/O pins, but should work with small stuff and other non-robotic projects (LED driver, RC failsafe, etc).

By the way, is a 5v regulator needed when using a 4 cell NiCd battery? Right now for the $50 board my battery goes through the voltage regulator, but to save space on the tiny25 board I didn't bother with any. Also, will it be alright if I have things like servos or sensors plugged into the ports used for programming? For example say I have a sharp sensor plugged into port PB4. PB4 connects to one of the 6 ISP programming pins. Is it alright if I leave the sharp sensor plugged in, and program using the AVR ISP?

Title: Re: My $50 Robot(s)
Post by: airman00 on November 05, 2008, 08:43:30 PM

you finally found a use for AOL CDs  :P

4 Cell rechargeable is 4.8V while a regular 5V regulator needs at least 7V to operate properly and a low dropout regulator needs 6V.

Depending on how much current the stuff connected draw , then you should pull it out. Small things like a sharp IR would not affect it but I think servos might draw voltage from the ISP programmer(which is bad)

Title: Re: My $50 Robot(s)
Post by: izaktj on November 05, 2008, 10:09:31 PM

Nice and clean robots  :D

Title: Re: My $50 Robot(s)
Post by: Admin on November 08, 2008, 11:20:31 AM

Quote

PB4 connects to one of the 6 ISP programming pins. Is it alright if I leave the sharp sensor plugged in, and program using the AVR ISP?

Nope, you'll damage something. If one device says 5V and the other device says 0V, you end up with a short.