Let's Make Robots!


Follows Lines

This is Doris the line loving robot (she's also my first). She's simple with no brains using Light Dependant Resistors to detect the line, this has its draw backs in that she requires fine tuning for various light conditions.

Parts (*marks salvaged parts)

1x L293D IC

1x 16pin IC Socket

3x Ultra bright LEDs

1x LED (Power Indicator) *

2x BC548 Transistors

2x 20k potentiometers

1x 10uf Capacitor

2x 0.1uf Ceramic Capacitor

1x PCB AAA Battery Holder

1x Female Header Strip

1x Male Header Strip

2x Small Motors *

1x PCB Strip board

2x Lego Wheels *

2x 220ohm Resistors

1x Strip Board

Several Gears, Axles, and Plastic Rods *

I don't plan to improve her any as I have gone as far as I would like with her.

This is also my first post on LMR, so a big hello to all members :).


Comments welcome.


Oh and sorry about the photo quality.





































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neat and compact. fast little critter!. good job. 

#ignoblegnome I think maybe she's a little camera shy :)

#tatofoo The chassis was made using plastic salvaged from 2 flying grasshoppers I basically trimmed the frames and join them with hot glue, I then added a few cross members from the offcuts to strengthen it. I used a small carbon rod with a small blob of melted plastic on the end to keep the front of the robot off the ground. I also had to glue 4 offcuts vertically to stop the frame from bending as the wheels appeared to point inwards when moving without them.

#CaptainObvious Ill be buying some brains next pay day, I'm going with Atmel's Atmega328 and plan on using the Arduino boot loader and software. I dont really want to be stuck with the form factor or cost of the full Arduino packages, so ill also be buying a USBtinyISP kit from adafruit, and a FTDI from Farnell, to allow me to do a “poor man's duino”.

#ezekiel181 The motors were salvaged from the 2 flying grasshoppers mentioned above. A hood, how come I didn't think of that. I may go back on my word and add a hood to the front this weekend. AmandaLDR looks interesting it will come in handy in the future thanks for pointing me to it.

Nice compact look, and i'm always impressed by "non brained yet intelligent" robots!

Cool little robot. Are the motors inside also from a lego set?

To avoid having to recalibrate every time the light changes you could add a hood over the front shielding it from ambient light. You could also do it in software by turning the LEDs off, checking the LDR, turning the LEDs on and checking the LDR again. It gives you a kind of base light level to calculate in. Have a look around the site for FritsLDR.

Oh and welcome!

FYI, he renamed it AmandaLDR

Welcome to the site! :D

Awesome first bot, and I'm with Gnome on this one, scavenged parts for the win! I'm actually about to goto the local thrift store and see if I can't find any old RC cars! :P

I'm anxious to see what you'll do in the future, especially if it has brains! :P

Hey, nice robot, I like it for being compact :), how did you make the chassis?

Doris is pretty speedy. She held onto the line in the video really well until she flew off at a tangent.

Nice work for a simple bot. Doing more with less is always cool. I always appreciate some good part scavenging as well. ; j