Let's Make Robots!

hacking toys

hey all,

i'm trying to take apart a bunch of toys and other small electronics. They all have a push-button that mashes down on the PCB to operate. the spot underneath the button looks like this: (forgive the hasty visual):delete-me.gif

I think that the push of the button connects the two. So my question, then:

What's the best way to get "electronic-ize" this so my IC can do it?


-solder them together and turn the power on/off via my IC?

The new Picaxe bug?

Consider this test code for Picaxe.

high 5
for w0 = 1 to 65535 next w0
high 6
for w0 = 0 to 65535 next w0
high 7

Please feed it to your Picaxe, whatever breed. Change the directive #picaxe.... accordingly or remove it. The directive #no_data just speeds up the program load.

Now tell me, how long does it take for the ports to go high (for the LEDs to light up)?

Powering Arduino and servos/motors with one supply

Helo, all

I tried to power Arduino (Duemilianove) and servos/motors it controlled with the same battery, but Arduino continuously restarted during the operation. Actually it was a surprise for me, since Arduino already has voltage regulator chip and filtering capacitors in the input circuits...

I solve this problem by supplying them with different batteries, but I don't like this solution. Could anyone help - how to provide single power supply?

what IR sensors can the picaxe take?

its no big deal!!

but i'm not sure if the picaxe can use a "Sharp GP2Y0A02YK Sensor"

like the one from this site:  http://www.active-robots.com/products/sensors/sensors-sharp.shtml

also please tell me if you know other good sesors for a picaxe from this site!

Full size Johnny Five

The best spot I've found for every detail about building your own J5



I dont know how to u se it or what it can do but can i use it in any way.

It was found in a old DVD player that the laser was failing so I took it apart.

Any info maybe how i could program it / use it would be very helpful.

thank you 


Modding a servo

I am planning my first "robot", if you would call it that =p. I know you can mod a servo for continuous rotation, but I was wondering if you can mod a servo for less rotation, like 90degrees for example.

Thanks for your help

9v battery in a picaxe


i plan to install a micro spy-cam inside my quadropod(SC-QR-1)

ive allready got the cam and it uses a 9volt battery to power it!

a problem is that the 4 AA batteries inside takes all the extra space inside, but if i took another 9volt battery with some kind of converter that makes 9 into 6 volt to power my robot!

the question now is: 

what should i use?

 please tell me what, where to buy, and the price of it! =D

EDIT: do you think something from these sites might be usefull?:

Animatronic NIN

Uh, yeah. Nothing like taking a happy fun memory and turning it to Nine Inch Nails :

FYI, the Rockafire Explosion was an animatronic band that played in a kids pizza chain, Showbiz Pizza, in the 80s. Kooky, happy, family songs, played Beatles Happy Birthday song for kids, etc. Now only in collectors and inventors hands. 

And now, after the Showbiz's have closed, this.  Wonder if they'll cover Pantera?

Help with 555 circuit.

Well, I have got the 38khz distance sensor working in picaxe form.



Now I am trying to wire-up a stand-alone unit with a 556. Now I know this is a RTF(data sheet) moment and I know the resistor/resistor*cap/2 (or whatever) equation, but the final circuit is still above my head. Are there any of you circuit guys out there that can do a little drawing for me? Maybe with a couple pots for fine adjustment? I plan on the final output going into a picaxe using the pulse-in command.

Thanks in advance.

SparkFun order compilation

Well i've been saving up for another sparkfun order for a while. At the moment i only have a 28x1 w/ project board, one l293d, two motors, a sharp and a ping. Today i recieved two GM2s with some wheels and two more L293D's but i dont have another chip to use them with. Point and case i need some help picking up new parts.

How many PIC users here

I was wondering how many PIC users are on LMR and what languages are being used.  I am currently a fan of the dsPIC33's and use C and assembly for programming.

PCB Fabrication

I just discovered this site http://www.pcb-pool.com in the new Servo magazine. I went to check it out and was surprised. I can order 100 PCB boards of my shield design for $330 with 8 day turn around. SparkFuns batchPCB which is what I have been using would cost 1445.95 for 100 of the same board, and they take about a month to arrive.

picaxe or arduino automated ball pick up?

I have a picaxe and an Arduino, I'm trying to make a robot that scans for a golf ball, picks it up, then returns it to me, I found the CMUcam, but it is very expensive, is there an easy way to do this task? Am I overthinking this?



thanks :)

Beginner here. I need some direction...

I have come to a point in my life where I have some free time for a new hobby and I think robotics is something I could enjoy.

As I understand it, the following seems to be the basic skillset necessary to really get into robotics:

-  ability to understand and create mechanical features with your hands

-  have an understanding of electrical circuitry (especially in the context of commonly used robotics components)

-  have an understanding of event driven computer programming

Accurate temperature reading


Sorry if this post is in the wrong place but I don't know where it should really go?

Does anyone know if there is a piece of hardware that I can connect to an Arduino that will give me an accurate temperature reading. 

Are thermistorsaccurateenough to get a reading from?

Thanks in advance,


12vdc 5 Relay Board - WHO want IT!

Hi LMR's

I giving a way 2 of this nice 10 relay boards. Salvaged from working a control system to be discarted.

They are 12 vdc coils drived by 2 ULN2004, also have indicator power led and filter in the OUTs.

The board measures about  3.25 x 4.0 inches.

I hope that 2 of you people can use them.


Update------- They are SPST, one make by relay.


darlington drivers

Hey all.

Calculon has a question about the uln2803 darlington driver. He has a datasheet that says "the darlington pairs may be connected in paralell for more current-carrying capacity."   Calculon wonders how this is done?

Would that be pair of darlington pairs? And if he wanted more current capacity than that, what transistors would he use to make his own d-pair?

Calculon thanks you.

Soldering station...

Is there a particular rated (power) soldering station that I should look to buy?  Also - what tempreature should I usually run it at for day to day use?

Thanks in advance,


Remote control thing

I really dont know what the exact definition of a robot is...(Being autonomisnous*) but i am going to attempt to make a 4 wheeled remote control hybrid car with AA and solor panel on top...my goal is to be as fast as i can controlling it.

Items already planning on use http://letsmakerobots.com/node/5446 ... is it any good? and are there any items/stuff that can help me or intrest me on this project...thanks for your help and hope its not too stupid of a question

what will i need? i know a source/wheels... what else/what prodects?