Let's Make Robots!
Price: $44.99 USD

 Collected by one member
Create your own toys, remote controllers, alarms, detectors, robots, and many other projects with the Arduino device. Read more

Dual Cell Lipo Charging IC

Hey guys,

Can anyone suggest an IC that could be used to charge dual cell Lipo batteries (7.4V) with cell balancing? Ideally the IC would be powerful enough that it could charge even if the system is under a light load. I am looking for something similar to
the MAX 1555 IC (http://www.sparkfun.com/products/674) but for multiple cells. My google search has been fruitless - I must be using the wrong keywords. Thanks for any help!

My intro and a request for pointers for navigation pseudocode please.

Hello All

I am new here and am currently working on building my first robot. I think I bit off a larger project than I ever should have for a first bot, but have learned a load in the process.

I built a RepRap 3D printer and have since printed out some track links and wheels (a design I found on thingiverse). I have designed my own chasis and am currently on version 4 which seems to be fairly stable.

My bot is a catarpillar..

Price: $21.95 USD

 Collected by one member
FreeM is a wireless Infrared I2C controller for completely stand-alone programming and control of BlinkM smart LEDs. It's like an invisible wire linking a Remote, a … Read more
Price: $10.5 USD

 Collected by one member
The Adafruit LCD backpacks reduce the number of pins needed to connect to an LCD. LCDs are a fun and easy way to have your microcontroller project talk back to … Read more

Transistor terminal naming conventions.

I am trying to figure out how transistors work and have seen the three terminals on a bipolar transistor labelled base, collector, and emitter.

I am having a hard time understanding the purpose of the three, and would like it if someone could explain why they are named this way. I.e. what is basey about the base and what is the collector collecting?

At the moment they just look like three randomly chosen words.

Thanks

Price: $7.95 USD

 Collected by one member
Patented technology by Spectra Symbol - they claim these sensors were used in the original Nintendo Power Glove. I love the Nintendo Power Glove. It's so bad! Read more

REPLACING PICAXE PROGRAMMER CABLE ?

 

 

I hope you may give me advice on the following subject:

 

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Best way to Power an 8 servo - Quadbot

Hi. I want to power a Dagu Qadbot without sources, only batteries, but don't know the best way to Do it. It uses 8 micro servo - 8g, 4~6V, and draw a current that I don't know the specific value as I didn't find a Datasheet.

 

So, as I'm almost sure that only Arduino will not be able to power the 8 servos, I'm thinking about 2 solutions:

 

1st - Use 4AA Battery to power - the Arduino i parallel with the servos. This way I'd power the servos directly and just connect the digital pin to the arduino. 

Why won't it vark?

I've made a development bot named Arcee as some of you know, now i've added an AmandaLDR to it for obstacle avoiding.The LEDs on the sensor are very bright and blue in colour. The bot won't use a servo to pan the sensor, it'll simply rotate itself.

The problem is, I don't think it's working. But the sensor works, oddly enough. It can turn an LED on at a threshold. But once implemented into an obstacle avoidance code it dosen't seem to work.

The code is attached below.

 

 

I built TrackBot a test platform for various technologies. It's easy to add sensors and servos. I'm using it to prototype the desgin of B4, a BeagleBoard based … Read more

Can a 3,4V solar panel charge a 3,6V NiMH battery pack?

Can a 3,4V (open circuit voltage) solar panel charge a 3,6V NiMH battery pack?

Homemade Filter Fan Distraction

Introduction

I was crusing YouTube and saw a few videos on these homemade filter fans from Altoid tins.  I don't have a fan system since I usually just do my building on the kitchen bar area, so I thought this would be a good idea to build.  After watching these videos and finding out that it was some article in Make magazine, I breadboarded the circuit and wrote down the diagram for the project.

The Filter Box

Why would you buy anything from Sparkfun?

Just to be able to serve you better in future LMR shop, I'd like to get any random thoughts'n inputs to why you might shop at Sparkfun instead of the LMR shop we are building?

Please don't hold back - we need to know where the sore points are, thanks :)