SparkFun Forums

[PrototypeNL]

Hi all,

I am thinking about slapping an arduino (or bare atmel chip) on a r/c car, and need a way to make it aware of its surroundings. The problem with that is that can not seem to be able to find cheap sensors that do the job, like infrared proximity sensors (the sharp sensors are way too expensive, i'm sure there are cheaper alternatives out there) and encoder ish things to know the position or at least count full rotations of wheels. Hall effect sensors are not going to cut it since the cheap r/c cars have plastic gears and mounting metal ones is a pain with the wheels glued to the axles.

Any chance of cheap sensors like that being sold here at sparkfun somewhere in the future?

- a robotics noob (but not for long, MUAHAHAHAHA )

[marcovansteen]

'aware of its surroundings' --> that sounds like you want the sensor to give some info to prevent or detect crashes and stuff. Cheap options to do just that are 1. mechanical switches, 2. diy infrared circuits (<E10,-), 3. diy ultrasound (<E15,-). The readymade solutions (for noobs and software guys ) are available at twice or thrice the price.

The other options you mention, like hall sensors and encoders, don't tell much about the surroundings (until crashed, that is). You could check the 'infrared sensors' section on sparkfun for some inspiration. And read this http://www.geology.smu.edu/~dpa-www/rob ... oders.html .

Groeten en veel plezier,
Marco

[PrototypeNL]

thanks for the info!
i'm going to look into diy infrared sensors and come up with something to count wheel rotations and sense steering position without using lots of moving, thus wearing, parts. maybe infrared too.

[Philba]

check out all the robotics sites - you seem to be looking for exactly what people use in building robots.

[Cyclop]

You can print a pattern of black and white alternating boxes in what ever arrangement you need and use a inexpensive IR/detector pairs available on the market. These devices are used to detect presence of paper or other objects at very short range.

Cyclop