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Showing posts with the label co-processing

April maker challenge 11- IRduino

I like the Arduino as a simple computing platform, but I've mentioned here before that I'd like to offload some of the more basic functions to a co-processor to let the Arduino have more CPU cycles for other stuff. That's true for many, MANY tasks, and one of the ones I've been fascinated with since college is the capturing and parsing of data from an infrared remote control. Adding IR to your project is a SUPERB way to add very complex I/O. I'm not sure if the Arduino has a library to read IR from remote controls, nor do I care, because it's likely to suck up an unacceptable number of CPU cycles. Thus, the IRduino: a shield with a small microprocessor (I'll probably use a PIC, since I know how to work those much better than AVRs) which decodes the signals from infrared remotes, packs it into three or four bytes (there are actually a LOT of possible codes out there, due to the number of encoding schemes). There would then be several options for sending t...

April Maker challenge 3- Tamiya servo conversion

Tamiya is a Japanese company that makes many hobby-type products- model kits, "experiment" sets, RC toys, and others. Deeply buried in their product line is a set of generic motor/gearbox combinations. These range from very simple to very complex; I have a couple of their high-power ones, and one of the 6-speed ones as well. They are well constructed, fairly tightly toleranced, and loaded with features. The have a twin-axis gearbox, a worm drive gearbox, and a planetary gearbox, in addition to more "standard" types. Typical cost is between $10 and $20, depending on the model. One of the most enjoyable items in the hobbyist robotics arsenal is the RC servo. However, most servo motors tend to be either pricey or weak, and they tend to be non-reconfigurable, meaning that you can't readily trade off speed for torque or vice-versa. To that end, I'd like to make a small PCB that would let me take an input from a shaftless potentiometer attached to the output ...

April Maker challenge 2- servo driver IC

Lately I've become obsessed with multiprocessing solutions for hobby level embedded systems. A PIC12F683 is a reasonably powerful 8-bit microcontroller in an 8-pin package, and it sells for right around $1 in qty 25. This can provide a powerful means for offloading certain functions of a circuit to another IC at minimal cost, allowing you to do heavier lifting in your main circuit than you otherwise might have. An example is servo-motor control with the Arduino. It's quite do-able, but you may find yourself in a project where you want to control a servo's rotational position based on user input from a potentiometer. In that case, using precious CPU cycles from the Arduino in the system just to read the pot and update the servo periodically is a drag. So why not take an 8-pin PIC and make a simple IC that reads digital inputs and converts the value to a servo angle? It'd be easy enough- the servo output is a PWM signal but the duty cycle is low. The motor holds po...