Let's Make Robots!

input

Uber cheap build idea, needing input...

I'm looking to build an uber-cheap robot arm, with the purpose of just sitting on my desk and picking up whatever i want it to... Probably stick with a basic control (independent forward, off, reverse switches on each motor) setup. What i'm trying to figure out is, I'm planning on using a standard 3 wire (forward, ground, reverse) style motor similar to that found in a cheap rc car, yet i can't find any places to buy them, except in the cars. any sugestions?

Shared microcontroller pin

A quick search here did not give me any relevant hits. So, I was hoping to ask the electronic gurus here if my plan/idea will work.

My thinking is that the photoresistor will be able to be read by the analog input and, because of the diode, the LED will not light unless the microcontroller is set as an output and set LOW.

EDIT:

Based on the input so far, I have redrawn the circuit. I hope the collective doesn't mind helping me get circuits straight.

Use the reset button on the Arduino as an input button
Using a
Have you ever written a simple Arduino application that just needed a single button? Most Arduino's and their clones have a reset button. Depending on your … Read more

Not all Arduino pins default to input!

Every now and then I come across a problem that takes a long time to solve. When I find the solution it is usually something very simple. I hope this will save someone else some time.

Today I am writting a program for testing the Spider controller. Since all the I/O pins connect directly to the processor there is not much that can go wrong. Basically the program just needs to check for short circuits and open circuits due to bad soldering or faults in the PCB.

Charlieplexing for sensors, is it possible?

I was wondering if it would be possible to use charlieplexing as a way to select sensors. If so, what is the minimum number of pins required for charlieplexing to work?

SRF05 with common in/out pin

I'm trying to get the PICAXE-28x1 to work with the SRF05 usnig a common input and output pin. The reason is I want to conserve my input and output pins. I've seen discussions on this site about it, but I don't know if anyone ever succeded.

Since the 28x1 allows you to reconfigure digital inputs as digital outputs, I figured it should be possible to use "Mode 2" of the SRF05 with a commmon single input and output.

Here's the code I tried. I also tried some varations the timing, as noted.  No luck so far.

PWMOUT only on two output, that are really inputs?

Am I reading the manual (section 2, page 128) correctly? Can I only use the PWMOUT on 2 specific ports on my 28X1?

This would mean that I can't run more than two outputs with pwm, and that has to be the digital in/outs 1 and 2, so there's no hope of running it through the onboard L293D??

I must have missed something, surely there is a way around this. Pulsout maybe? I'm R'ing T. F'ing M. now, but if somebody already knows the answer, that would be helpful..

 

 


EDIT: