Let's Make Robots!

Cheap Oscilloscope

Cheap Oscilloscope now on sale for only 40$. This was posted by another user a few months back but they were out of stock then. Well it's back ! Check it out but don't blame me. I just payed for one but have no clue how good they are.

http://www.gabotronics.com/development-boards/xmega-xprotolab.htm

Problem with Ultrasound Sensor

Hello LMR.

I am working on a current project but seem to be having a ridiculous amount of difficulty implementing an SRF02 Ultrasound sensor. I am using it in serial mode and communicating with an Arduino Duemilanove. The problem is not in the wiring as I triple checked that.

The adruino is supposed to send 2 bytes to the SRF02 [ address, command ] and then receive 2 bytes in response giving the distance measured by the sensor.

Charge Capacitor with Solar Panel

Is anyone aware of a simple circuit that will charge a capacitor with a solar panel (Small one from calculator) and then discharge to an LED via a transistor when the capacitor get's fully charged? The point is to make the LED flash. The frequency of the flashes would depend on ambient light conditions (less light, longer charge time). The closest thing I found is the circuit bellow. Would replacing the +12V with a solar panel still make it work (just take longer to charge)? Also what is the N.C. symbol at the transistors base ?(No Circuit or Normally Closed???)

Canadian Stores

Hello guys. I live in Canada and wanted to ask if any of you know good suppliers of robot parts in Canada. This includes electronics, hardware, discrete components, motors, sensors, breakout boards ect. Basically anything that would be useful in building robots. I like to support local companies and want to save on shipping costs/waiting times. The majority of things I order ship from the US, China or Hong Kong. Please don't give me big companies like Digikey, RobotShop ect. that have offices everywhere.