Testing the LCD and Ping modules

Measuring distance with ultrasound
Spent the afternoon trying out the LCD and ping modules, and playing with the darlington array and red, green, blue LEDs. The LCD worked right away, and so did defining custom characters. The interfacing is ridiculously easy! I noted there is a Basic Stamp chip on the LCD and on the Ping module, which explains a lot.

The ping (ultrasound ranging) module worked right away as well. The accuracy is down to the centimeter, but it does not "see" round things such as the lamp.

I connected the red, green, and blue LEDs to the Darlington array, and connected the array to the Stamp. Focused the LEDs on one spot. The idea: mix the three components to create any hue I want. I tried to dim the LEDs though pulse width modulation, but, alas, the Basic Stamp is too slow for that. As soon as I try to get more that 6 different levels of brightness or so, the pulses become visible.

Apart from that, I possibly fried the red LED a wee bit by soldering it onto the board while the juice was on (it got grounded without a resistor - nice and bright, but too much oomph). The light cone is wider, too. The net result: the colors don't mix well.