Skateboard with PIC microcontroller and LEDs

Step 4 Build the circuit

This circuit is based on a PIC16F870 microcontroller. This controller was chosen because of the number of input/output pins, and the fact that I have a programmer for this chip. The input is a single pushbutton that cycles through each of the 15 LED flashing patterns. The outputs drive transistor switches, which turn on the individual LEDs. The transistor switches were used to keep the power dissipation through the microcontroller under the specified maximum (200 mA max). The power supply for the circuit is a slightly modified LM317 kit that is available at Ramsey Kits. The power supply was chosen because the circuit will be potted (encased in potting epoxy) and the LM317 will not require a heatsink. The kit provided a ready made circuit board and parts to construct the power supply, DC input is provided by six AAA batteries (9 volts). Since the kit is designed to accept AC power input, I removed the Diode bridge rectifier and large cap as my input is already DC. The power output was adjusted to achieve 5 volts for the microcontroller and the full 9 volts are used to power the LEDs. The entire circuit was tested on a bread board, then built on a prototype board from radio shack. The parts list can be derived from the schematic. The assembly code and video of testing are also attached.

Edited: Here is the YouTube video:

Comments

[jimmytvf]

seems like a christmas tree, but is very cool though