Erica's New Led System

A project log for Erica The Cyber Rhino

An interactive artwork built to help with the goals of rhino conservation and electronics and computer science outreach

tyler-ward-scorpiaTyler Ward (Scorpia) 03/06/2014 at 19:350 Comments

Erica’s original system was based around the TLC5940 LED driver chip which was controlled directly by one of the raspberry pis in Erica with an ATtiny45 on the pi daughter board to provide the clock signals.

Erica old LED setup

Erica old LED setup

For anyone who saw Erica in person you will have noted that the LEDs were not always working. Although we haven’t been able to work out the exact cause of the issue we believe it may be due to the chips either overheating (ambient temperatures inside Erica got up to 58C when in the Marlands), or due to large voltages being inducted onto the signal wires linking the drivers.

To resolve these issues we have created a new LED controller design for Erica. The following are the major improvements over the previous version:

Below you can see the new controller design being tested. The controller itself is on the white breadboard, the blue breadboard is the transmitter that will put on the mech pi daughter-board. The cat5 cable connecting the two boards for this test is over 30m long so it shouldn’t have any trouble with the distances inside Erica

Erica new LED controler test

Erica new LED controler test

Rather than build these controllers on strip-board we have designed a custom PCB (Printed Circuit Board)

Design For Erica's new LED controler

Design For Erica’s new LED controler