December 2, 2008

Ping pong photos (troubleshooting stages)

Filed under: Intro to Phys Comp — Tags: , — *aly* @ 11:41 pm

Arty Ping Pong


November 20, 2008

the saga of the 5940tn daisy chain

Filed under: Intro to Phys Comp — Tags: , — *aly* @ 10:50 pm

Our first foray into daisy chaining the Texas Instruments TLC5940tn led driver and using the arduino library ( was unsuccessful. The LEDs from the first chip worked correctly, but the second half of the LEDs on the second chip stayed solidly on and the first four LEDs lit up in a pattern paralleling the first chip. After much troubleshooting (we tested the chip, the LEDs, the wires, the code) we met with Tom who gave us a quick tutorial on Arduino libraries. As it turns out, our wiring and hardware was all fine. This library uses a variable for the number of TLC chips that is defined in the config file and must be changed there (the same erratic behavior described above still happens if the particular variable is redefined in the regular code). AND when the configĀ  file is edited, the file in the library with the .o extension must be deleted for the change to be effective which is the step we were missing.

And so, without further explanation, our three chips daisychained: