Please Help! The LED wall is not working

Hi all,

I’m sorry to report that I’ve caught something horrible and haven’t left my bed in 2 days.

The LED wall is not working and needs to be made ready for Maker Faire.

As far as I can tell, the power is wired up correct. However, the data lines are not connected.

Looking at the led wall from behind, there are three in total, and they are the green wires on the upper right corner of the squares on the right side of the wall.

Each data line needs a 100 ohm resistor connected to it it, and then each one needs to go into the appropriate place in the screw terminal that connects to the network cable.

After that, you need to get the Teensyduino that is connected to the OctoWS8211 programmed.

That is done with a standard Arduino environment that has the OctoWS8211 library installed, and the Teensduino loader application installed on it.

https://www.pjrc.com/teensy/td_libs_OctoWS2811.html
https://www.pjrc.com/teensy/loader.html

The Teensyduino has no lights, so I recommend trying a simple serial example program to ensure the development environment is working.

How the LED strands are arranged

The OctoWS8211 assumes there are up to 8 LED strands connected. A big gotcha I found was that the first strand is missing. So any code you right to address individual LEDs had to offset by 1 strand.

Important notes:

Don’t try to power the Teensyduino from anything else but the RPi on the board if the LEDs are powered. If you try that the LEDs go haywire because of a floating ground.

I have attached my sketch which was scrolling text. This has a bug where the text is limited to 40 characters. It is also designed for a single row of 8 pixel squares, not a 4 x 3 matrix.

Again, sincere apologies. Please contact me here if you have questions.

Its working
https://instagram.com/p/3dD1MzA5SU/?taken-by=funvill

Sorry to hear that you’re sick! Thanks for all the effort in preparing this information dump and letting us know where the LED wall was at. Fortunately, Dan and others managed to figure it out last night and it is looking very colourful! I didn’t look closely enough to see if they had put 100ohm resistors on each dataline, so hopefully someone can confirm that.

Teensy 3 does have an onboard LED on pin 13, so perhaps the blink sketch you were using assumed a different pin (pins 6 and 11 are other possibilities for different boards).

I hope you get well soon and will be well enough to make it to Maker Faire! Take rest.