Backup data and how to use it with our controllers
Nowadays, we are mostly working with digital pixel LED strip with IC type WS2815. Apart from it being a 12V strip (handy online tool to calculate total parts needed for projects with this strip type here) it also has one special feature – Backup data.
It is essentially a second data line. It can help you in case single pixel in the strip is damaged. Instead of all pixels turning black, the data is still send, and received undamaged, in the following pixels and you need to worry only about the single diode. But how you can connect this type of strip with our devices?
Use Ground for Backup #
After we started to work with this type of strip, we did a lot of testing. There are two options how to connect Backup pins, hence Backup signal, to the controller.
One is directly connecting to the Ground pin on the controller. Here, the distance can not be long. In our experience, we are talking about 20cm max.
The second option is to connect the Backup to the ground on the strip.
“B” on the controller does not stand for Backup #
A lot of customers are using one particular connection to, incorretly, connect data to the controller. On the controller, you have 4 pins on each output, and one of those ports is marked as D/B. This pin is used for Differential data transfer. Whenever you are using long distance runs and employing The Symmetrizer gadget, this is the pin that you use for the negative data transmission.
