Datasheet

Bi-Color 24 Bargraph

This version of the LED backpack is designed for these bright and colorful bi-color bargraph modules. Each module

has 12 red and 12 green LEDs inside, for a total of 24 LEDs controlled as a 1x12 matrix. We put two modules on each

backpack for a 24-bar long bargraph (48 total LEDs).

This backpack solves the annoyance of using lots of pins or a bunch of chips by having an I2C constant-current matrix

controller sit neatly on the back of the PCB. The controller chip takes care of everything, drawing all 48 LEDs in the

background. All you have to do is write data to it using the 2-pin I2C interface. There are three address select pins so

you can select one of 8 addresses to control up to 8 of these on a single 2-pin I2C bus (as well as whatever other I2C

chips or sensors you like). The driver chip can 'dim' the entire display from 1/16 brightness up to full brightness in 1/16th

steps. It cannot dim individual LEDs, only the entire display at once.

Attaching the bar-graph modules

Remove the parts from packaging and place the LED bargraphs over the outlines on the top of the PCB.

The bargraph must be soldered on the correct orientation or it will not work! Check for the side of the bargraph that

has printing on it. Then look for the outline on the PCB that has "Text on this side" marked!

Do not solder the matrix onto the back of the PCB, it won't work either!

Pay close attention to the instructions for positioning the bargraphs. They must be oriented correctly to work

and is almost impossible to remove them once soldered to the backpack!