January 10, 2025

My panel

I purchased my 64x64 2.5mm pitch panel from Adafruit in mid December of 2024.
Let's take a look at the hardware.

Adafruit didn't make these, they purchased a pallet full of them and is now reselling them to their customers.

The panel is labeled "P2.5-2020-32S-64x64-S2".

It is sort of two independent 32x64 panels. One is the top section, 64 wide and 32 tall, and the other is the bottom section, 64 wide and 32 tall. Knowing this, you can invoke symmetry, study just half of the panel and pretty much know what is going on with the other half.

Each section has 12 ICN2037BP chips and 4 RUC7258 chips.
There are 3 chips "shared" in the center section -- two MW245 chips and one 74HC04.
No microcontroller or anything of the sort!

The ICN2037 is a 16 channel LED current sink driver that accepts serial data. Four of these would handle 64 LEDs. We have 12 of these, so there must be four for each of R, G, and B.

The RUC7258 is an 8 channel LED "large screen blanking control" chip. We have four of these, so 4*8 is 32 -- so one channel per row.

3.3 or 5 volts

The panel gets only 5 volt power. Adafruit recommends using a level shifter to drive this panel from 3.3 volts. Is this really needed or is this advice specific to applications that try to drive this from 3.3 volts? Take note that there are a pair of MV245 chips on the board. These almost certainly receive and buffer the control signals. This is the well knowm 74LS245 8 bit transceiver in some form, this particular one made by the vendor "Shenzen Sunmoon". The datasheet is in Chinese. No telling how this chip will feel about being driven by 3.3 volt logic. I may just have to perform the experiment.
Have any comments? Questions? Drop me a line!

Tom's Electronics pages / tom@mmto.org