What is it?

A shield for easily controlling RGB LED Matrix using TinyPICO ESP32 development board. This board takes advantages of the cables that come included with most displays.

This board is designed to work with the awesome PX Matrix arduino library by 2dom

Please note that the current version of the PCB is Blue and not green

What is a TinyPICO?

A TinyPICO is an ESP32 development board developed by the Unexpected Maker. It successfully went through a Crowd Supply campaign!

Why did you make it?

I have been following Unexpected Maker's journey on developing the TinyPICO for quite some time now and I was very excited to be able to add to the amazing eco-system of shields and add-ons Seon has been developing for the TinyPICO.

The RGB LED matrix panels are one of the coolest displays you can use with an Arduino, but there is quite a bit of wiring to connect them up and also they are a little awkward to power. The panels are only about $20 from aliexpress/eBay

This board makes wiring them really simple! The board just slots directly onto the input header pin, uses the ribbon cable that comes provided with most of these panels to connect the pins of the output header and has screw terminals to connect the power cable that comes with most panels.

What makes it special?

I'm pretty certain this was first third-party shield ever created for the TinyPICO! (Bitluni listed his before me though, but mine was designed and built first, I have proof!) I had the board designed and ordered before I even had my TinyPICO.

This really makes using the display as simple as possible. Making use of the cables that comes with the display allows the board to be smaller and less expensive.

Examples sketches for using these displays.

Here are some Github Repos with examples of things that can be done using the board. Most are currently for an ESP8266 but could be easily ported! - Some images and a peanut butter jelly time dancing banana

• A sketch and a webpage for drawing on the matrix in real-time (WIP, need to move webpage onto to the ESP)

• YouTube Subscriber count display

• Tetris text animation, a library for displaying text and numbers being made up of tetris shapes (WIP library)

What is included?

Each TinyPICO Matrix Shield is a kit and comes with the following:

• TinyPICO Matrix Shield PCB
• 220uF 25V Capacitor
• Large resistor (220K) for discharging the Cap
• Schottky Diode (1N5817)
• 3 male pin headers
• 1 Jumper block (colour will vary, probably black)
• 16 pin female header (2x8)
• 16 pin right angle male header (2x8)
• Large Green screw terminals
• Reset Button (New for V1.2)
• OPTIONAL: 2 x standard screw terminals

Stand-off Female Pin Headers Option

One of the options when purchasing is female pin headers that can be used as socket for the Tiny PICO. There are two options a paid of 1x10 headers or a pair of 2x10 headers. Check out the image above to see the difference between them. NOTE: if you select the 1x10 headers, make sure to solder them to the inside set holes, the Tiny PICO is very small!

What is NOT included?

The following components are not provided, but are required to use this board.

• TinyPICO ESP32 Development board (Get yours here!)
• RGB LED Matrix Panel that is compatible with the PXMatrix library wiring (Described Here)
• Most (all?) panels come with a ribbon cable and a power cable, this board requires these.
• A 5V PSU cable of running the display (roughly 5A for a 64x32 model). The barrel jack is standard 2.1mm Jack, but you can also use the optional screw terminals to power the board.
• LDR and 10K resistor if you want to try automatic brightness adjustment. Sample sketch here

Information on assembly and setup

I created a post on my website that has some basic instructions for assembly and setup: Here

Some people have reported issues with leaving it powered on via the barrel jack while programming so it is advised to disconnect power when using the USB, or alternatively take advantage of the $3 Power BLoughR add-on!

Important Size limitations

While this board is was physical dimensions are designed to work with a P3 64x32 display, it should be compatible with most displays. There are a couple of areas where you could get caught up and ways to work around them.

• The Ribbon cable being too short - on some larger displays the provided ribbon cable can be too short to go from the D1 Mini Matrix PCB to the P-Out connector. The ribbon cable needs to be longer than roughly 4cm shorter than the distance between the two connectors of the Display. E.g. on my P3 display, the distance between the two connectors is 13.5cm so my cable needs to be 9.5cm or longer or it will not work
• The PCB does not clear the power connectors - On some smaller displays it is possible that the PCB will be too wide and will hit the power connectors. There needs to be roughly a 5cm gap between the P-in connector and the power connector. Probably the easiest way around this is is to add male jumper headers to the P-in connector and use another ribbon cable to connect this to the input of the display as shown in the image below:

Stand-Off Screws

Some of these displays come with magnetic screws for mounting them on a metal surface. The assembled PCB is taller than the screws but I have added the option of stand-offs that will extend the screws long enough to work. I have unfortunately not found a good supplier of the magnetic screws themselves yet.

There are two sizes available, M3 and M2.5. All my displays are M3 but in Bitluni's video he mentioned he used M2.5 screws so you will need to check which are the appropriate size for you.

Other Notes

• I have tested this board on a 64x32 1/16th display, but it should work with other displays that are wired as per the documentation of the PXMatrix Arduino Library
• Some displays do not use all the pins that are connected to the TinyPICO, you can test if your display uses these pins by checking if they have continuity with ground. If they do, use the red dip switch to turn disconnect these pins from the TinyPICO.

Change Logs

V1.2 (Current Version)

• Added Reset button
• Added space for an LDR
• Rounded the corners of the PCB and added mounting holes

V1.1

• Made PCB Blue
• Updated Silk screen to aid with assembly