MAP2 - Learn to Solder kit + Interactive Art Wall


tl:dr - I’m building a “Learn to Solder” kit. Since workshops will be regular, we’ll end up with a lot of assembled dodads on hand. These will be attached to a wall for an Interactive Art installation.

Inspiration for this came via Karmanya Agarwal from the Delhi Asylum who pointed me to this video

It’s a simple circuit consisting of an LDR (photo-resistor) a LED, one Transistor and a few resistors / capacitors - a total of 10 parts. Each module / circuit will be 1 inch square.
The board can be powered in 2 ways - via external 5V power supply, or via on board 3V coin cell. If someone wants to use it as a Badge, the coin cell is handy. But a single pixel isn’t all that interesting.
So, we can keep assembling these squares to form a large installation. The 1 inch square boards need to be attached to the wall, and powered via the 5V external power supply.
Each board draws less than 10mA when the LED is lit. A 5V/20Amp computer ATX power supply will be good to power almost 2000 pixels, resulting in a 44"x44" piece (about 4 feet x 4 feet).
I have the board layout almost done. It’s on the Maker’s Asylum Github repo. The project is called MAP2 {Maker’s Asylum Project #2}

I’m looking at brain storming ideas on how to attach these 1 inch boards to a wall of some sort.

Couple of ideas I already have :

  1. Metal buttons that tailors use. Sew one part to a piece of cloth using conductive thread. Sew the mating pieces to the MAP2 boards. Two or Four buttons per board. All boards are connected in parallel using conductive thread sewn in the cloth.
  2. Use 4 ft x 4 ft MDF or plywood. Stick strips of conductive copper tape. Solder the boards to the copper strips using right angle header pins.

Here’s the schematic :
map2.pdf (58.7 KB)


Why not use simple header strips to connect the boards together and use the mounting holes to attach to the MDF panel you’re already thinking about? something like what the EMS people do on their table kits


Removing one module from somewhere within the matrix is mighty difficult once it gets large. One of the problems we (WyoLum) faced with our TiM LED matrix modules which used interconnecting headers like the one your pictured above. We’re now going to use magnetic mounting. But that’ll be too expensive for this application.


Here’s what it looks like finally :
from the top :

from the bottom :

Here’s the current schematic : map2.pdf (58.3 KB)
and the Bill of Materials : map2_BoM.pdf (33.5 KB)

I added a row of castellated pads on the 2 sides. Maybe different kinds of attachment possibilities can be worked out.


We’ll create another version of the board with surface mount parts, or modify this same board to accept either through hole or SMD parts.


what if we were to bend the connector pins at like a 45 degree angle so that the individual pixels are easier to put in and take out? I’m only worried about how durable a solution it would be.


here’s a handy “Learn to Solder” guide (thanks to Shreekant Pawar)


Finally finished the TH+SMD version. I think this is the one which will go for prototypes.
Capacitors are 1210
Resistors are 0805
Transistor is SOT-23-3
LED is TH but an SMD package can be soldered to the same footprint.
LDR is TH.


Anool are you getting these fabbed as a panel?


Nope. De-paneled. I ordered out 20 from PCBpower and will send a bunch to the Delhi Asylum.


Here’s what a panel/matrix of MAP2’s will look like.


Boards have arrived. I got 20 nos. fabbed via PCBpower in Ahmedabad for INR1500.

Hopefully, we’ll receive the parts at the Asylum today. We’ll assemble a few, and then leave the rest for a “Learn to Solder” workshop during Genuino Day on April 2nd.


First MAP2 board assembled and works as planned.


Here’s a quick video.
MAP2 assembled


whoa! It’s been more that a year and a half that these boards have been just lying around at the Asylum. Anyhow, I finally managed to buy new parts (the original batch of parts disappeared), and with a lot of help from Samata, all 20 prototype boards are assembled and mounted on a base board.

20 tiles are interesting, but 200 would be awesome.


Here’s a short video showing how it reacts to light and darkness.

MAP2 Video