Hello. This project involves upgrading a big world map I made for my family that had individually non lit colored pins for each major city we've visited. The colors have since faded and it needs a refresh.
We are four people in my family so the old map had four colors for each person, and one color local cities in our country. So, it's five colors, over 200 pins. I want to have each pinhead with small leds. Also, an arduino project would help me solve some technical issues I believe exist. If everything goes well I have some ideas about how to extend it, interactivity, IoT, world domination, etc.
I've made this thread for documenting my progress with information I've gathered and used on functional tests. At the moment this very much a solo project but I'd be happy to read your thought and ideas. It has been years since I've programmed and soldered. Even this duemilanove I have has been sitting in a box for about 15 years. I'm getting back into it, so, let's get to it.
Functional Arduino tests.
In total I need a bit over 200 leds that have to light up on command. Doing over 200 leds with just one old arduino and no planning may add complexity and have excessive power requirements. I've searched the web for information on doing this and I've decided on the following solution:
One Arduino (in my case a Duemilanove) in which 5 PWM pins are used to control 6 MAX7219, with 64 leds possible each. Using this solution also makes it possible to "address" each led individually (which is awesome!). One person in the family will need two MAX7219, the rest one. I believe this is the best way I can debug the project if needed.
Here is a test:
Don't know how to upload videos yet, GIF in the meantime.
This is a test of the sorted out pins for the 1088AS 8x8 led matrix. So I can individually wire them and put them on the map.
Wiring reference:
This is a flicker test for MAX7219 with a big 8x8 led matrix. I despise flickering leds but it will be ok. Of course, the small 0402s will behave slightly different.
Sorting out the mess that are 1088as pins.
The MAX7219 modules that I bought come with a 1088as 8x8 led matrix. I was not expecting the pin organization to be confusing and initially all I got were weird lines that made no sense. After much googling I found this video:
simplyput2796 explained the pins organization extremely well and, thanks to him, I made this and I'd like to share it with you. With this organization the 8x8 led matrix will be right side up. Also, it turns out a lot of this "decoding" can be found in the MD_MAX72xx_lib.h from the "MD_MAX72xx Arduino library" but I was not ready to read it at the time.
MAX7219 with custom "decoded" 1080as. According to simplyput2796 using hex digit with one character is easier and I agree.
MAX7219 with custom "decoded" 1080as with fancy photos for future reference
Light pins. Old and New
Working test if the light pins:
Comparison between the old and the new pins with 0403 leds. The black one is for support and it is all fixed in place with UV resin:
