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Hey everyone, what’s up?

So here’s something super interesting and cool: SANDWICH DOT IO.

It’s a Raspberry Pi system with onboard power, a dedicated cooling layer, and even RGB LEDs for aesthetics.

This setup was created to address a problem I encountered while working on a Raspberry Pi-based project:

I wanted to create a small game emulator using the RPI 3B+, but the problem was the power supply. A 5V adaptor was used for powering the Raspberry Pi.

A fan was also required to keep the Pi cool, but I had to add another 5V supply for it as we cannot plug it directly into the 5V of the Raspberry Pi.

So I made this simple system that consists of three layers, each made from FR4 PCB. The first layer, or battery layer, contains a power management IC (IP5306) with four Li-ion cells that give a stable 5V output for running the Pi and other stuff.

The second layer holds the Raspberry Pi in place by using the four mounting holes present on the Pi. I used PCB standoffs to hold the Pi in place.

It also has RGB LEDs (WS2812B) to make this setup look cool and hip; they are powered by the onboard Attiny85 MCU, and the color is controlled by a vertical push-button.

The third layer contains a cooling fan setup; a DC 5V fan is placed right on top of the Raspberry Pi processor and is powered by a proper fan driver made by using a Mosfet IC controlled by an Attiny13A; this concept was reused from one of my previous projects.

Because this setup has active cooling, the Raspberry Pi processor works great, and we could use this setup for power-hungry applications like running an emulation OS and playing DOOM, for example.

This Instructables is about the whole building process of this setup in-depth, so let’s get started.

Following were the materials used in this built-

Custom PCBs
Raspberry Pi Model 3B+ (can use any Pi version)
DC 5V Fan
PCB Standoffs
Attiny85 THT
Attiny13A SMD
AO4406 Mosfet IC
WS2812B LEDs
JST connectors
JST wire harness
Li-ion cell 18650 holder
Li-ion cells
IP5306 IC
1uF Capacitors
Type C USB Port
Normal USB port
Vertical Switch
Slide switch ON OFF
indicator LEDs 0603 package
SD Card”

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