• The PCB Assembly Process for this project begins with applying solder paste to each component pad with a solder paste dispensing needle. We're using 63/37 Sn-Pb solder paste.
• Next, we select all of the SMD components and place them in the correct spot.
• We next place the board on our Mini Reflow Hotplate, which heats the PCB from below up to the solder paste melting temperature of roughly 200 °C. Solder paste melts permanently and connects all SMD components to their pads.

• We begin the assembly procedure by attaching four hex M3 PCB standoffs to the four mounting holes of the Pi 4. We're utilizing four 6.7mm-long hex standoffs here.
• Next, we install the Pi Holder Part to the bottom side of the Pi 4 using the M3 Standoffs.

To improve the aesthetics of the design, we created two add-on parts: a line printed in orange PLA and placed on the front side, and a nametag printed in two colours and placed on the top of the front body.

• We applied Super glue to the bottom side of the 3D printed line and then placed it on the front body.
• Super glue is next applied to the rear side of the Pi Box nametag, which is then placed on the top side of the front body.

• We now begin the front section assembly procedure by sliding the 5-inch display inside the front body section. To keep it stationary, we used hot glue to adhere the screen to the body.
• We connected the FPC cable (supplied with the display) to the Pi 4's MIPI DSI connector in the correct order.
• The other end of the FPC cable is then connected to the DSI connector on the 5-inch display.
• The Pi is then placed inside the front body and secured in place with four M2 screws tightened with the Pi holder and screw bosses positioned inside the body.

• The Power Module is now positioned over one of the display's PCB standoffs and secured with an M2.5 bolt.
• We then used a JST Wire Harness connector to attach its positive and negative terminals to the power module's Vout and GND terminals.
• Next, the JST wire harness connector is connected to the Raspberry Pi's 5V and GND via the 40-pin GPIO header connectors.

• We begin the power source assembly process with the front section by first positioning the rocker switch and then connecting the GND terminal of the Power module to the NC of the rocker switch.
• We then connected a RED wire to the VIN of the power module and another to the NO terminal of the rocker switch. This additional wire attached to the NO terminal will be linked to the GND of the battery pack; the switch will serve as a break between the Power module and the battery pack circuit.
• The rocker switch terminals were close to the FPC cable connecting the display and Raspberry Pi; therefore, we used Kapton tape to wrap the rocker switch terminals.
• We connected the VIN and GND wires to the VCC and GND terminals of the Battery Pack circuit.

• The final assembly process begins with placing the battery pack circuit inside the back section.
• The battery pack circuit is subsequently secured in place with two M2 screws that are put into the screw bosses on the back section.
• We then placed the front section on top of the back section, followed by the base holder on the device's bottom side. It is then held in place with four M2 screws. This base holder part connects the front and back sections from the bottom.
• We put two M2 screws to the left and right faces, permanently fastening both components together and completing the assembly procedure.

We are currently using the RecalBox OS, a retro game emulation OS that supports a wide range of previous consoles, including the GameCube, PS1, PS2, and Xbox.

Recalbox OS is simple to use and comes pre-installed with a large number of free games.

Furthermore, it is compact and runs efficiently on low-end Raspberry Pi computers, making it excellent for the Pi 4, which operated directly off an SD card.

The installation process is straightforward:

• We downloaded and installed Raspberry Pi Imager, an imaging utility application similar to Etcher or Rufus. It includes a list of Raspberry Pi-supported operating systems, which you may download and burn directly to the boot USB.

https://www.raspberrypi.com/news/raspberry-pi-imager-imaging-utility/

• Next, we choose the OS we wanted to install, which was the Recalbox OS for the Pi4.
• After that, the raspberry pi imager completes the installation process, and we just install the SD card on the Pi4 and power it on; the first boot will take an additional 2-3 minutes.

Here's the end result of this small build: a working Mini Raspberry Pi PC or console. Because this device falls somewhere between a Mini PC and a Console, it's difficult to define a specific use case for it; for the time being, we're utilizing Recalbox OS to utilize it as a retro gaming emulation station. This setup can also run DOOM, because of the Raspberry Pi 4.

Using the Raspberry Pi 4's Bluetooth, we can link our controller to play games or connect any device, such as a keyboard, using the USB port.

Because of the onboard battery pack, we can take the Pi BOX anywhere. The device's backup is more than one and a half hours, which is adequate given the battery pack utilized, as we simply chose a 3S battery pack. Maybe in a future revision, we will add a larger capacity battery pack to this design, allowing it to last a full day of use.

Special thanks to HQ NextPCB for providing components that I've used in this project; check them out for getting all sorts of PCB or PCBA-related services for less cost.

Thanks for reaching this far, and I will be back with a new project soon.