Raspberry Pi’s Compute Module 4 (opens in new tab) looks like a credit card with chips soldered to it, but is lacking in ports, which have to be provided by a carrier board tailored to the job you want the pairing to carry out. This usually involves a couple of HDMI ports, some USB connections, or even a PCIe slot, but a new carrier from Bigtreetech, brought to our attention by Liliputing (opens in new tab), goes a step further by having a built-in five-inch touchscreen.
Known as the Raspberry Pad 5 (opens in new tab), the result is a sort of Linux-powered iPad very-mini, or the smallest Android tablet you ever saw that doesn’t have its own battery. The IPS touchscreen has a resolution of 800x480 pixels and uses the Compute Module’s CSI video connector. Around its edges, you’ll find an HDMI connector, a USB-C for power and flashing the onboard e-MMC storage, three USB Type-A ports, an Ethernet socket, a micro-SD card reader, and the Raspberry Pi’s signature 40-pin GPIO interface (opens in new tab). The whole board measures just 121 x 76mm (4.8 x 3in).
A Compute Module isn’t included in the package, which may be a problem given recent stock shortages, and nor is any sort of base for the board. A screw riser is helpfully placed at each corner, meaning the board can be directly placed on the outside of something to control it or have a base 3D printed for it if you intend it to be portable. Extra features include a switch that toggles between flash mode and the CAN bus, and an onboard RTC powered by a coin cell.
One use-case posited by Bigtreetech is as an external control box for a 3D printer motherboard, with a Raspberry Pi Pico (opens in new tab) acting as an intermediary. It can act as a smart mirror, digital photo frame, door controller, or even as a small portable computer if you can solve the power supply issue.
Raspberry Pad 5s are available now from the Biqu store for $99, a discount from the usual price of $129, without a CM4. Add a Pi, and prices naturally rise, though only CM4 models with 2GB of RAM (including the new Lite (opens in new tab) model) appear to be available.