Project Description

Use RK3588 core board, self-made mini host baseboard, leave 1 HDMI interface, 2 USB3.0 interfaces, 1 USB2.0 interface, 1 2.5G Ethernet interface, 1 DC power interface, compress the circuit board to 80mm×100mm, and the overall equipment to 100mm×120mm×50mm.

Open-source protocol

This project is open source, please indicate the source for reprinting.

Project-related features

Realize palm-sized Ubuntu22.04 host, with a performance of about 6TOPS, which can be connected to an external keyboard and mouse, and connected to the network to achieve light office.

Project properties

This project is the first public and is my original project. The project has not won an award in another competition.

Project progress

On February 12, 2024, the first version of the circuit board will be applied for plate making;

On February 21, 2024, the application for consumables was approved, and the total cost of PCB+SMT was 1268.72;

The circuit board will arrive on March 2, 2024;

On March 4, 2024, the hardware circuit debugging was completed, and the debugging record is shown in the attachment;

On April 25, 2024, the processing and installation of the shell will be completed, and the physical object and start-up test video are shown in the attachment;

Design Principles

1. The power input uses two MOS tubes to build an anti-reverse redundant filter circuit;

2. Use synchronous rectifier chips to build 12V to 5V and 3.3V circuits, and use LDO chips to realize 1.8V circuits;

3. Use Fusb302mpx to implement the TypeC interface handshake protocol, and use a 24PTypeC socket to achieve full-featured TypeC;

4. The HDMI interface is controlled by IIC communication, and all HDMI socket pin signals are protected by ESD chips;

5. The RTC battery uses CR1/N3 cylindrical battery, which saves the space of the circuit board compared with the 2032 battery;

6. Reserve power signal, reset switch, BOOT switch, RECOVERY switch;

7. Use an RJ45 socket with a transformer HR911130A to save the space of the Ethernet transformer;

8. Use a double-layer USB3.0 socket to exchange the longitudinal space for the circuit board area;

9. The hard disk uses TF card, which is small in size and supports SDR104, and the rate meets the needs of light office use;

Software Description

The firmware device tree needs to be cropped, otherwise RK3588 will be stuck in the PCIE clock detection part of boot auto-start, you need to download the official Ubuntu22.04 source code of RK3588, open the device tree file to modify:

1. In the kernel-rockchip/arch/arm64/boot/dts/rockchip folder:
Modify rk3588-nanopi6-common.dtsi to set PCIe-related nodes to disable;
2. In the kernel-rockchip/arch/arm64/boot/dts/rockchip folder:
Modify RK3588-nanopi6-rev09.dts to set PCIe, HDMI1, and HDMIRX related nodes to Disable;

The device tree adaptation code file is attached and can continue to be cut according to your own hardware, and Ubuntu22.04 can be booted within 10 seconds after the measured cut;

Physical display

Design considerations

## Hardware
1. The Q2 mos tube in the power input part is connected incorrectly, and it is short-circuited and burned after power-on, and Q2 is directly removed;
2. VDC power-on mode control, controllable power-on is more troublesome, remove R19 and configure it as direct power-on mode;
3. Considering the aesthetics of the shell design, the installation gap of the power switch and RJ45 socket is not reserved, which needs to be removed during installation, and the shell is installed and then repaired.

Other

The physical display is shown in the annex "Final Results";

Circuit board debugging video: https://www.bilibili.com/video/BV1Ai421f7eu/?share_source=copy_web&vd_source=45e1cd8ec6771b34f1270c7263739bb0

Final product demo video: https://www.bilibili.com/video/BV1u1421X7DS/?share_source=copy_web&vd_source=45e1cd8ec6771b34f1270c7263739bb0