RK3588 Handheld Host

Project Description: This project
uses the RK3588 core board and a custom-made mini-PC chassis. It includes one HDMI port, two USB 3.0 ports, one USB 2.0 port, one 2.5G Ethernet port, and one DC power connector. The circuit board is compressed to 80mm × 100mm, and the overall device is compressed to within 100mm × 120mm × 50mm.
Open Source License:
This project is open source; please indicate the source when reprinting.
Project Functionality: This
project implements a palm-sized Ubuntu 22.04 host with approximately 6 TOPS of performance. It can connect to an external keyboard and mouse, and connect to the network for light office work.
Project Attributes:
This is the first public release of this project, and it is my original work. This project has not won any awards in other competitions.
Project Schedule:
February 12, 2024: First version of the circuit board applied for and manufactured;
February 21, 2024: Consumables application approved, total cost of PCB+SMT: 1268.72;
March 2, 2024: Circuit board arrived;
March 4, 2024: Hardware circuit debugging completed, debugging record attached;
April 25, 2024: Casing fabrication and installation completed, physical product and power-on test video attached;
Design Principles:
1. Power input uses two MOSFETs to build a reverse polarity redundancy filter circuit;
2. Uses synchronous rectification chips to build 12V to 5V and 3.3V circuits, and uses an LDO chip to implement the 1.8V circuit;
3. Uses Fusb302mpx to implement the Type-C interface handshake protocol, and uses a 24-pin Type-C socket to implement a full-function Type-C interface;
4. HDMI interface uses IIC communication control, and all HDMI socket pin signals are protected by ESD chips;
5. RTC battery uses CR1/N3 cylindrical battery, which saves circuit board space compared to 2032 battery;
6. Reserved power signal, reset switch, BOOT switch, and RECOVERY switch;
7. Use an HR911130A RJ45 socket with a transformer to save space compared to an Ethernet transformer;
8. Use a double-layer USB 3.0 socket to trade vertical space for board area;
9. Use a TF card for the hard drive, which is small in size and supports SDR104, with a speed sufficient for light office use;
Software Note:
The firmware device tree needs to be trimmed, otherwise the RK3588 will get stuck at the PCIE clock detection part during boot. You need to download the official RK3588 Ubuntu 22.04 source code, open the device tree file and modify it.
1. In the kernel-rockchip/arch/arm64/boot/dts/rockchip folder: Modify rk3588-nanopi6-common.dtsi and set the PCIe related nodes to disable; 2. In the kernel-rockchip/arch/arm64/boot/dts/rockchip folder: Modify rk3588-nanopi6-rev09.dts and set the PCIe, hdmi1, and hdmirx related nodes to disable; The
device tree adaptation code file is attached. It can be further modified according to your hardware. In actual testing, after modification, Ubuntu 22.04 boots within 10 seconds;
Physical demonstration
 
design considerations
## Hardware 1. Power input section Q2 1. The MOSFET was incorrectly connected, causing a short circuit and burning out after power-on. Q2 was removed. 2. VDC power-on mode control is cumbersome; R19 was removed to configure direct power-on mode. 3. The casing design, prioritizing aesthetics, did not include mounting notches for the power switch and RJ45 socket. These need to be removed during installation, and then soldered back on after the casing is reassembled.
Other
physical examples are shown in the attached "Final Result" document;
a circuit board debugging video can be found at https://www.bilibili.com/video/BV1Ai421f7eu/?share_source=copy_web&vd_source=45e1cd8ec6771b34f1270c7263739bb0;
and a final product demonstration video can be found at https://www.bilibili.com/video/BV1u1421X7DS/?share_source=copy_web&vd_source=45e1cd8ec6771b34f1270c7263739bb0.