Matt Merhar
4963fbe50a
UART is broken out to the unpopulated switch header at the front of the board. This isn't quite the same as the V2.0 definition as the system led is always on, not routed through the CPU. Additionally, document that the newer revision of the same "YS25-0402" is supported via the existing PCB-K0402WS-V3.0 target.
2.9 KiB
PCB-K0402WS-V3.0
Following is documentation for a variety of unmanaged switch internally marked as PCB-K0402WS-V3.0. They are sold under many brands.
Original software is running UART on 9600 baud rate.
Note during opening the device: there might be a hidden 5th screw on the back of the device just above the big label, might be covered by a QC sticker.
Brands
- Hisource Hi-K0402WS
- Ztyuav Z-QWYT0402
- SICSOLINK SL-G0402F
- YuanLey YS25-0402 Note: there are multiple revisions of the YS25-0402. This is the newer revision that has a "Vlan" switch on the front.
Programming
Using SPI clamp in-board is the only method for initial installation.
The board has two flash chips BY25Q16BS with 16M-bit size. The front switch, switches between the two flash chips.
These can be programed independently by using said switch - so it is e.g. possible to run the original and new firmware in parallel.
The switch actually controls the HOLD line of each flash chip, and toggling the switch results in a reboot.
If the programming clip keeps HOLD not connected, the flashing will commence on whatever the switch selected, regardless on which chip was clipped.
For the initial flash (at least with flashrom), the bin file produced by the build is much smaller than the flash chip, it is suggested to pad the file to keep flashrom happy: truncate -s 2097152 rtlplayground-*-PCB_K0402WS_V3.bin. Note: do not then proceed to use this resulting padded file for the web flashing (as it bricks the device), use the original unpadded .bin.
What works (expected from label + similar devices)
- All four 2.5GBASE-T RJ45 ports at 10/100/1000/2500 Mbps
- Both SFP ports supporting 1G, 2.5G and 10G modules
- LEDs
PCB overview
Board markings
- Top silkscreen: PCB-K0402W-V3.0 / DIP-K0402WS-V3.0
Top side
Bottom
T2, serial console
J2 pin |
Signal |
|---|---|
| 1 | 3V3 |
| 2 | RX (Input) |
| 3 | TX (Output) |
| 4 | GND |
Power supply
Input power is delivered via barell plug, 12V 1A adapter was provided.
Board has two supply rails. 0.95 and 3.3 volt.
0.95 Core Voltage
Voltage is made by a Techcode TD1720 .
3.3 Voltage
Voltage is created by chip marked as Techcode TD1720.
There seems to have been a miscalculation when choosing the inductor and the device is ~25% more efficient with an 5V power supply.