dc8wan/debubo
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

README: minor improvements

Browse Source
This commit is contained in:
Sebastian Krzyszkowiak
2024-08-11 09:17:03 +02:00
parent 5a2f58e23f
commit 3dc38f27ed
1 changed files with 6 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
README.md
View File

@@ -7,9 +7,8 @@ A 4-layer PCB with STM32G071CB microcontroller equipped with two USB Power Deliv
STM32 can communicate via [Power Delivery protocol](https://www.usb.org/document-library/usb-power-delivery) over both USB-C plug and "DATA/PWR" USB-C receptacle, STM32 can communicate via [Power Delivery protocol](https://www.usb.org/document-library/usb-power-delivery) over both USB-C plug and "DATA/PWR" USB-C receptacle,
which are directly connected to each other to pass power and USB 2.0 data through. which are directly connected to each other to pass power and USB 2.0 data through.
CH342 provides access to 3.3V UART on USB-C plug's SBU pins and to STM32 over "DBG/MCU" USB-C receptacle, allowing it to be flashed without additional tools. CH342 provides access to 3.3V UART on USB-C plug's SBU pins and to STM32 over "DBG/MCU" USB-C receptacle. This allows to access debug console on devices that only
expose it on SBU pins after entering an alt-mode or sending custom VDMs over PD, and to flash STM32 without additional tools.
This allows to access debug console on devices that only expose it on SBU pins after entering an alt-mode or sending custom VDMs over PD.
Debubo can also be used as a Power Delivery sniffer / injector (as a man-in-the-middle). Debubo can also be used as a Power Delivery sniffer / injector (as a man-in-the-middle).
@@ -30,7 +29,9 @@ It also gives you control over Rd / Rp resistors on both CC pins, allowing it to
## Input / Output ## Input / Output
Debubo breaks a bunch of extra interfaces out as pin headers: USB-C plug's SBU lines, 5V and 3.3V power, SWD, I2C, UART to MCU, SPI, GPIO for custom use and MCU reset line. Debubo breaks a bunch of extra interfaces out as pin headers: USB-C plug's SBU lines, 5V and 3.3V power, SWD, I2C, UART to MCU, SPI, GPIO for custom use and MCU reset line.
There's also a LED and a push button for custom purposes. Pins of unused interfaces can be repurposed as GPIO. There's also a LED and a push button for custom purposes. Pins of unused interfaces can be repurposed as GPIO or DAC/ADC where available.
Note that current drawn from 3.3V rail (including power drawn by STM32) should not exceed 10 mA - it's provided by CH342's integrated LDO.
USB-C plug's SBU lines are connected to CH342's UART0 (TX - SBU1, RX - SBU2), STM32's USART1 (TX - SBU1, RX - SBU2) and USART4 (TX - SBU2, RX - SBU1). USB-C plug's SBU lines are connected to CH342's UART0 (TX - SBU1, RX - SBU2), STM32's USART1 (TX - SBU1, RX - SBU2) and USART4 (TX - SBU2, RX - SBU1).
@@ -39,7 +40,7 @@ STM32's bootloader-capable USART2 is connected to CH342's UART1.
## Modifications ## Modifications
- two solder jumpers near the plug (JP1, JP2) allow you to bridge top and bottom D+/D- pairs on the USB-C plug together - two solder jumpers near the plug (JP1, JP2) allow you to bridge top and bottom D+/D- pairs on the USB-C plug together
- cutting the trace on the bottom solder jumper (JP3) allows you to provide your own Vio (note that STM32 USART will still be 3.3V) - cutting the trace on the bottom solder jumper (JP3) allows you to provide your own Vio to CH342 (note that STM32 USART will still be 3.3V)
## Firmware ## Firmware