This project uses the CH334F USB Hub breakout to connect two mice to the Metro RP2350. In order to prepare the hub breakout for this project there are 3 rows of 4 header pins that need to be soldered to the breakout.

Each row of header pins will get soldered to the 4 pin holes along the sides of the breakout. The two sides next to the USB C plug are the two ports on the hub. The side opposite the USB C plug is the connection back to the Metro acting as USB Host.

Soldering the pins with the long sides going upwards makes connecting to them easier because you can see the labels on the silkscreen, though having them go downwards instead could work as well.

Next connect the two USB Port Breakout cables and 4 female header wires to each of the 3 rows of pins. Be sure to match the following wiring for the USB Host connectors:

• GND to Black or Blue
• D+ to Green
• D- to White
• 5V to Red

I used a Blue header wire for GND instead of Black.

Connect the other end of the header wires to the USB Host pins soldered to the Metro RP2350 on the previous page. 

• GND to Black or Blue
• D+ to Green
• D- to White
• 5V to Red

Note that the data pins are swapped on the Metro compared to the CH334F breakout. On the Metro D- is next to 5V, whereas on the CH334F D- is next to GND.

Be sure to connect D- on the breakout to D- on the Metro, and D+ on the breakout to D+ on the Metro.