Lenovo power distribution board

Sometimes, I find it frustrating not to have a readily available high-power power supply, while my laptop charger can meet most of my needs (20V, 11.5A). However, the downside is that it only has one port, which isn't enough. This board can expand that, making it easier to view power and other information.
Specifically,
the top panel

has a standard Lenovo square connector (available on Taobao).
The output uses three XT30 connectors; the one for the computer is a 2+2 XT30 because a signal cable is needed for the computer to recognize fast charging.
The other two XT30 connectors are standard, as that's all I had on hand (laughs).
The chip is an INA3221 (TI's). It has three voltage and current detection channels, and the maximum voltage across the shunt resistor is no more than 165mV. My computer is 20V 11.5A, so I'll
calculate the maximum as 15A:
u = IR = 15A 5mΩ = 75mV
p = IIR = For 1.125W
, I chose a 3920 resistor; 5mΩ (5W) is more than enough, mainly for aesthetics (lol). You could also use a 2512 resistor (I haven't tried it).
As for the wiring, I wound it myself; it's not technically difficult. As long as you don't connect it backwards, there shouldn't be any problems. I used 1.25 square millimeter standard wire, and in actual testing, there was no temperature rise at 11A

. The program:

I wrote it myself using MicroPython (a patchwork), and it works. Other languages ​​should also work. The implementation isn't difficult, but I won't show the program (to avoid embarrassment) (laughing). It uses an ESP32 microcontroller.