Matek USB Power Meter

       I got this for quick checking of USB devices and stopping chargers that do not properly terminate its charge cycle. It is not very accurate but for estimating a ballpark figure, it is fine.

       I was using this but I noticed it got damaged probably from the cable accidentally being pulled so I had to repair it.

The USB power meter

Its transparent heatshrink wrap removed.

Four screws are undone to remove the front PCB bezel.

Now, to unsolder the LCD display.

With the LCD removed, we see some basic components. Its main uC is a PIC16F1936 with some basic support components.

This is my problem. The USB jack is surface mount without much support so it is easily detached from the PCB.

Two pads came off.

The pad has a trace to connect the shield can to the circuit GND through a ceramic capacitor.

By resoldering the pins and using a generous amount of superglue on the damaged pads and under the connector, I was able to securely fix it again.

Here is a comparison between a Portapow USB power monitor and the Matek power meter.

It is displaying voltage.

Matek: 5.20V
Portapow: 5.16V

Now, it is showing current.

Matek: 0.19A
Portapow: 0.16A

And finally, power.

Matek: 1.0W
Portapow: 0.85W

       There is a little bit of difference between the Matek and the Portapow. I have tested the Portapow to be pretty close to my other meters so the Matek is off by a small amount. It is not to bad though and still useful for ballpark readings.

Page created and copyright R.Quan ©25 Dec 2015.