Do you have DE-9 connector on your laptop? I don't :) You obviously can use that RS232 to USD Adapter cables, but DIY guy can make his own cable, right? Add bluetooth too perhaps?
Let's take a closer look at the supplied RS232C cable:
Here is a schematics I reversed from the pcb:
This thing pulls up RX line when IR diode senses light from the meter. UT61E sends inverted serial signal to its IR led.
There is a bit of space inside this sensor box. And I need to fit a circuit inside, which senses IR light and pulls down RX line from 3.3V to Ground. This is classic UART serial interface.
Unsolder everything from the pcb except IR sensor diode.
R1 needs to be set lower than original because we are using 3.3V now and there is not enough juice to turn Q1 on fast enough with 4.7k.
OK, then I made this piece of art:
At this stage you already can connect UT61E to the microcontroller or Arduino or anything else which understands 3.3V UART. But I started it as USB mod, so we continue.
I have some CP2102 Serial UART TTL USB converters laying around and this is enough for this mod. Just connect that 3 wires and there we go.
Raw output from the meter:
Correct serial port settings for this meter are: speed 19200, bits 7, stop 1, parity odd.
But, there is more! You can even add a Bluetooth feature to this UT61E multimeter. It's easy as soldering 6 wires to some serial bluetooth module with this mod.
UT61E with Bluetooth, sounds great! Interested?