10 Channel Level Shifter with Pi Header

This is a very quick and easy solution to an ever-present problem in my electronics life: Some Microprocessors and Sensors/Devices work on different voltages, and their IO pins are not X volt tolerant... Of all of these, the dear Raspberry Pi, as well as the RP2040 and ESP32/ESP8266 is most guilty. On the sensor side, Ultrasonic sensors, infrared thermometers etc, all want either 5v logic, or 3v logic...

What follows then is usually an ugly resister/divider circuit on a breadboard, unstable connectors, unreliable data etc. This usually ends up costing a lot of time in debugging and getting it to work reliably. If you wanted to use this for something like SPI or I2C, it won't work either ...

You could buy a readymade PCB module from somewhere online., they work, and are quite cheap, but Where is the fun in doing that?

I decided to design my own, but with a bit of a twist added... I want it to be able to plug into the Raspberry Pi GPIO Port. I also wanted a lot of GPIO Channels, which had to be bidirectional. No sense in going only one -way!

I came up with this:

A BSS138 N-Channel Mosfet, with two 10k resistors, per channel.

The circuit is not new, and it is not unique either. But it works beautifully. Do I need to say more?

Assembly is easy, as all components are 0805 or bigger. Components are cheap as well. It finally makes working

with the Raspberry Pi a pleasure, as I do not have to rely on breadboards and other funny stuff, and my expensive

sensors will be safe, at least if I don't connect them wrong :)

How to Use:

Using this board is very easy. On the left-hand side, there are two headers, marked H1 and H2.

These are the power inputs, HV for the high voltage ( for example 5v ) and LV for the low voltage

( 3v in our example ). Not that you have to connect BOTH grounds, as the device requires a common ground.

Now, on the very right-hand side, is header H3. It is labelled as :

LV1 - HV1

down all the way to

LV10 - HV10

You can now easily connect the signals that you need to be converted.

As an example for the Raspberry Pi, you will connect the signal wire(s) from the Pi to the LV Channel,

and your 5v sensor or device to the HV Channel. You only need to make sure that the channel numbers match!

Bi-Directional signals like I2C and SPI also works very well.