Wii camera using bi-direcitonal logic level

Hi Team,

I am going to attempt to attach an old wiimote camera to the arduino pro micro 5v. I have been given a diagram that is known to work. I would like to attach the camera via a bi-directional logic level shifter 5v to 3.3v (SKU: CE07510). My question is, do I still need to solder the (pull up) resistors shown in the attached diagram (I have circled them in blue in the first attached diagram). The second diagram is showing my proposed idea.



Hi Andrew,

Welcome to the forum!! :smiley:

Awesome project, I’m keen to hear about this!


The resistors on the logic level converter have some level of pullups kind of baked into them already!
It might be worth giving them a test both with and without - the only real thing you are fighting is the spec for the rise time; that’s no worries here though! (if the rise time is a bit slow you won’t break anything)

Here’s a clip from Colin’s Lab notes - awesome short clips about electronics!

EDIT: Neon lights they were aha, not sure how I missed that either!
Sparkfun have a great guide on getting it connected and some super interesting reading on how they work:

Let us know how you go!


Hi Andrew
I don’t know much about what you are trying to do with the camera.
BUT surely most of the connections on that logic level converter are all wrong. The only correct ones would be Ground and the yellow one whatever that is, bit hard to read.

HV connects to 5V source
LV connects to 3.3V source
These provide the 5V and 3,.3V supply for the outgoing signals.
HV 1, 2, 3 and 4 are connections for logic signals on the 5V side while LV 1, 2, 3 and 4 are ditto on the 3.3V side.

You seem to have 5VDC going in to HV3 and expect it to be 3.3VDC out at LV3. That is not going to happen. The 5V and 3.3V have to be provided at HV and LV externally.

Liam I don’t know how you did not pick up on this.
Cheers Bob


Hi Bob Andrew and Liam,

Good spot, Re: the connections!

Sometimes I2C connections also work at a logic level and supply voltage of 3.3v so you could try it without!


Could hardly miss it. Something like neon lights
Cheers Bob


Hi Bob,

Thank you for explaining that. I know it might be very obvious to people experienced with electronics, but I am an amateur, hence the reason I sought advice on this forum. I misread the description of bi-directional logic, I actually thought it converted the 5v to 3.3v.


Hi Andrew

No, not in the true sense. To do that there are dedicated 5V to 3.3V POWER converters. That is they will not only convert the voltage but will supply useful current or power as well.

The device you have only “shifts” the logic level from 5V to 3.3V and vice versa, it will not supply any useful current. It is what is known as a “high impedance” source. We know it is at least 10kΩ as there are 10kΩ resistors in series with it so it will only drive “high impedance” inputs which most logic devices are.

To the uninitiated this probably sounds pretty complicated but without going into the basics of Volts, Amperes, Watts and resistance I can’t think of an easy way to explain all of this. What I can suggest is if you are really interested is start getting some knowledge of the basics and you may find a lot of mysterious things will fall into place and understanding will become a whole lot easier… There used to be some analogies around which compared all of this with a header tank full of water for volts, a pipe to carry the water for wire conductors, the water flow representing current or amperes and a tap simulating resistance or impedance to the water flow for resistance in ohms (Ω) and maybe a water wheel to represent the work or power which can be obtained with the combination.

Cheers Bob