Hello,
I have a tricky wiring problem, I am making an Arduino Micro game controller for an art exhibition. I have designed the controller to house the Arduino Micro within the controller body. I have bought a really nice sturdy long cable to go from the controller to the computer (which will be hidden).

The problem I have is that the cable is 3 core and I need a 4 core cable to attach to the micro USB output of the Arduino Micro. I am wondering if there is a way for me to transfer the data of the controller to the computer through a 3 core cable.

The controller has an analog stick and a button so therefore the Arduino needs 5 inputs(GND,3V,A0,A1 and D12) so it dosent make sense to store the Arduino outside the controller.

I am wondering if there is a clever way of getting the information across with a 3 core cable. Any advice would be greatly appreciated. thank you.

 

Very briefly: put another MCU on the other end and use the UART; then translate the received data to the USB port on the non-controller MCU.

 

Just thinking: USB is two wire, the other two are power. You might not have any problem anyway.

 

Hi Yaakov, Thank you for your fast response.

I am still a bit confused. So I would have a MCU plugged into the computer, I would have the 3 core wire attached to the 3 ports that UART requires on the computer MCU. Then the wire would go from the computer into the controller, and then what ? The controller's MCU needs to be powered, but it also needs the 3 UART inputs.

 

Hi Yaakov, Thank you for your fast response.

I am still a bit confused. So I would have a MCU plugged into the computer, I would have the 3 core wire attached to the 3 ports that UART requires on the computer MCU. Then the wire would go from the computer into the controller, and then what ? The controller's MCU needs to be powered, but it also needs the 3 UART inputs.

No, I just failed reading comprehension. I didn’t realize you needed to power it on the same cable.
Is there some reason you can’t get a different cable? It would save a lot of trouble. There is no trick to using the two plus screen cable by just connecting it cleverly. Any approach that might work will require a lot more circuitry.

It would be possible, just a lot of work.

 

I see, I am using microphone cables as their feel and flexibility is amazing compared to other cables. I find that all the 4 core cables I have seen have been stiff construction cables, But I will continue to look. Thank you very much for your thoughts !

 

What computer are you using and what software will you be using to interface with the data from the controller?
Without that information I have no idea what to suggest.
There is a physical limit to the length and construction of USB cables and it is a serial interface, not a parallel one.
Have you considered using a wireless interface between the micro and computer.
This is probably not important but why are you using a Tiny and a Micro? Could you not just use the micro inside the controller?

 

How far away is the controller from the computer? And how much current will be drawn from the 3V and ground connection?

Have you considered re-purposing an Ethernet cable? Patch cables are more flexible than the microphone cables I have seen that my son’s band has.

There are four twisted pairs in the cable. One wire of the three pairs could be used for A0, A1 and D2. The other half of each pair can be used for ground which will help maintain signal integrity. The fourth pair can have its two wires paralleled and used for the 3V supply.

It depends on a few parameters, but I already asked about those in my first paragraph.

 

Here is an example of 4-core a microphone cablee. It has two twisted pairs usually used together for more noise rejection so has if there were only two cores. But you can find it pretty cheap and remove the connecters.

I am pretty sure you could find it locally.

 

Ive decided just to buy a quad core microphone cable, thank you Yaakov for the suggestion

 

Ive decided just to buy a quad core microphone cable, thank you Yaakov for the suggestion

That should work. Be sure to check the voltage you are getting on the controller end. The length of relatively high gauge wire could cause enough voltage drop to affect proper operation.