ultimarc u-track not wired properly for minipac could blow the board

[chucklepie]

Hello,
I've got a u-track which was bought to go with the minipac and a minipac with the optical and button harnesses.

When I look at the wiring diagram, as attached,  Y axis for the trackball is brown/orange and X axis is yellow/green. Spinner is blue/purple. When I look at my minipac harness it does indeed have these coloured wires in the right place.

However, when I look at my u-track it has green/yellow on one plug (X) but on the other (Y) it is using blue/purple.

So, if I connect the plugs from the mini-pack harness to the matching colours on the plugs from the u-track I'd end up with trackball X and spinner connected, however the spinner is wired differently so it would end up with ground/5v being pushed through the minipac on the wrong pins.

I think I'll hold off and ring when they're open to make sure but I think it's completely and utterly stupid that they wire the u-track with the wrong colours and you could end up blowing the minipac, unless somebody can tell me differently?

[PL1]

As long as you don't have 5v and ground reversed/shorted, you won't hurt it.

Optical inputs won't hurt each other if you get them mixed up.

Worst thing that will happen is that the cursor will move on the wrong axis or the wrong direction.

If it moves in the wrong direction, swap the 2 optical input wires and that will fix it.


Scott

[chucklepie]

From a 5v point of view it looks ok as pin 1 is 5v for trackball and spinner but ground is not, so I think plugging in to match the colours would end up sending the track ball X1 to ground. Is this safe? I have no idea.

What I'm saying is if your average person connected the u-track up to the harness they'd match the colours and it wouldn't work, possibly shorting something out (I'm no electrician I guess ground is safe). So you'd expect Ultimarc to wire the u-track to match the minipac harness?

[PL1]

Both axis grounds are connected to each other inside the UTrak.

On mine, one connector (yellow/green) has a black ground wire, the other (blue/purple) doesn't.

Both connectors have a 5v (red) connection.

Total of 7 wires.


Scott

[chucklepie]

That's right, but ground is different on the minipac for spinner/trackball so using the wrong plug could cause spinner x1 going to ground.

If that's harmless it's fine. All I'm saying is why on earth do they colour the wiring diagram with one set of colours but following the diagram you'd end up doing it wrong.

Surely it doesn't take a rocket scientist to realise that they should wire the Y axis from the u-track in orange/brown and not purple/blue (which is spinner colours) so it's both easy to figure out (X axis is yellow/green which matches from u-track to harness to minipac) and matches the diagram and you don't end up plugging the u-track into the spinner slots by mistake and grounding the data cable?

[PL1]

5v and ground should be on the outside.

Sounds like you ran into the same harness wiring mixup that I had at first -- two similar colored wires that were reversed -- black and purple IIRC.

The harness is easy to reconfigure, so that's what I did with certain wires.


Scott

EDIT:  Now that I look closer at this, I realize that the harness came wired as advertised -- it is a flaw in design and/or execution, depending on how you look at it.

Andy should probably consider:
1. Slapping his designers/beta testers for designing/not noticing the different arrangement of pins on UTrak + Spintrak.    50 lashes with a wet noodle!   

2. Getting the right color wires (orange/brown) for x-axis on the next batch of UTraks.  The UTraks shipped with the mini-USB encoder are already connected when they ship IIRC so it makes sense to align the UTrak wire colors to the Mini-Pac harness that customers will need to connect.

[chucklepie]

It's thicker cable on the u-track, maybe he had more purple than brown

Would be nice if they posted connection instructions on the website though.

[PL1]

Thanks, Chucklepie.   

This thread got me digging into the harness again and I realized that my trackball X-axis inputs were actually on the spinner input pins. 

Swapped them and the trackball appears to be working even better now. 

I'd better fire up some Marble Madness and Millipede to be sure.   


Scott

[chucklepie]

Glad to be of service

I got a swift reply from Andy at Ultimarc and he says he'll be wiring up trackballs with the proper colours on his next batch.

My next problem is the switches 

I bought 14 Happ buttons and 4 IL buttons to go with the minipac and minipac harness I bought. All the harnesses come with 4.8 mm female spade connectors and guess what, 14 of the switches have 2.8mm spade connectors meaning I'll either have to squash them all in with pliers and hope they work or cut them and put new ones on. This isn't ideal of course as I spent a fair bit of money on the full harness kit and was told they would all fit. Hopefully they swap out my switches...

Or has somebody got a better/easier way of getting the spades to fit?

Presumably the 4 IL buttons came with the 4.8mm spades and the happ with 2.8mm.