Imitation is …

… the sincerest form of flattery, so they say (at least, that is one of the things they say!)

Minolta DSC

Shown above is my auto-up windows & track mode DSC MINI circuit, below a newly designed “MCAW” circuit which provides similar features. I first learned of this new circuit a week or so ago, and chatted at length with the designer, Kevin. He was kind enough to send a circuit to me to review.

If you wonder whether Kevins MCAW is a “rip off” – NO!
What Kevin has done is taken my auto-up-windows MINI circuit as inspiration only; the MCAW does provide auto-up windows and can also provide “track mode DSC” or some forms of garage opener control.

From an engineering position, It is interesting to compare the new design with my original. I developed the MINI circuit to provide a solution to auto-up windows for myself and a couple of friends – and there was enough interest online to make a batch of nearly 30 circuits. After that, word-of-mouth (and a MotoringFile review) spread the word and more than 1000 now exist!
Kevin therefore has tried to design his circuit to reduce costs – something that was not a priority for me back when I was making a circuit for just a few people.

In the picture above, you can see that Kevin’s PIC (the “brains” of the circuit) is much smaller than the one in my original circuit – this provides a cost & size reduction but also forces a couple of design compromises.
The original MINI circuit PIC has a separate pin for each toggle switch signal, but Kevin has been forced to “double up” and share multiple inputs to pins. This gives some limitations in detecting switches, but if designed well the end user should not be affected.

More significantly, you can see that Kevin’s circuit has no ribbon cable – he identified this as a high cost labor-intensive part of my MINI circuit design, and was successful in finding an alternate solution – in the picture you can see the “back” of the MCAW, with a large black connector extending from it, and “bump pads” above and below. This connector pushes straight into the toggle switch panel connector (also visible), with the bump pads helping to ensure correct alignment. The original MINI wiring connector then pushes onto the pins on the “front” of the MCAW (seen in the first picture); there might be some concern over the weight of the MINI wiring harness pulling the MCAW out of the toggle switch panel (the original connector latches into place) – but my test indicates a firm grip which is unlikely to disconnect.

Another design change adopted by Kevin is that not all signals go “straight through” – this was a design requirement of my original design, so that any failure of the circuitry would still allow all toggle switch connections to work. With Kevins design, failure of the MCAW electronics will prevent closing the windows. However as Kevin discussed, electronics is generally very reliable.

Finally, Kevin has chosen to provide no protective coating to the circuit (every original MINI circuit is Humiseal coated to protect it from moisture / dust / etc) – this may be a perfectly acceptable design decision, but it is not one I would make!

I have only tested Kevins circuit on my MINI circuit bench test rig, not in my car (I already have auto-up windows in GBMINI!); I found it to work as advertised, and easy to initially set up, although it I found it confusing to reprogram functions – the circuit has many modes and you click a switch repeatedly to move from mode to mode; what I could not figure is how to get from the current MCAW configuration to the new one – do I restart from 0 or do I count from the current mode? Neither answer seemed to work reliably for me.
I also found that cancelling the auto-up by clicking the window down switch was not reliable – not sure why.

For me, the MCAW is more “geeky” than the MINI circuit – and that is not meant to be a negative. Notice that the MCAW has socketed parts – this allows the purchaser to replace parts and change the functionality!

So which circuit should you buy?
Today, the MINI circuit is temporarily unavailable – I am still working on a solution for that.
The MCAW seems to provide similar features to my original, and is offered at a slightly lower price point.
I believe the original MINI circuit is more suitable for people needing the garage opener functionality – there is more flexibility in my design.
The MCAW offers a couple of features (such as closing both windows from one switch) which are not standard on my MINI circuit (but only one person ever wanted that feature!)
The original MINI circuit has proven itself with more than 1000 circuits “out there” and lots of feedback; presumably the MCAW will establish itself in the coming months …