Physical Construction Of Dongle - giokincade/autolocator GitHub Wiki

We're ready for the physical construction of the dongle that will plug into the "EXT CLOCK" input of the MTR90mk2. It uses a Honda 25L connector. For now, we're not using the SD card and don't need the lights. (Maybe we use a clear case for production or something.) But the basic idea is something like this:

This is what the back of the machine and the connector look like:

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So inside the box will be the Espruino Wifi 30mm x 23mm (1.2 x 0.9 inch). Read the full specs here.

And there's also little "chiclet" proto-board that contains the 24V => 5V regulator and the transistor switcher for the tach input. NOTE: The 5V supply for the transistor MUST BE SUPPLIED FROM ESPRUINO. Like, it can not be supplied by the 5V coming off the regulator, otherwise, we can NOT debug using USB. Which is a problem. So the idea is to power the Espruino from the Otari or USB, and then to power the transistor tach-switching circuit from the Espruino.

For this version, we will use hook up plugs and won't solder directly to Espruino, because we are probably going to fuck up. Also, given that it's not going to move, like ever at all, the flexibility is way more important than stability. Which doesn't matter.

Here is the pinout FROM the EXT CLOCK Honda connector. The 5V is wrong-- it's actually 24V. I won't know why they say its not.

The way we did the hookup with the Arduino was as follows. It may not be exactly the same, which is why we're not soldering to the Espruino. But it should be similar. The important part is that the tach pulse and possibly tach direction be available on the interrupt pins.

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For reference, the box we are using is 3.3" X 2.2" X 1.04", so it should fit fine in the Otari if the plug is in the center of the spine, as per initial sketch.

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NOTE FOR YOUR BOY JIMTRONIX:

When you solder the Honda to the little plugs, it would be great for you to label the plug side with the pin number of the Honda connector. You might need a really little paint pen or something but otherwise, it's gonna be a bitch to figure out which is which. If you do it while you're soldering it will be way easier. Also, maybe you have a better idea about how to keep track but we def should.