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Rotary Trinkey Schematic
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Rotary Trinkey Schematic

by rybec on Thu May 13, 2021 6:37 pm

TL;DR: I can't find a schematic for the Rotary Trinkey, and I would really like one.


A week or so ago, I discovered the Neo Trinkey. I love the idea, but the only use cases I can find for it other than a smart flashlight don't work with the LEDs soldered directly to the board. (I do plan on using it for educational stuff for my kids, once it is back in stock though. They love the idea of smart flashlights.) I need the board to be in a different place in my projects from where the LEDs are, due to space and aesthetic considerations. So, I submitted a product suggestion for a generic Trinkey without the Neo, so I can use it with whatever I want and connect components to the Trinkey with wires instead of having them soldered to the board. (And I hope this is still being considered or perhaps has even been accepted.) The truth is, the tiny form factor of the Neo Trinkey is perfect for a lot of things. The problem is, very few of those things involve LEDs directly soldered to the board.

Now, in an attempt to find a way to use the Neo Trinkey without having to wait for a new product to be designed that might not even happen, I did some research that led me to the Neo Trinkey schematic on Adafruit Learn. My hope was to figure out exactly what the SWC and SWD pads on the bottom are for, and the schematic and some more research revealed that I can probably use those pads for GPIO, so long as one is treated carefully on reboot to prevent the chip from going into debug mode. It's not a perfect solution, but it gives me one solid GPIO (as much as I would get with the Neo Pixels removed) and another that just can't be used for input during boot. It was more than I had hoped for, but the schematic did reveal some room for improvement, in the form of a lot of unused pins on the microcontroller.

Today, I discovered the Rotary Trinkey. It's a little wider than the Neo, but it would still work for some of my uses. With only one capacitive touch input, it won't work for the main use, but maybe another pin can be used for a second one. And, in addition to the one capacitive touch input and the SWC and SWD pads, it has five pins available. I could do some I2C or SPI with that and still have up to three pins left over, opening the way for far more advanced things than I had previously been considering! It could be my lucky day, except that I can't find a schematic or a Learn page for it, so I don't know how those pins are mapped. It seems to have been designed exclusively for a rotary encoder, without any concern for the fact that people might want to use it for something else. Indeed, the through holes for the rotary encoder aren't even marked with pin numbers on the silkscreen (which could be a problem when reading the schematic, depending on how it is laid out). I would really like to know which pins those are connected to on the chip. Actually, what I really want to know is what functions are available to those pins on the microcontroller, so I understand my options before deciding whether or not to buy one or more (and, it would be nice to not have to determine which hole goes to which pin by trial and error). I have the Neo Trinkey schematic, so if I even knew what pins those holes mapped to, I could use that for comparison (for example, I know what pins the Neo is using for capacitive touch), and I am sure I can find the datasheet for the ATSAMD21E18 microcontroller. If only I could find a schematic for the Rotary Trinkey, maybe I could use it for all sorts of things it was never designed for, at least, until/unless my request for a generic Trinkey becomes a real product.


I do hope to eventually see a generic Trinkey the same size as the Neo Trinkey, with a handful of pads or through holes, perhaps laid out in a grid (4x4 maybe; I just counted, and the microcontroller does have enough pins, though I think half of them would have to be pads rather than through holes, to accommodate the MC and other components; routing on such a small board might make only 2x4 feasible, but that's still 8 GPIOs on such a tiny board), mapped to various pins and two capacitive touch inputs like what the Neo Trinkey has, but if I can get a link to the schematic for Rotary Trinkey, it might be a perfect start for some of the projects where size is a little more flexible.
rybec
 
Posts: 14
Joined: Fri May 09, 2014 12:15 pm

Re: Rotary Trinkey Schematic

by blnkjns on Fri May 14, 2021 12:14 am

Can't find the schematics in the Adafruit repo yet. Maybe it is too new, but they might add it if they see this.
If it is a rotary combined with an M0, it must be 3 generic digital I/O pins all with interrupt capability. You also have 2 solder islands for testing purposes. If you swipe to all ports with some code while treating it as a ItsyBitsy M0 I guess you will quickly identify the 5 ports.

Have you looked at the Digispark? It may fullfill your needs. The board is very simple though, only 512bytes of RAM.

Adafruit itself only has a USB-C variation:
https://www.adafruit.com/product/4514
Please make this board with M4 and direct USB contacts on the PCB! Oh and remove the castelated pins. That is another 1+1mm saved and we won't solder any boards on when inserted in a laptop.

blnkjns
 
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Re: Rotary Trinkey Schematic

by rybec on Fri May 14, 2021 5:25 am

Oh right, two of them are probably 5V and ground. (I don't have much experience with rotary encoders, but that should have been obvious.) 512 bytes would work for some of my projects, but the 32KB of the ATSAMD21 is really attractive. It's enough to use many of the LCD screens on Adafruit. Those aren't a high priority, but that significantly expands the possibilities. I also like the price point of the Trinkeys. And yeah, the castellated pins add even more width.

But yeah, I am hoping this will motivate them to get the schematics on the Adafruit repo or on Learn. I don't even see a new product video on the Rotary Trinkey. I'm not sure, but that may mean it is incredibly new. The Neo Trinkey only came out a few weeks ago. I wonder if this came out after that.
rybec
 
Posts: 14
Joined: Fri May 09, 2014 12:15 pm

Re: Rotary Trinkey Schematic

by rybec on Fri May 14, 2021 3:50 pm

Yep, the page now has the New Products video it was introduced in, which was aired only two days ago. So this is indeed newer than the Neo Trinkey. So hopefully the schematic is posted somewhere soon!
rybec
 
Posts: 14
Joined: Fri May 09, 2014 12:15 pm

Re: Rotary Trinkey Schematic

by adafruit_support_carter on Tue May 18, 2021 2:36 pm

They'll be available eventually. Same for all the Trinkey's. Just can take some time to get everything uploaded and linked. Keep an eye on the product page and they should be added there at some point.

adafruit_support_carter
 
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Re: Rotary Trinkey Schematic

by rybec on Tue May 18, 2021 2:53 pm

Will do. I've got the product pages for all four Trinkey's open in by browser, and I am checking multiple times a day!
rybec
 
Posts: 14
Joined: Fri May 09, 2014 12:15 pm

Please be positive and constructive with your questions and comments.