Teensy 3.6 -> Feather Board Orientation

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willyman

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I'm ready to attach the 3.6 to the Feather board adapter, but I want to make sure I have the orientation right before I solder.

I checked out the schematic for the adapter board and it wasn't particularly clear:
https://raw.githubusercontent.com/a...-3.x-Feather-Adapter-PCB/master/schematic.png

Comparing the schematic to the 3.6 pinout I saw a potential conflict, but it might be me reading the schematic incorrectly:

Is there a pin conflict with Analog Ground and Vin?

Here is the Orientation of the 3.6 that I think is right, but I want to make sure:

I can remove the Lipo battery connector on the adapter board for the teensy. Should the yellow pins be connected as well?

The blue pins- looking at the pinout of the 3.6, it appears these pins are N/C, and just there for mechanical purposes- is that correct?

Thanks for any help, I wanted to consult more experienced folks before soldering and making it significantly more difficult reverse
 
The Yellow pins include A11 and A10, which are shown as not connected and Aref, which is connected but will only be doing things if your code actually switches to external reference https://www.arduino.cc/reference/en/language/functions/analog-io/analogreference/

The vertical blue row of pins include power and ground which should already be connected but suggest checking that both gnd and 3.3V are common on the feather board, if so leave them be. There is also program and real time clock battery input which I do not believe is doing anything here. The one that may be is A14/DAC. The schematic shows it going of to do 'something' so you would need to check what that is, and then look at if you would actually need that pin for your code. If you do the T3.6 has the DAC on side row, so you would need to run an L shaped jumper to reach there.

Socketing the two together may be helpful, as may swapping your stacking order around to put Teensy at the bottom. If you hide the program button you will be OK as long as your code does not end up breaking the remote reset cycle at some point in which case you need access to the blue row of pins and trigger program from there.
 
There are several ways to attach things, it depends on what you want to do.

You could mount the Teensy 3.{5,6} on top of the feather adapter. Note in doing so, you will need to mount the Teensy up high enough so that it clears the lipo connector. Here you would typically use normal female headers on the 28 pins for the normal Teensy holes on the adapter, and put male headers on the Teensy. This would allow you to remove the Teensy from the feather board, and plug it straight into a breadboard.

You might/might not want to hook up DAC0 (next to pin 39) to the pin in the back that is A14 on the Teensy 3.2 if you want to have the DAC output (pin left #4 on the feather adapter). I'm not sure any of the feather wings use the DAC output, since the AVR boards don't have it.

You also might/might not want to hook up the program pin to the corresponding pin on the feather shield. Or you might want to hook up reset instead. Many of the feather wings bring out that button, and it can be useful if the button can't be accessed from the Teensy (particularly if you mount the Teensy under the Feather adapter.

If you want to use feather wings mounted on top of the Teensy, you would need to mount double height female headers, so you can mount the feather wing. Alternatively, buy one of the feather doubler or tripler shields, and mount the Teensy on top, and put male headers in the feather adapter. Then mount female headers on both/all of the doubler/tripler shields, mounting the Teensy in one position, and the feather wing(s) in the other.

Alternatively, you can mount the Teensy underneath the feather adapter. There the issue is access to the program button, and whether you can use the micro-SD card easily. But in this orientation, you can use normal female headers for the feather part, and mount the wings on top of the adapter.

FrankB designed a Teensy adapter, that adapts the Teensy 3.5/3.6 middle pins to the Teensy 3.2 layout for use in things like the feather adapter:
 
Ok awesome thank you for your excellent reply!!

I'm definitely going to socket them, good idea. The feather adapter will be plugging in to this 3.5" TFT display:
https://www.adafruit.com/product/3651

So for the moment I'm only concerned with the pins that this display requires. I already have the display working with the feather, but the refresh is way too slow. Even when doing intelligent display updates. I'm using the display to print from an ADC. Here's the format:

I only redraw the digits that have changed, and I only redraw one digit at a time. The same digit is printed in background color then the new digit is printed. Even so the feather has too slow of spi speed to have smooth display updates.

Looking at the guide for the display, it looks like I'll only need these pins:


Maybe I should wire them with jumper wires first before soldering in the header pins
 
MichaelMeissner said:
There are several ways to attach things, it depends on what you want to do.

You could mount the Teensy 3.{5,6} on top of the feather adapter. Note in doing so, you will need to mount the Teensy up high enough so that it clears the lipo connector. Here you would typically use normal female headers on the 28 pins for the normal Teensy holes on the adapter, and put male headers on the Teensy. This would allow you to remove the Teensy from the feather board, and plug it straight into a breadboard.
Click to expand...
I think this is what I'm going to do. I'm considering removing the lipo connector and extending it with wires to a more accessible location. That would make for a clean flatter install on the adapter board
You might/might not want to hook up DAC0 (next to pin 39) to the pin in the back that is A14 on the Teensy 3.2 if you want to have the DAC output (pin left #4 on the feather adapter). I'm not sure any of the feather wings use the DAC output, since the AVR boards don't have it.
Click to expand...
Got it thanks, good call.

You also might/might not want to hook up the program pin to the corresponding pin on the feather shield. Or you might want to hook up reset instead. Many of the feather wings bring out that button, and it can be useful if the button can't be accessed from the Teensy (particularly if you mount the Teensy under the Feather adapter.
Click to expand...
If I bring these pins out to my own buttons, do you switch reset and program to ground or to 3V3?

FrankB designed a Teensy adapter, that adapts the Teensy 3.5/3.6 middle pins to the Teensy 3.2 layout for use in things like the feather adapter:
Click to expand...
I've only had the teensy for a day so far, so I'm not sure I completely understand what Franks board is doing. Which pins on the teensy are being relocated to where?

Thanks a bunch
 
willyman said:
I
I've only had the teensy for a day so far, so I'm not sure I completely understand what Franks board is doing. Which pins on the teensy are being relocated to where?

Thanks a bunch
Click to expand...

It allows a Teensy 3.5/3.6 to be plugged into a Teensy 3.2 shield, mapping the 5 pins in the Teensy 3.2 back row (Vbattery, 3.3v, Ground, Program, DAC) into the equivalent pins on the 3.5/3.6. It also connects the 3.3v and ground pins that are at position 15 (i.e. just after the classical 14 pins of the Teensy 3.2). Finally, it brings A10, A11, AREF out to the front, in case you are mounting the prop shield (which does not have the Vusb, A10, A11, AREF pins).
 
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