Prop Shield Compatible with Teensy 3.6?

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gabeschine

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I haven't been able to find any information about this online, yet.

I'm wondering if the Teensy 3.6 and the Prop Shield are pin compatible. I plan on using the shield's SD card, accel/gyro, and possibly the level-shifted outputs to drive APA102s (do I have to supply my own 5V power for that? Could it be, say, 4.8V instead?).

Any guidance would be appreciated. Thank you.
 
The first 1.4" of the T_3.6 matches pin for pin on the outside edge 28 pins - The Prop shield was tested in Beta to work. There can be pin conflicts depending on other active devices/uses, but that applies to T_3.2 as well.

The Prop shield doesn't include an SD adapter? The SD adapter on the main T_3.6 will work - it is wired directly to a 4 pin parallel SDIO interface and that isn't yet drop in compatible with existing SD. IIRC- I saw that recently Paul intends to get the SD sample updated soon to allow it to work on the T_3.6.

4.8V should work - that depends on your strip. I only tested on a DotStar strip powered from USB (T_3.2 and T_3.6/T_3.5) - which may or not be all of 5V under load. If not the same power to the Teensy - it must at least safely share a common ground I expect.
 
Yes and no.

The main pins that the prop shield uses are the same:
  • Ground (on main row)
  • Pin 2 (i2c interrupts)
  • Pin 5 (audio enable)
  • Pin 6 (flash memory chip select)
  • Pin 7 (LED chip select)
  • Pin 11 (LED data, but also MOSI)
  • Pin 13 (LED clock, but also SCLK)
  • Pin 18 (i2c SDA)
  • Pin 19 (i2c SCL)
  • 3.3v voltage (on main row)
  • Analog ground
  • VIN

However, the DAT pin for playing sounds is in a different location (A21), and you would need to use a wire to connect it.

The other pins in that back row (secondary 3.3v, secondary ground, program, and Vbat for the real-time clock) are also in a different location, and if you use a header to access those pins, you would need to connect those wires as well. Those pins + the reset pin are in the new row of pins in the middle next to the micro sd card.

I've used the prop shield on my Teensy 3.6, though I forgot to hook up the DAT to A21, and I did not hear sounds coming out :rolleyes:

There are three caveats I've found so far:
  • When you are doing the orientation setup for the motion sensors, the code writes to EEPROM locations 76 through 127 to store the orientation information. The current Teensydunio 1.31 beta 1 does not support writing to EEPROM at speeds of more than 120 Mhz. So, you need to either reduce your speed to 120 Mhz, or lookup defragster's patches to eeprom.c and usb_desc.c;
  • I used FrankB's TeensyTransfer to transfer .mp3 files to the flash memory. I found that it would glitch every so often, and I had the best luck, power cycling the Teensy, and transferring one file at a time (of course, I need to add the DAT wire tonight to make sure the sound plays);
  • On the Teensy 3.2, I would tend to mount the prop shield underneath the Teensy 3.2 (and mount a feather adapter on top). If you want to use the Teensy in a breadboard setup, you need to mount the prop shield on top of the Teensy, so that the additional 20 pins can be plugged into the breadboard (or on female headers on a perf board). However, if you mount the Prop Shield on top of the Teensy, it becomes hard to push the program button.
 
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Right brain fart: of course the SD on the T3.6 is what I plan on using. Not sure why I mentioned it.

OK, so yes I will have to find new pins for various IO I'm doing so as not to conflict with the prop shield, but that's OK. Good to know that the outside pins are compatible and that will allow the Prop Shield to work. Thank you.

I've driven APA102's all the way down to 3.3v, and they work fine. You just have to slow down the data rate to compensate for it. I was wondering more about the level shifter on the shield, if it would just shift up to whatever voltage I provide on the 5v input. I might even just give the 5v input the same as my vbatt since I don't have much space in my install for a beefy boost regulator.
 
gabeschine said:
Right brain fart: of course the SD on the T3.6 is what I plan on using. Not sure why I mentioned it.

OK, so yes I will have to find new pins for various IO I'm doing so as not to conflict with the prop shield, but that's OK. Good to know that the outside pins are compatible and that will allow the Prop Shield to work. Thank you.

I've driven APA102's all the way down to 3.3v, and they work fine. You just have to slow down the data rate to compensate for it. I was wondering more about the level shifter on the shield, if it would just shift up to whatever voltage I provide on the 5v input. I might even just give the 5v input the same as my vbatt since I don't have much space in my install for a beefy boost regulator.
Click to expand...

I've had problems getting the level shifter to work with the Adafruit ST7735 driver (but I suspect this happens on the 3.2 as well). If I'm not trying to use both the ST7735 and the LEDs, the level shifter works fine on the 3.6 (assuming you set pin 7 HIGH when doing the LEDs and turning it off afterwards).

You DO NOT WANT to hook up Vbat on the Teensy to high voltage. That pin is meant for coin batteries to power the real time clock when the rest of the Teensy is not powered. You can fry your Teensy if you feed it more than 3v (or 3.3v -- I don't remember if it can go to 3.3v, or if it just wants 3v).

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If you've not used the prop shield before, note that the 8 output pins of the prop shield do not line up with 0.1" spacing, so you won't be able to hook straight pins to a perfboard (assuming you are mounting the prop shield on the bottom). Instead you need to connect either wires or right angle headers to the 4 pins on each side. I've found that if I hook up wires to the pins, that they will eventually break, and I will have to de-solder the stub and resolder it, so I now use right angle female headers.
 
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FrankB designed the following board that converts between the DAT pin and the pins on the cross row from the 3.5/3.6 location to the 3.2 location, so that you can use 3.2 shields like the prop shield, feather adapter, etc. easier:
 
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