PropShield Compatibility

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Experimentalist

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Is there a full list of which Teensy micro controllers are directly compatible with the PropShield? That is that can be directly connected by adding pin headers and plugging straight in in a stack formation like the example below.

propshield_headers.jpg

My Guess is:
Teensy LC
Teensy 3.2
Teensy 4.0
Teensy 4.1
Teensy 3.5
Teensy 3.6

Is that correct?
 
It depends on exactly what you want to use in the prop shield.

With the exception of the back row of pins, all of the pins of the prop shields mate directly onto the 28 outer row pins on the Teensy LC, 3.0, 3.1, 3.2, and 4.0, and to the first 28 pins on the Teensy 3.5, 3.6, or 4.1. The only back row pin that the prop shield uses is the DAC (digital to audio converter) that can be used to play sounds when feed through an amplifier.

There are several things grouped together in the prop-shield(s):
  • 8 megabytes of flash memory;
  • Amplifier for sound from the DAC;
  • Level shifting for pins 11/13 to drive WS2812B/SK6812 (neopixel) or APA102 (dotstar) LEDs;
  • I2C support for motion sensors (on the prop shield with motion sensor obviously, and not the LC prop sensor).

All Teensies will support the flash memory directly.

For the amplifier, the Teensy LC, 3.1, and 3.2 will support it directly as the DAC pin lines up. The Teensy 3.5 and 3.6 will support it if you run a wire from A21 to the DAC pin on the shield. The Teensy 3.0, 4.0 and 4.1 do not have a DAC. If you are going to use the audio libraries to play sounds, note that the audio library doesn't support the Teensy LC. Note, the DAC has a different pin number (A12 on the LC, A14 on the 3.1/3.2, and A21 on the 3.5/3.6).

For the level shifting, all Teensys will support it. If you intend to use SPI displays, you might have do special code to switch between optimized display usage and using pins 11/13 for driving the LEDs. If you use it on the Teensy 4.0 or 4.1, pin 7 is normally used for I2S1, which means you probably can't combine the prop shield and audio shields. If you are just driving WS2812B/SK6812 LEDs, the Teensy LC already has a level shifter for pin 17/A3.

Here is the code from KurtE if you do need to switch between optimized displays and level shifting on a 3.1, 3.2, 3.5, or 3.6:

All Teensies will support the motion sensing, though I don't recall if the Teensy LC has enough memory to be able to run the motion sensing library.
 
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