This project allows to control a total of 16 GPIO by USB. It can simultaneously read and write up to 8 predefined Teensy GPIO using the low level GPIO Teensy registers:
GPIOX_PDOR: for writing the GPIO.GPIOX_PDIR: for reading the GPIO.
The current implementation uses the first 8 bits of the GPIOD
register for writing, and the first 8 bits of the GPIOC for
reading.
The relationship between the physical pins and register numbers is
available on the Teensy schematic (see the docs directory).
| Register Number | Register | Pin Number (physical) |
|---|---|---|
| 0 | C | 15 |
| 1 | C | 22 |
| 2 | C | 23 |
| 3 | C | 9 |
| 4 | C | 10 |
| 5 | C | 13 |
| 6 | C | 11 |
| 7 | C | 12 |
| -- | --- | -- |
| 0 | D | 2 |
| 1 | D | 14 |
| 2 | D | 7 |
| 3 | D | 8 |
| 4 | D | 6 |
| 5 | D | 20 |
| 6 | D | 21 |
| 7 | D | 5 |
- Bit-wise operations in C: https://www.pjrc.com/teensy/pins.html
- Low-level register for I/O: https://forum.pjrc.com/archive/index.php/t-17532.html