About the pin configuration for motors (from https://www.npmjs.com/package/pi-gpio)
This couldn't have been more confusing. Raspberry Pi's physical pins are not laid out in any particular logical order. Most of them are given the names of the pins of the Broadcom chip it uses (BCM2835). There isn't even a logical relationship between the physical layout of the Raspberry Pi pin header and the Broadcom chip's pinout. The OS recognizes the names of the Broadcom chip and has nothing to do with the physical pin layout on the Pi. To add to the fun, the specs for the Broadcom chip are nearly impossible to get!
This library simplifies all of this (hopefully), by abstracting away the Broadcom chip details. You only need to refer to the pins as they are on the physical pin layout on the Raspberry PI. For your reference, the pin layout follows. All the pins marked "GPIO" can be used with this library, using pin numbers as below.
| P1 - 3.3v | 1 | 2 | 5v |
| I2C SDA | 3 | 4 | -- |
| I2C SCL | 5 | 6 | Ground |
| GPIO | 7 | 8 | TX |
| -- | 9 | 10 | RX |
| GPIO | 11 | 12 | GPIO |
| GPIO | 13 | 14 | -- |
| GPIO | 15 | 16 | GPIO |
| -- | 17 | 18 | GPIO |
| SPI MOSI | 19 | 20 | -- |
| SPI MISO | 21 | 22 | GPIO |
| SPI SCLK | 23 | 24 | SPI CE0 |
| -- | 25 | 26 | SPI CE1 |
| Model A+ and Model B+ additional pins | |||
| ID_SD | 27 | 28 | ID_SC |
| GPIO | 29 | 30 | -- |
| GPIO | 31 | 32 | GPIO |
| GPIO | 33 | 34 | -- |
| GPIO | 35 | 36 | GPIO |
| GPIO | 37 | 38 | GPIO |
| -- | 39 | 40 | GPIO |
That gives you several GPIO pins to play with: pins 7, 11, 12, 13, 15, 16, 18 and 22 (with A+ and B+ giving 29, 31, 32, 33, 35, 37, 38 and 40). You should provide these physical pin numbers to this library, and not bother with what they are called internally. Easy-peasy.