実際のところ
PythonのGPIOコマンドを使おうとする場合、
raspbian組み込みの以下のコマンドでピン状況をみる
$ gpio readall
+-----+-----+---------+------+---+---Pi 3+--+---+------+---------+-----+-----+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
| | | 3.3v | | | 1 || 2 | | | 5v | | |
| 2 | 8 | SDA.1 | IN | 1 | 3 || 4 | | | 5v | | |
| 3 | 9 | SCL.1 | IN | 1 | 5 || 6 | | | 0v | | |
| 4 | 7 | GPIO. 7 | IN | 1 | 7 || 8 | 1 | ALT5 | TxD | 15 | 14 |
| | | 0v | | | 9 || 10 | 1 | ALT5 | RxD | 16 | 15 |
| 17 | 0 | GPIO. 0 | IN | 0 | 11 || 12 | 0 | IN | GPIO. 1 | 1 | 18 |
| 27 | 2 | GPIO. 2 | IN | 0 | 13 || 14 | | | 0v | | |
| 22 | 3 | GPIO. 3 | IN | 0 | 15 || 16 | 0 | IN | GPIO. 4 | 4 | 23 |
| | | 3.3v | | | 17 || 18 | 0 | IN | GPIO. 5 | 5 | 24 |
| 10 | 12 | MOSI | IN | 1 | 19 || 20 | | | 0v | | |
| 9 | 13 | MISO | IN | 1 | 21 || 22 | 0 | IN | GPIO. 6 | 6 | 25 |
| 11 | 14 | SCLK | IN | 1 | 23 || 24 | 1 | IN | CE0 | 10 | 8 |
| | | 0v | | | 25 || 26 | 1 | IN | CE1 | 11 | 7 |
| 0 | 30 | SDA.0 | IN | 1 | 27 || 28 | 1 | IN | SCL.0 | 31 | 1 |
| 5 | 21 | GPIO.21 | IN | 1 | 29 || 30 | | | 0v | | |
| 6 | 22 | GPIO.22 | IN | 1 | 31 || 32 | 0 | IN | GPIO.26 | 26 | 12 |
| 13 | 23 | GPIO.23 | IN | 0 | 33 || 34 | | | 0v | | |
| 19 | 24 | GPIO.24 | IN | 0 | 35 || 36 | 0 | IN | GPIO.27 | 27 | 16 |
| 26 | 25 | GPIO.25 | IN | 1 | 37 || 38 | 1 | IN | GPIO.28 | 28 | 20 |
| | | 0v | | | 39 || 40 | 1 | IN | GPIO.29 | 29 | 21 |
+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+-----+-----+---------+------+---+---Pi 3+--+---+------+---------+-----+-----+||<
全部のピンにアクセスする
readallコマンドは通常アクセスのピンをボード種類に合わせて表示します。
一方、allreadallコマンド*1では、産業用で使われるCompute Moduleの規格でアクセスできる外部ピン全てを表示できます。
$ gpio allreadall
+-----+------+-------+ +-----+------+-------+
| Pin | Mode | Value | | Pin | Mode | Value |
+-----+------+-------+ +-----+------+-------+
| 0 | IN | High | | 27 | IN | Low |
| 1 | IN | High | | 28 | IN | High |
| 2 | IN | High | | 29 | OUT | Low |
| 3 | IN | High | | 30 | ALT3 | Low |
| 4 | IN | High | | 31 | ALT3 | Low |
| 5 | IN | High | | 32 | ALT3 | High |
| 6 | IN | High | | 33 | ALT3 | High |
| 7 | IN | High | | 34 | ALT3 | Low |
| 8 | IN | High | | 35 | ALT3 | High |
| 9 | IN | High | | 36 | ALT3 | High |
| 10 | IN | High | | 37 | ALT3 | High |
| 11 | IN | High | | 38 | ALT3 | High |
| 12 | IN | Low | | 39 | ALT3 | High |
| 13 | IN | Low | | 40 | ALT0 | Low |
| 14 | ALT5 | High | | 41 | ALT0 | Low |
| 15 | ALT5 | High | | 42 | ALT0 | Low |
| 16 | IN | Low | | 43 | ALT0 | Low |
| 17 | IN | Low | | 44 | IN | High |
| 18 | IN | Low | | 45 | IN | High |
| 19 | IN | Low | | 46 | IN | High |
| 20 | IN | High | | 47 | OUT | High |
| 21 | IN | High | | 48 | ALT0 | Low |
| 22 | IN | Low | | 49 | ALT0 | High |
| 23 | IN | Low | | 50 | ALT0 | High |
| 24 | IN | Low | | 51 | ALT0 | High |
| 25 | IN | Low | | 52 | ALT0 | High |
| 26 | IN | High | | 53 | ALT0 | High |
+-----+------+-------+ +-----+------+-------+
"gpio: command not found"なら、wiringPiを入れ忘れてる
$ gpio readall
-bash: gpio: command not found
などと、コマンドが見つからない等々と出た場合、wiringPiが入ってません。
$ sudo apt-get install wiringpi