需要使用gpio readall命令来读取gpio信息：
reddy@reddy-pi:~/test$ gpio readall
+—–+—–+———+——+—+—Pi 2—+—+——+———+—–+—–+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+—–+—–+———+——+—+—-++—-+—+——+———+—–+—–+
| | | 3.3v | | | 1 || 2 | | | 5v | | |
| 2 | 8 | SDA.1 | ALT0 | 1 | 3 || 4 | | | 5V | | |
| 3 | 9 | SCL.1 | ALT0 | 1 | 5 || 6 | | | 0v | | |
| 4 | 7 | GPIO. 7 | IN | 1 | 7 || 8 | 1 | ALT0 | TxD | 15 | 14 |
| | | 0v | | | 9 || 10 | 1 | ALT0 | RxD | 16 | 15 |
| 17 | 0 | GPIO. 0 | IN | 0 | 11 || 12 | 1 | OUT | 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 | 1 | IN | GPIO. 5 | 5 | 24 |
| 10 | 12 | MOSI | ALT0 | 1 | 19 || 20 | | | 0v | | |
| 9 | 13 | MISO | ALT0 | 0 | 21 || 22 | 0 | IN | GPIO. 6 | 6 | 25 |
| 11 | 14 | SCLK | ALT0 | 0 | 23 || 24 | 1 | OUT | CE0 | 10 | 8 |
| | | 0v | | | 25 || 26 | 1 | OUT | 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 | 1 | OUT | GPIO.27 | 27 | 16 |
| 26 | 25 | GPIO.25 | IN | 0 | 37 || 38 | 0 | IN | GPIO.28 | 28 | 20 |
| | | 0v | | | 39 || 40 | 1 | OUT | GPIO.29 | 29 | 21 |
+—–+—–+———+——+—+—-++—-+—+——+———+—–+—–+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+—–+—–+———+——+—+—Pi 2—+—+——+———+—–+—–+
如上面的信息中：
RST = 24
DC = 23
这个数字是BCM列对应的数字，并非物理上的数字编号！！！切记！
raspi-config—>Advanced Options—>SPI
raspi-config—>Advanced Options—>I2C
