PI4J - pin.high() not working

[Greenberet]

Hello,

I'm trying to set the pin state of the gpio04 pin to high, but it will always be low =(.

in /sys/class/gpio a folder for gpio23 (which is 04) gets created correctly. However /sys/class/gpio/gpio23/value has always the value 0.
When I set it manually ( echo "1" > /sys/class/gpio/gpio23/value ) my led will glow correctly.

I'm using the following code as root:

Code: Select all

//...
    GpioController gpio = GpioFactory.getInstance();
    GpioPinDigitalOutput pin = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, "MyLED", PinState.LOW);
//...
    pin.high() //  /sys/class/gpio/gpio23/value is still 0

Am I missing something?

[rpdom]

Which actual physical pin are you using?

The internal gpio 23 (Broadcom/BCM) is connected to Physical pin 16 on the P1 connector and in "wiringpi" terms is known as "GPIO. 4".

When using the /sys/class/gpio interface you are using the BCM numbers.

When connecting to the board you use the actual physical pin numbers.

The "wiringpi" numbers exist in a different universe.

[DougieLawson]

The "wiringpi" numbers exist in a different universe.

At least with wiringpi you can ask it to display all the possible names and numbers for the pins.

Code: Select all

pi@apollo:~$ gpio readall
 +-----+-----+---------+------+---+--B Plus--+---+------+---------+-----+-----+
 | 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 | 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 | ALT0 | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO | ALT0 | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK | ALT0 | 0 | 23 || 24 | 1 | ALT0 | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | ALT0 | 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 | 0 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 0 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+--B Plus--+---+------+---------+-----+-----+
pi@apollo:~$

[Greenberet]

I know that they are different.

the GPIO_04 should match bcm-gpio23 which is fine. When I open the port the /sys/class/gpio23 folder gets created(no other gpio folders are visible) and I'm running a simple watch --interval=1 "cat /sys/class/gpio/gpio23/value" to check the result, and it is always 0. So it isn't a wiring problem.