gen2thomas

Thanks! Unfortunatelly it is not working for me. But with the tag "tinkerboard-2" now I can found more information in the forum and stay up to date.

I have done some investigation and it looks a little bit different, but it seems there is the same behaviour for character device and sysfs. If all features are off (i2c1, uart etc.) the following header pins act fine as output: 3, 5, 7, 19, 21, 22, 23, 24, 26, 27, 28, 31 not working as output, current state in round brackets: 8 (1), 10 (1), 11 (0), 12 (1), 13 (1), 15 (1), 16 (0), 18 (0), 29 (0), 32 (1), 33 (1), 35 (0), 36 (1), 37 (1), 38 (1), 40 (0) Thats the reason why my initial test with pin 36 is not working and pin 26 has worked.

@usual user thanks for the fast reply, but therefore I have also tested sysfs and the "wait" option. Today I found my fault: It seems the used 1kOhm resistor together with the meter was not strong enough to override the internal resistors. The default internal resistor setup is possibly different between the Kernels. Using a LED show the correct behavior. Today I have also used another pin (header26, asus251, chip8-line3), so I will double check this.

Hello, is there an armbian available for Tinkerboard 2 (RK3399)? Mainly I need to setup a headless system with working i2c, pwm and gpio . Thanks!

Hi, I have installed "Armbian_22.08.7_Tinkerboard_bullseye_current_5.15.74_minimal.img.xz" on a Tinkerboard (no S, with RK3288). I have tried to set the output of some header pins without success. I used both "sysfs" and "gpiod" (which uses char-devices). Test procedure, e.g. for pin 36 (gpio223): # echo "223" > /sys/class/gpio/export # cat /sys/class/gpio/gpio223/direction in # cat /sys/class/gpio/gpio223/value 0 # echo "out" > /sys/class/gpio/gpio223/direction # cat /sys/class/gpio/gpio223/direction out # echo "1" > /sys/class/gpio/gpio223/value # cat /sys/class/gpio/gpio223/value 0 # echo "0" > /sys/class/gpio/gpio223/value # cat /sys/class/gpio/gpio223/value 0 The example is for the pin36 is grounded by an resistor with 1kOhm. If the resistor is switched to 3.3V all read values are go to "1". The read values match the measured voltage (~0V for "0", ~3.3.V for "1"). The same behaviour for "gpioset 7 7=0". After this, the "gpioinfo 7" lists the line as output, like expected. Only the voltage remain unchanged (gpioget will change the line to input). With TinkerOS the same test is working (with sysfs only, because old Kernel 4.4.). Afterwards I have also tested some (or all) different options, like "sudo gpioset -m wait -D push-pull -B pull-down gpiochip7 7=0". But no success. Have I something missed to set up in the device tree? I have enabled i2c1 & i2c4 and disabled all other features (uart, spi and w1-gpio etc.) by usage of armbian-config. Thanks for your help in advance