I use Orange Pi zero as home print server. It works for few months for now and I am very pleased with that. Although, my printer falls into deep sleep after printing (it's Brother HL-1110EW) and cannot be woken up by the server. I have to start printer manually to print next printouts. Thus I wanted to install tea4cups to drive a relay turning the printer on and off when needed.
I installed the WiringOP-zero (from here: https://github.com/xpertsavenue/WiringOP-Zero) but then strange things become to happen. I connected temporarily a LED diode to indicate the changes of the GPIO. (GPIO-7 and GND). The LED is on all the time, no matter what command I send.
Even if "gpio readall" shows "0" state on GPIO-7 the led still is on.
I tried to push the values through "echo":
But also without success. That means gpio readall still shows changes in the table but there are no physical changes on the pin (the voltage still is on).
Then I thought that maybe there is no kernel module loaded, but I can see that w1-gpio is loaded:
Module Size Used by
aes_arm_bs 20480 2
crypto_simd 16384 1 aes_arm_bs
ccm 20480 6
xradio_wlan 110592 1
mac80211 532480 1 xradio_wlan
sun4i_gpadc_iio 16384 0
cfg80211 491520 2 mac80211,xradio_wlan
industrialio 53248 1 sun4i_gpadc_iio
zram 24576 2
sun8i_thermal 16384 0
sunxi_cedrus 32768 0
rfkill 20480 3 cfg80211
libarc4 16384 1 mac80211
v4l2_mem2mem 20480 1 sunxi_cedrus
videobuf2_dma_contig 20480 1 sunxi_cedrus
videobuf2_memops 20480 1 videobuf2_dma_contig
videobuf2_v4l2 20480 2 sunxi_cedrus,v4l2_mem2mem
videobuf2_common 40960 3 sunxi_cedrus,v4l2_mem2mem,videobuf2_v4l2
w1_gpio 16384 0
wire 32768 1 w1_gpio
cn 16384 1 wire
uio_pdrv_genirq 20480 0
uio 16384 1 uio_pdrv_genirq
cpufreq_dt 20480 0
usb_f_acm 20480 1
u_serial 24576 3 usb_f_acm
g_serial 16384 0
libcomposite 45056 2 g_serial,usb_f_acm
ip_tables 24576 0
x_tables 24576 1 ip_tables
autofs4 36864 2
pwrseq_simple 16384 1
sunxi 16384 0
phy_generic 20480 2 sunxi
Then I started to read forums, including this one. Still no clue what is happening, I did not find any similar case.
I run out of ideas -maybe anyone would have some?
Oh, I forgot one thing that may be interesting - driving onboard red led actually works. (gpio 30)
I changed the driving pin for pin9 and it works fine. Pin 7 is damaged or anything? Dunno.