Hi there.

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.

Quote

qbunjo@printserver:~$ gpio readall
+-----+-----+----------+------+--Orange Pi Zero--+------+----------+-----+-----+
| H2+ | wPi |   Name   | Mode | V | Physical | V | Mode | Name     | wPi | H2+ |
+-----+-----+----------+------+---+----++----+---+------+----------+-----+-----+
|     |     |     3.3v |      |   |  1 || 2  |   |      | 5v       |     |     |
|  12 |   8 |    SDA.0 | ALT3 | 0 |  3 || 4  |   |      | 5V       |     |     |
|  11 |   9 |    SCL.0 | ALT3 | 0 |  5 || 6  |   |      | 0v       |     |     |
|   6 |   7 |   GPIO.7 |  OUT | 0 |  7 || 8  | 0 | ALT3 | TxD3     | 15  | 198 |
|     |     |       0v |      |   |  9 || 10 | 0 | ALT3 | RxD3     | 16  | 199 |
|   1 |   0 |     RxD2 | ALT3 | 0 | 11 || 12 | 0 | ALT3 | GPIO.1   | 1   | 7   |
|   0 |   2 |     TxD2 | ALT3 | 0 | 13 || 14 |   |      | 0v       |     |     |
|   3 |   3 |     CTS2 | ALT3 | 0 | 15 || 16 | 0 | ALT3 | GPIO.4   | 4   | 19  |
|     |     |     3.3v |      |   | 17 || 18 | 0 | ALT3 | GPIO.5   | 5   | 18  |
|  15 |  12 |     MOSI | ALT3 | 0 | 19 || 20 |   |      | 0v       |     |     |
|  16 |  13 |     MISO | ALT3 | 0 | 21 || 22 | 0 | ALT3 | RTS2     | 6   | 2   |
|  14 |  14 |     SCLK | ALT3 | 0 | 23 || 24 | 0 | ALT3 | CE0      | 10  | 13  |
|     |     |       0v |      |   | 25 || 26 | 0 | ALT3 | GPIO.11  | 11  | 10  |
+-----+-----+----------+------+---+---LEDs---+---+------+----------+-----+-----+
|  17 |  30 | STAT-LED |  OUT | 0 | 27 || 28 |   |      | PWR-LED  |     |     |
+-----+-----+----------+------+---+-----+----+---+------+----------+-----+-----+
| H2+ | wPi |   Name   | Mode | V | Physical | V | Mode | Name     | wPi | H2+ |
+-----+-----+----------+------+--Orange Pi Zero--+---+------+---------+-----+--+

 

I tried to push the values through "echo":

Quote

echo 7 > /sys/class/gpio/export

echo "out" > /sys/class/gpio/gpio7/direction

echo 1 > /sys/class/gpio/gpio7/value

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:

lsmod
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)

 

EDIT:

I changed the driving pin for pin9 and it works fine. Pin 7 is damaged or anything? Dunno.

I use the same gpio library and all pins are working on my OPi Zero.

It may be worth re-soldering pin 9 on the IDC header and see if the soldered

connection is at fault.

 

Below is  a very  quick bash script to set all pins as outputs, activate them,

then turn off all pins you can use as a check.

There's probably more efficient ways of doing the same thing

 

#!/bin/bash 
gpio reset; 
sleep 1; 
for n in {0..30}; 
do 
        gpio mode $n out;        
        gpio write $n on;        
done 
gpio readall 
sleep 3 
for n in {0..30}; 
do 
        gpio write $n off; 
done     
gpio readall; 
sleep 3;
gpio reset