====== GPIO ======
===== Basics =====
https://wiki.openwrt.org/doc/hardware/port.gpio
{{https://wiki.openwrt.org/_media/media/doc/hardware/gpio_high_low.png?direct&400 |}} ((Quelle: wiki.openwrt.org))
{{:bpi-r2:led.svg.png?direct&100 |}} ((Quelle: commons.wikimedia.org))
===== Pin define =====
{{:bpi-r2:bpi-r2_gpio.png|}}
image taken from bpi-r2 schematics
^ Sparefunction ^ Mainfunction ^ pin# ^ xxxxxxxxxxxxxxxxxxxxx ^ pin# ^ Mainfunction ^ Sparefunction ^
| | | | {{ :bpi-r2:gpio_farbig.png?nolink |}} | | | |
| - | 3V3 | 1 | ::: | 2 | 5V | - |
| I2C_SDA0 | GPIO 75 | 3 | ::: | 4 | 5V | - |
| I2C SCL0 | GPIO 76 | 5 | ::: | 6 | GND | - |
| PWM3 | GPIO 206 | 7 | ::: | 8 | GPIO 82 | UART1 TX |
| - | GND | 9 | ::: | 10 | GPIO 81 | UART1 RX |
| UART0 TX | GPIO 80 | 11 | ::: | 12 | UCTS1 / INT2 | GPIO 24 (*) |
| UART0 RX | GPIO 79 | 13 | ::: | 14 | GND | - |
| PWM2 | GPIO 205 | 15 | ::: | 16 | GPIO 25 / INT3 | URTS1 |
| - | 3V3 | 17 | ::: | 18 | GPIO 21 | PCM_TX |
| SPI0_MO | GPIO 56 | 19 | ::: | 20 | GND | - |
| SPI0_MI | GPIO 55 | 21 | ::: | 22 | GPIO 18 | PCM_CLK |
| SPI0_CK | GPIO 54 | 23 | ::: | 24 | GPIO 53 | SPI0_CSN |
| - | GND | 25 | ::: | 26 | GPIO 20 | PCM_RX |
| I2C_SDA1 | GPIO 57 | 27 | ::: | 28 | GPIO 58 | I2C_SCL1 |
| | GPIO 126 | 29 | ::: | 30 | GND | - |
| I2S0_BCK | GPIO 74 | 31 | ::: | 32 | GPIO 72 | I2S0_DATA_IN |
| I2S0_LRCK | GPIO 73 (?) | 33 | ::: | 34 | GND | - |
| I2S0_DATA | GPIO 49 (M) | 35 | ::: | 36 | GPIO 19 | PCM_SYNC |
| SPDIF_IN1 | GPIO 202 | 37 | ::: | 38 | INT0 | GPIO 22 (*) / PCM_RST_IN |
| - | GND | 39 | ::: | 40 | GPIO 200 | SPDIF_OUT |
| | | | ::: | | | |
| ^ main ^ spare ^
^ Pin 1 | 3V3 | - |
^ Pin 2 | 5V | - |
^ Pin 3 | GPIO 75 | I2C_SDA0 |
^ Pin 4 | 5V | - |
^ Pin 5 | GPIO 76 | I2C SCL0 |
^ Pin 6 | GND | - |
^ Pin 7 | GPIO 206 | PWM3 |
^ Pin 8 | GPIO 82 | UART1 TX |
^ Pin 9 | GND | - |
^ Pin 10 | GPIO 81 | UART1 RX |
^ Pin 11 | GPIO 80 | UART0 TX |
^ Pin 12 | Int2 | GPIO 24 (*) / UCTS1 |
^ Pin 13 | GPIO 79 | UART0 RX |
^ Pin 14 | GND | - |
^ Pin 15 | GPIO 205 | PWM2 |
^ Pin 16 | GPIO 25 / Int3 | URTS1 |
^ Pin 17 | 3V3 | - |
^ Pin 18 | GPIO 21 | PCM_TX |
^ Pin 19 | GPIO 56 | SPI0_MO |
^ Pin 20 | GND | - |
^ Pin 21 | GPIO 55 | SPI0_MI |
^ Pin 22 | GPIO 18 | PCM_CLK |
^ Pin 23 | GPIO 54 | SPI0_CK |
^ Pin 24 | GPIO 53 | SPI0_CSN |
^ Pin 25 | GND | - |
^ Pin 26 | GPIO 20 | PCM_RX |
^ Pin 27 | GPIO 57 | I2C_SDA1 |
^ Pin 28 | GPIO 58 | I2C_SCL1 |
^ Pin 29 | GPIO 126 | I2S0_MCLK
^ Pin 30 | GND | - |
^ Pin 31 | GPIO 74 | I2S0_BCK |
^ Pin 32 | GPIO 72 | I2S0_DATA_IN |
^ Pin 33 | GPIO 73 (?) | I2S0_LRCK |
^ Pin 34 | GND | - |
^ Pin 35 | GPIO 49 (M) | I2S0_DATA |
^ Pin 36 | GPIO 19 | PCM_SYNC |
^ Pin 37 | GPIO 202 | SPDIF_IN1 |
^ Pin 38 | INT0 | GPIO 22 (*) / PCM_RST_IN |
^ Pin 39 | GND | - |
^ Pin 40 | GPIO 200 | SPDIF_OUT |
(*) special GPIO need memory-patch and mode-set in 4.4.70
(?) currently not working
(M) mode-setting needed
===== Kernel 4.4.70 =====
==== Access standard GPIO ====
root@bpi-r2:~# GPIO=/sys/devices/platform/1000b000.pinctrl/mt_gpio
root@bpi-r2:~# echo "mode 25 0" >$GPIO #not needed for every GPIO
root@bpi-r2:~# echo "dir 25 1" >$GPIO
root@bpi-r2:~# echo "out 25 1" >$GPIO
works with LED on Pin 14 (-) and Pin 16 (+), incl. resistor (220 Ohm)
==== Access special GPIO ====
for the GPIOs 22/(23??)/24 it is neccessary to set a register (siehe [[https://github.com/BPI-SINOVOIP/BPI-R2-bsp/issues/17|issue#17]] comment #15) {{ :bpi-r2:gpioreg.tar.gz |mwrite}}
root@bpi-r2:~# ./mwrite /dev/mem 0x10005b10 0x00000038
./mwrite offset : 10005b10, val : 00000038
b6f03b10
root@bpi-r2:~# GPIO=/sys/devices/platform/1000b000.pinctrl/mt_gpio
root@bpi-r2:~# echo "dir 24 1" >$GPIO
root@bpi-r2:~# echo "out 24 1" >$GPIO
root@bpi-r2:~# echo "mode 24 0" >$GPIO
for GPIO24 (pin 12) i have to set mode to 0
===== Kernel 4.14 =====
GPIO_SYSFS and CONFIG_DEBUG_GPIO must be set in Kernel-Config (.config)
==== Access standard GPIO ====
root@bpi-r2# mount -t debugfs none /sys/kernel/debug
root@bpi-r2# cat /sys/kernel/debug/pinctrl/1000b000.pinctrl/gpio-ranges
GPIO ranges handled:
0: 1000b000.pinctrl GPIOS [232 - 511] PINS [0 - 279] #base=232, first value of GPIOS
root@bpi-r2# GPIO_NO=$((232+25)) #base + number of gpio
root@bpi-r2# echo $GPIO_NO
257
root@bpi-r2# echo $GPIO_NO > /sys/class/gpio/export
Pin 14=GND/16=GPIO25 (+)
=== GPIO as Output ===
root@bpi-r2# echo out > /sys/class/gpio/gpio${GPIO_NO}/direction
root@bpi-r2# echo 1 > /sys/class/gpio/gpio${GPIO_NO}/value
root@bpi-r2# echo 0 > /sys/class/gpio/gpio${GPIO_NO}/value
used for LED+resistor (220 Ohm) on Pin 14=GND/16=GPIO25 (+)
=== GPIO as Input ===
now try with high-active button-circuit on GPIO 200 (pin 40 between button and resistor, using pin 39 as GND [resistor] and pin 17 as 3v3-vcc)
[10:54] root@bpi-r2:~# echo in > /sys/class/gpio/gpio${GPIO_NO}/direction
[10:56] root@bpi-r2:~# cat /sys/class/gpio/gpio${GPIO_NO}/value
0 #button not pressed
[10:56] root@bpi-r2:~# cat /sys/class/gpio/gpio${GPIO_NO}/value
1 #button pressed
[10:56] root@bpi-r2:~# cat /sys/class/gpio/gpio${GPIO_NO}/value
0 #button not pressed
#check every 1/4s
watch -n 0.25 cat /sys/class/gpio/gpio${GPIO_NO}/value
==== Special GPIO ====
memory-hack (like in 4.4.70) not needed
here example for GPIO24 (pin12):
root@bpi-r2# GPIO_NO=$((232+24))
root@bpi-r2# echo $GPIO_NO > /sys/class/gpio/export
root@bpi-r2# echo out > /sys/class/gpio/gpio${GPIO_NO}/direction
root@bpi-r2# echo 1 > /sys/class/gpio/gpio${GPIO_NO}/value
LED becomes on :)
==== on-board LEDs ====
on-board leds used here are near the power-socket (not next to gpio)
http://forum.banana-pi.org/t/control-on-board-leds/4287/13
on =>
echo 1 > /sys/class/leds/bpi-r2:isink:green/brightness
off =>
echo 0 > /sys/class/leds/bpi-r2:isink:green/brightness
blink (creates delay_on/off-nodes for frequency) =>
echo timer > /sys/class/leds/bpi-r2:isink:green/trigger
change blink frequency (on and off time in ms) =>
echo 100 > /sys/class/leds/bpi-r2:isink:green/delay_on
echo 100 > /sys/class/leds/bpi-r2:isink:green/delay_off
in my tests, green is blinking by default (red+blue are simply on/off), i don't know how to disable blinking of green led
L=/sys/class/leds/bpi-r2\:isink
echo 0 > $L:red/brightness #goes off
echo 1 > $L:red/brightness #goes on
echo 0 > $L:green/brightness #goes off
echo 1 > $L:green/brightness #starts blinking
===== UART =====
==== change DTS(i) ====
with Kernel 4.4.x the DeviceTree-sections are missing, these can be copied from a newer Kernel (dtsi). in the *bpi*.dts or *bananapi*.dts set state to enabled
definitions in the mt7623.dtsi: http://elixir.free-electrons.com/linux/v4.13-rc7/source/arch/arm/boot/dts/mt7623.dtsi
now in bananapi.dts set "status=okay" for your desired uart
notice that in mt7623.dtsi first must come uart2 then the others, else after uboot-message "Starting Kernel" no more output is shown
Uart3 can be [[http://forum.banana-pi.org/t/gpio-uart-not-the-debug-port/3748/8|routed to UCTS2/URTS2]]. These ports are next to Debug-UART-connector ([[http://forum.banana-pi.org/t/gpio-uart-not-the-debug-port/3748/25|here]])
==== port preferences ====
#show preferences of serial port (replace ttyS2 with your port or ttyUSB0 if a USB2serial-adapter is used):
stty -F /dev/ttyS2 -a
#set speed to 9600 baud, 8 bits, 1 stop bit, no parity:
stty -F /dev/ttyS2 9600 cs8 -cstopb -parenb
#deactivate processing (character conversion,linebreaks,...)
stty -F /dev/ttyS2 -opost
#raw Modus
stty -F /dev/ttyS2 raw
==== Usage ====
pin 8/10 = uart1 (tx/rx) = 11003000
pin 11/13 = uart0 (tx/rx) = 11002000
#!/bin/bash
DEV=/dev/ttyS2
#stty -F ${DEV} sane
#stty -F ${DEV} 9600 cs8 -cstopb -parenb -crtscts -echo
stty -F ${DEV} 9600 cs8 -cstopb -parenb raw -echo
dmesg | grep "ttyS.*MMIO" | sed 's/^\[.*\] \(\d*.*\) at.*$/\1/'
echo "11002000 = uart0 (tx/rx) = pin 11/13"
echo "11003000 = uart1 (tx/rx) = pin 8/10"
echo "using $DEV"
echo "send data using \"echo \"AT\" >$DEV\""
while read line; do
# if [[ -n "$line" ]]; then
echo "["$(date "+%Y-%m-%d %H:%M:%S")"] received: "$line
# fi
done < <(cat $DEV)
echo "AT" >/dev/ttyS2
{{ :bpi-r2:uarttest.ino |simple example for Arduino (Nano)}}
{{:bpi-r2:uart-bpi.jpg?nolink&250}}
{{:bpi-r2:uart-levelshifter.jpg?nolink&150}}
{{:bpi-r2:uart-arduino.jpg?nolink&150}}
PI Levelshifter Arduino
1 (3V3) ------- LV HV -------- 5V
6 (GND) --------- GND --------- GND
8 (TX) ------- LV2 HV2 -------- RX
10 (RX) ------- LV1 HV1 -------- TX
===== PWM =====
kernel-option PWM_MEDIATEK must be set (module possible), depends on PWM(=y)
using gpio 206 (pin 7) as pwm3
echo 3 >/sys/class/pwm/pwmchip0/export
echo 200000 >/sys/class/pwm/pwmchip0/pwm3/period
echo 100000 >/sys/class/pwm/pwmchip0/pwm3/duty_cycle
echo 1 >/sys/class/pwm/pwmchip0/pwm3/enable
[[https://www.kernel.org/doc/Documentation/pwm.txt]]
period The total period of the PWM signal (read/write). Value is in nanoseconds and is the sum of the active and inactive time of the PWM.
duty_cycle The active time of the PWM signal (read/write). Value is in nanoseconds and must be less than the period.
period=200000ns=200ms=5kHz
duty_cycle=100000ns=1/2 period=50% high + 50% low Signal
currently output has the wrong frequency (1kHz instead of 5kHz) see [[http://forum.banana-pi.org/t/gpio-python-or-shell/3912/41|forum]] and [[https://github.com/frank-w/BPI-R2-4.14/issues/14|issue]]
2018-03-02: frequency is now right: [[https://github.com/frank-w/BPI-R2-4.14/commit/3a850c8f82519910703072736e6ffa7319ca5b0d|Commit in 4.14-main]]
===== SPI =====
http://forum.banana-pi.org/t/bpi-r2-spi-communication/4779/27
===== I2C =====
[[http://forum.banana-pi.org/t/has-anyone-added-an-rtc/5004|how to add a i2c RTC]]
apt-get install i2c-tools
in ubuntu 18.4 you need to add universe to /etc/apt/sources.list
[17:13] root@bpi-r2:~# modprobe i2c-dev
[17:14] root@bpi-r2:~# i2cdetect -y 0
added an rtc ds1307 (with removed pullups) to i2c0 (I2C_SDA0=pin3, I2C_SCL0=pin5, 5V=pin4, GND=pin6)
#!/bin/bash
modprobe i2c-dev
modprobe rtc-ds1307
echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-0/new_device
#cat /sys/class/i2c-dev/i2c-0/device/0-0068/rtc/rtc0/time
#read rtc
hwclock -r
#set system-clock to rtc-value
#hwclock -s
#set rtc to system-time
#hwclock -w
===== 1Wire =====
thanks to user [[http://forum.banana-pi.org/t/dallas-1-wire-on-bpi-r2-working/6254/18|phil from bpi-r2-forum]]
To enable w1-gpio on GPIO 19 add the following to the main node of mt7623n-bananapi-bpi-r2.dts
w1 {
pinctrl-names = “default”;
compatible = “w1-gpio”;
gpios = <&pio 19 0>;
status = “okay”;
};
{{ :bpi-r2:mt7623n-bananapi-bpi-r2_onewire.zip |dts for kernel 4.9 with 1wire-node}}
add settings to kernel config
CONFIG_W1=m
CONFIG_W1_MASTER_GPIO=m
CONFIG_W1_SLAVE_THERM=m
and recompile the kernel
Your devices should now show up at /sys/bus/w1/devices/
===== GPS-PPS =====
http://mtnstormdaq.com/blog/2012/10/gps-pps-use-as-a-time-reference/
[[http://forum.banana-pi.org/t/pps-gpio-working/6745|phil on bpi-r2-forum]] got pps working with kernel 4.9
[[https://learn.adafruit.com/adafruit-ultimate-gps|HW-module]]
adding this to main-section of mt7623n-bananapi-bpi-r2.dts:
pps {
pinctrl-names = “default”;
compatible = “pps-gpio”;
gpios = <&pio 72 0>;
status = “okay”;
};
{{ :bpi-r2:mt7623n-bananapi-bpi-r2_pps.zip |modified 4.9 dts}}
and add this options in the kernel-config for GPIO PPS support:
CONFIG_PPS=m
CONFIG_PPS_CLIENT_LDISC=m
CONFIG_PPS_CLIENT_GPIO=m
===== thermal =====
not really gpio, but i wont spend an own page
cat /sys/class/thermal/thermal_zone0/temp
http://forum.banana-pi.org/t/lm-sensors-support/4145/30