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en:bpi-r2:gpio [2019/01/09 18:04] – external edit 127.0.0.1en:bpi-r2:gpio [2023/04/08 15:08] – [Basics] frank
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 +====== 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     |
 +| | |   | ::: | | | |
 +
 +<hidden>
 +|         ^ 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 |
 +</hidden>
 +  (*) 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 ====
 +<code bash>
 +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" >$GPIO
 +</code>
 +works with LED on Pin 14 (-) and Pin 16 (+), incl. resistor (220 Ohm)
 +
 +==== Access special GPIO ====
 +for the GPIOs 22/(23??)/24 it is neccessary to set a register (siehe [[https://github.com/BPI-SINOVOIP/BPI-R2-bsp/issues/17|issue#17]] comment #15) {{ :bpi-r2:gpioreg.tar.gz |mwrite}}
 +
 +<code bash>
 +root@bpi-r2:~# ./mwrite /dev/mem 0x10005b10 0x00000038
 +./mwrite offset : 10005b10, val : 00000038
 +b6f03b10
 +root@bpi-r2:~# GPIO=/sys/devices/platform/1000b000.pinctrl/mt_gpio
 +root@bpi-r2:~# echo "dir 24 1" >$GPIO
 +root@bpi-r2:~# echo "out 24 1" >$GPIO
 +root@bpi-r2:~# echo "mode 24 0" >$GPIO
 +</code>
 +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 ====
 +
 +<code bash>
 +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 $GPIO_NO > /sys/class/gpio/export
 +</code>
 +
 +Pin 14=GND/16=GPIO25 (+)
 +
 +=== GPIO as Output ===
 +<code bash>
 +root@bpi-r2# echo out > /sys/class/gpio/gpio${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
 +</code>
 +
 +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)
 +
 +<code bash>
 +[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${GPIO_NO}/value
 +</code>
 +==== Special GPIO ====
 +
 +memory-hack (like in 4.4.70) not needed
 +
 +here example for GPIO24 (pin12):
 +
 +<code bash>
 +root@bpi-r2# GPIO_NO=$((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
 +</code>
 +
 +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
 +
 +<code>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</code>
 +===== 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 ====
 +
 +<code bash>
 +#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
 +</code>
 +
 +
 +==== Usage ====
 +
 +  pin 8/10 = uart1 (tx/rx) = 11003000
 +  pin 11/13 = uart0 (tx/rx) = 11002000
 +
 +<code bash>
 +#!/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)
 +</code>
 +<code bash>
 +echo "AT" >/dev/ttyS2
 +</code>
 +
 +
 +{{ :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}}
 +
 +<code>
 +PI             Levelshifter       Arduino
 +1 (3V3)  -------  LV   HV -------- 5V
 +6 (GND)  ---------  GND  --------- GND
 +8 (TX)   ------- LV2  HV2 -------- RX
 +10 (RX)  ------- LV1  HV1 -------- TX
 +</code>
 +===== PWM =====
 +
 +kernel-option PWM_MEDIATEK must be set (module possible), depends on PWM(=y)
 +
 +using gpio 206 (pin 7) as pwm3
 +<code>
 +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
 +</code>
 +
 +[[https://www.kernel.org/doc/Documentation/pwm.txt]]
 +<code>
 +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.
 +</code>
 +<code>
 +period=200000ns=200ms=5kHz
 +duty_cycle=100000ns=1/2 period=50% high + 50% low Signal
 +</code>
 +
 +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]]
 +
 +<code>apt-get install i2c-tools</code>
 +in ubuntu 18.4 you need to add universe to /etc/apt/sources.list
 +
 +<code>
 +[17:13] root@bpi-r2:~# modprobe i2c-dev                                         
 +[17:14] root@bpi-r2:~# i2cdetect -y 0
 +</code>
 +
 +added an rtc ds1307 (with removed pullups) to i2c0 (I2C_SDA0=pin3, I2C_SCL0=pin5, 5V=pin4, GND=pin6)
 +
 +<code>
 +#!/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
 +</code>
 +
 +===== 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
 +
 +<code>
 +w1 {
 +   pinctrl-names = “default”;
 +   compatible = “w1-gpio”;
 +   gpios = <&pio 19 0>;
 +   status = “okay”;
 +}; 
 +</code>
 +
 +{{ :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:
 +
 +<code>
 +pps {
 +   pinctrl-names = “default”;
 +   compatible = “pps-gpio”;
 +   gpios = <&pio 72 0>;
 +   status = “okay”;
 +}; 
 +</code>
 +{{ :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
en/bpi-r2/gpio.txt · Last modified: 2023/06/08 17:06 by 127.0.0.1