OwnerPython has the pretty good library “WiringPi-Python“, but it depends on WiringPi2 for Raspberry Pi and cannot be installed automatically through pip. Here is a solution.
In my project I want to control a battery voltage and a charging state for my LiPo battery. Therefore I’ve added the ADS1115 board.
I’ve installed WiringPi2 for BPi and tried to read analog inputs through the gpio command line utility.
1 | $ gpio -x ads1115:200:0x48 aread 200 |
The main disadvantage of this method for me is the default analog reading settings: 128 samples per second and +/-4.096V range (my battery voltage is 4.2V). You cannot change these setting in the command line utility.
1 2 3 4 5 6 7 8 9 10 | $ sudo apt install swig $ cd ~/ $ mkdir BPI-WiringPi2 $ cd BPI-WiringPi2 $ git clone https://github.com/BPI-SINOVOIP/BPI-WiringPi2.git $ mkdir WiringPi-Python $ cd WiringPi-Python $ git clone https://github.com/WiringPi/WiringPi-Python.git $ mv /home/pi/WiringPi-Python/WiringPi /home/pi/WiringPi-Python/WiringPi_old $ nano setup.py |
; change the string (add a new include directory)
include_dirs=['WiringPi/wiringPi','WiringPi/devLib'],
to
include_dirs=['WiringPi/wiringPi','WiringPi/devLib', 'WiringPi/wiringPi/board'],
1 2 | $ sudo ln -s /home/pi/BPI-WiringPi2 /home/pi/WiringPi-Python/WiringPi $ sudo python3 setup.py install |
The corresponding Python script:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | #!/usr/bin/env python3 import wiringpi pin_base = 0x200 i2c_addr = 0x48 wiringpi.wiringPiSetup() wiringpi.ads1115Setup(pin_base, i2c_addr) # 0 - +/-6.144V range = Gain 2/3 = 1 bit = 1.875mV # 1 - +/-4.096V range = Gain 1 = 1 bit = 1.25mV wiringpi.digitalWrite(pin_base +0, 0) # 0 - 8 samples/s # 1 - 16 samples/s # 4 -128 samples/s # look at wiringPi\ads1115.h for other constants wiringpi.digitalWrite(pin_base +1, 0) # read pin 0 value = wiringpi.analogRead(pin_base + 0) print("CH0: {}".format(value)) value = wiringpi.analogRead(pin_base + 1) print("CH1: {}".format(value)) value = wiringpi.analogRead(pin_base + 2) print("CH2: {}".format(value)) value = wiringpi.analogRead(pin_base + 3) print("CH3: {}".format(value)) |
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