# Copyright (c) 2014 Adafruit Industries # Author: Tony DiCola # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. import sys import time import MPR121 print('MPR121 Capacitive Touch Sensor Test') # Create MPR121 instance. cap = MPR121.MPR121() # Initialize communication with MPR121 using default I2C bus of device, and # default I2C address (0x5A). On BeagleBone Black will default to I2C bus 0. if not cap.begin(): print('Error initializing MPR121. Check your wiring!') sys.exit(1) # Alternatively, specify a custom I2C address such as 0x5B (ADDR tied to 3.3V), # 0x5C (ADDR tied to SDA), or 0x5D (ADDR tied to SCL). #cap.begin(address=0x5B) # Also you can specify an optional I2C bus with the bus keyword parameter. #cap.begin(bus=1) # Main loop to print a message every time a pin is touched. print('Press Ctrl-C to quit.') last_touched = cap.touched() while True: current_touched = cap.touched() # Check each pin's last and current state to see if it was pressed or released. for i in range(12): # Each pin is represented by a bit in the touched value. A value of 1 # means the pin is being touched, and 0 means it is not being touched. pin_bit = 1 << i # First check if transitioned from not touched to touched. if current_touched & pin_bit and not last_touched & pin_bit: print('{0} touched!'.format(i)) # Next check if transitioned from touched to not touched. if not current_touched & pin_bit and last_touched & pin_bit: print('{0} released!'.format(i)) # Update last state and wait a short period before repeating. last_touched = current_touched time.sleep(0.1) # Alternatively, if you only care about checking one or a few pins you can # call the is_touched method with a pin number to directly check that pin. # This will be a little slower than the above code for checking a lot of pins. #if cap.is_touched(0): # print 'Pin 0 is being touched!' # If you're curious or want to see debug info for each pin, uncomment the # following lines: #print '\t\t\t\t\t\t\t\t\t\t\t\t\t 0x{0:0X}'.format(cap.touched()) #filtered = [cap.filtered_data(i) for i in range(12)] #print 'Filt:', '\t'.join(map(str, filtered)) #base = [cap.baseline_data(i) for i in range(12)] #print 'Base:', '\t'.join(map(str, base))