读取多个树莓派输入引脚的脚本

Question

I am using Raspberry pi 3 Model B+ and Python 3 for script.

I have 16 IR Sensors connected at board pins - Pin # (7, 11, 13, 15, 16, 18, 22, 29, 31, 32, 33, 35, 36, 37, 38, 40)

Whenever any IR sensors receives an input it should add up 1 in the existing counter. Also even multiple sensors triggers at same time - It should add the correct result.

I have written python3 script to read for one pin. Whenever pin detects the object it adds up 1 in the counter.

Also I have multiple raspberry pi boards. I am taking their Serial ID as the unique ID.

Can you help me to understand/write for multiple sensors at same time.

Code Snippet:

import RPi.GPIO as GPIO
import time

sensor_list = [7, 11, 13, 15, 16, 18, 22, 29, 31, 32, 33, 35, 36, 37, 38, 40]

#print("IR Sensor Ready.....")
#print("..STATRED..")
sensor = 16
count_object = 0


def get_serial():
    # Extract serial from cpuinfo file
    cpuserial = "0000000000000000"
    try:
        f = open('/proc/cpuinfo','r')
        for line in f:
            if line[0:6]=='Serial':
                cpuserial = line[10:26]
        f.close()
    except: cpuserial = "ERROR000000000"
    return cpuserial

raspberry_serial = get_serial()

try:
    while sensor:
        GPIO.setmode(GPIO.BOARD)
        GPIO.setup(sensor,GPIO.IN)
        if GPIO.input(sensor):
            count_object+=1
            print(f"Total Objects: {count_object} counter on {raspberry_serial} for the sensor id {sensor}")
            while GPIO.input(sensor):
                time.sleep(0.2)
        else:
            pass
except KeyboardInterrupt:
    GPIO.cleanup()

Answer 1

I have suggested a few changes to your core loop as I will describe. I haven't tested it.

• pin setup done once rather than on each loop.
• catch and report import errors
• on each loop, read each input and increment count for any with a high signal, then sleep

I don't exactly understand what you are trying to measure or your particular timing requirements so I made it read all inputs every 0.2 seconds. I am continuing in your style of polling for pin changes. However depending on how your sensor behaves this might either count a single event multiple times or miss events entirely. You might want to consider triggering off of transition events if that is appropriate. Also be sure to check whether your sensor requires a pull down.

I simply printed the counts. You can format it to include your board id in whatever way you require.

import time
try:
    # According to docs the import may raise an exception
    import RPi.GPIO as GPIO
except RuntimeError:
    print("Error importing RPi.GPIO!  This is probably because you need superuser privileges.  You can achieve this by using 'sudo' to run your script")
    raise

sensor_list = [7, 11, 13, 15, 16, 18, 22, 29, 31, 32, 33, 35, 36, 37, 38, 40]

try:
    # Initial setup for all pins only needs to be done once.
    GPIO.setmode(GPIO.BOARD)
    GPIO.setup(sensor_list, GPIO.IN)
    # A separate counter initially zero for each input pin.
    counts = { ch: 0 for ch in signal_list }
    while True:
        # flag changes in order to only report results when an event is detected
        detected = False
        for ch in signal_list:
            if GPIO.input(ch):
                detected = True
                counts[ch] += 1
        if detected:
            print(counts)
        # if an event remains high for more than 0.2 sec it might
        # be counted again on the next loop. Likewise if an event
        # comes and goes before the next loop it will be missed.
        time.sleep(0.2)

finally:
    GPIO.cleanup(sensor_list)