This program is pretty simple. Whenever a user waves both hands across 2 PIR sensors, it should print out a message in console that displays which GPIO ports has being activated. The raspberry pi uses GPIO ports 4 and 17 to read data from the sensor.

I receive this error message whenever I try to print out displays the GPIO ports that has being activated.

enter image description here This is the error message.

Traceback (most recent call last):
  File "peter.py", line 27, in <module>
    print("GPIO pin %s is %s" % (sensor, new_state, sensor2, new_state2))
TypeError: not all arguments converted during string formatting

This is the code.

import RPi.GPIO as GPIO
import time

sensor = 4
sensor2 = 17
GPIO.setup(sensor, GPIO.IN, GPIO.PUD_DOWN)
GPIO.setup(sensor2, GPIO.IN, GPIO.PUD_DOWN)

previous_state = False
current_state = False

previous_state2 = False
current_state2 = False

while True:
    previous_state = current_state
    previous_state2 = current_state2
    current_state = GPIO.input(sensor)
    current_state2 = GPIO.input(sensor2)
    if current_state2==True and current_state != previous_state2 and previous_state                                                                                    ate==False:

        new_state = "HIGH" if current_state else "LOW"
        new_state2 = "HIGH" if current_state2 else "LOW"

        print("GPIO pin %s is %s" % (sensor, new_state, sensor2, new_state2))
  • the first thing I notice is this line seems incomplete if current_state2==True and current_state != previous_state2 and previous_st May 26, 2016 at 0:14
  • 3
    Your also passing 4 arguments to a print statement that expects only 2 May 26, 2016 at 0:36
  • @SteveRobillard So I should remove sensor and sensor2?
    – peter pan
    May 28, 2016 at 7:13
  • He meant your format string has only two %s. Add more %s or do two prints. One for sensor and one for sensor2.
    – PaulF8080
    May 28, 2016 at 15:06

1 Answer 1


The reason for the error is you have two format specifiers %s but are passing 4 values (sensor, new_state, sensor2, new_state2).

Change the last line form this:

print("GPIO pin %s is %s" % (sensor, new_state, sensor2, new_state2))

to this:

print("GPIO pin %s is %s" % (sensor, new_state))
print("GPIO pin %s is %s" % (sensor2, new_state2))

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