I am looking to connect a PIR motion sensor from adafruit (http://www.adafruit.com/products/189) to electric imp. The PIR sensor takes a 5V input that I see is available from VIN pin on the imp. When the PIR sensor detects motion it would output 5V. I wanted to check an electric imp Pin can be configured as an input to take the 5V output from PIR sensor and in turn read the digital state as 1.
Thanks in advance.
It’s much better if you convert the level of your signal to 3.3V.
You can use a simple resistor divider in this case, as you just need the sensor to pull up your pin.
Or you can use a level shifter based on a classic 74HC125 (with EO control) or 74HC4050.
Another good way it could be to implement a very low cost two way level shifter, using two resistors and a cheap FET like a BSS138. This is well described by the engineer that first designed it as level shifter for the I2C bus at Philips:
It’s the solution that we adopted for the Breakout&Shield for imp001 for example:
Thank for the info. all the 3 solutions are helpful.