Hi there, im working on with sparkfun OpenPIR sensors. According to the hookup guide https://learn.sparkfun.com/tutorials/op … okup-guide
I had received like some unknown characters.
Followed the guide and use 115200 baud. Halp 
Hi yu1928,
That is a weird little error here. Can you please provide a bit more information about your setup? What type of microcontroller are you using with the OpenPIR and what version of Arduino are you using? Also, try adjusting the code to set the serial baud rate to 9600 and adjust the monitor as well, that may help here.
Hi thanks for the reply,
Current setup according to the tutorial
Arduino uno Wifi Rev2
Tried changing the code to 9600 baud and it works.
Just a question, the difference between 115200 and 9600 rate does it affect input speed or is there any difference between using any of them?
Read up the common baud rate is 9600 but still have no clue on the difference thank you
Interesting. Are you by chance using either WiFi to transmit the serial data or a very long USB cable (eg. 6+ feet)? Faster baud rates can drop some data when you are using a long USB cable or wireless communication. If you want to learn more about baud rates, the [Wikipedia page for them goes into some good details on them and how they work.](Baud - Wikipedia)
Nope, transmit the serial through usb A to usb B cable . 1.6meters ( 5+feet)