Make a program have the group ID you tell it for sending and receiving
with radio. A group is like a cable channel (a Calliope mini can only
send or receive in one group at a time). A group ID is like the cable
channel number.
If you do not tell your program which group ID to use with this function, it will figure out its own group ID by itself. If you load the very same program onto two different Calliope minis, they will be able to talk to each other because they will have the same group ID.
radio.setGroup(0);id is a number from 0 to 255.This function only works on the Calliope mini, not in browsers.
This program makes the group ID equal 128.
radio.setGroup(128)on data packet received, send number, send value, send string
radio