“AlarmPi is an alarm system ESP - Raspberry Pi - Telegram based.
As you can see in the explanatory pic:
The ESP module works as device for reading the sensor (in this case, for motion detecting by the PIR).
After reading, it sends a message to the Raspberry Pi local server (step 1 - 2).
Raspberry server, only intercept this message and send it to you through Telegram (step 3 - 4).
Then you will receive message on your own chat (step 5).”