Added script for MODBUS device search

tests/find_address.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+from time import sleep
+from sys import exit
+import minimalmodbus
+import serial
+
+
+print('---- Looking for device ----')
+slave_address_list = range(1,256)
+CO2_addr = 9
+total_devices = 0
+for slave_address in slave_address_list:
+    print(f'Address {slave_address}:\t', end='')
+    try:
+        # modbus init
+        instrument = minimalmodbus.Instrument('/dev/rs485', slave_address, close_port_after_each_call=True)  # port name, slave address (in decimal)
+        instrument.serial.baudrate = 115200
+        instrument.serial.bytesize = 8
+        instrument.serial.parity   = serial.PARITY_EVEN
+        instrument.serial.stopbits = 1
+        instrument.serial.timeout  = 0.05          # seconds
+        instrument.mode = minimalmodbus.MODE_RTU   # rtu or ascii mode
+        instrument.clear_buffers_before_each_transaction = True
+        ##
+        CO2 = instrument.read_register(CO2_addr, 1, functioncode=4) * 10
+        print('DEVICE RESPONDED')
+        total_devices += 1
+    except minimalmodbus.NoResponseError:
+        print(f'no response')
+    sleep(0.1)
+print(f'Found {total_devices} devices (tried {len(slave_address_list)} addresses)')
+print('---- DONE ----')
+exit(0)