netmon-multinode/RasPi/MultiNode.py

144 lines
4.6 KiB
Python

from enum import IntEnum
from pyblake2 import blake2s
from pyLoraRFM9x import LoRa, ModemConfig
import time, toml, math, struct
HASH_LENGTH = 8
class MessageType(IntEnum):
DeviceStatus = 1
SensorStatus = 2
Time = 2
class MultiNode:
sensor_type_table = {1: "V", 2: "mA"}
def __init__(self):
with open("Config.toml", "r") as config_file:
config = toml.loads(config_file.read())
print(config)
self.server_address = config["server"]["address"]
self.server_secret_key = config["server"]["secret_key"]
# How often to send the time
self.time_interval = config["server"]["time_interval"]
self.devices = {}
self.last_time_message = time.time()
self.lora = LoRa(
0, # SPI channel
25, # Interrupt pin
255, # Node ID
reset_pin=22,
modem_config=ModemConfig.Bw125Cr45Sf128,
tx_power=14,
freq=868,
acks=False) # , receive_all=True)
self.lora.cad_timeout = 1
self.lora.on_recv = self.process_packet
self.lora.set_mode_rx()
def loop(self):
if time.time() - self.last_time_message > self.time_interval:
self.send_packet(0xFFFF, int(MessageType.Time).to_bytes(1, "little"))
self.last_time_message += self.time_interval
#print("Sent time")
def decode_packet(self, device, data):
packet_type = data[0]
# match packet_type:
# case MessageType.DeviceStatus:
if packet_type == MessageType.DeviceStatus:
device["status"] = {"battery": struct.unpack('<f', data[1:5])[0], "temperature": struct.unpack('<f', data[5:10])[0]}
return device["status"]
if packet_type == MessageType.SensorStatus:
channels_raw = struct.unpack('<H', data[1:3])[0]
channels = []
for i in range(16):
if (channels_raw >> i) & 1:
channels.append(i)
sensor_data = []
for i in range(len(channels)):
offset = i * 6
sensor_data.append({"channel": channels[i], "type": data[3 + offset], "pin": data[4 + offset], "value": struct.unpack('<f', data[5 + offset:9 + offset])[0]})
device["sensors"] = sensor_data
return sensor_data
def process_packet(self, payload):
rx_id = int.from_bytes(payload.message[0:2], byteorder="little")
tx_id = int.from_bytes(payload.message[2:4], byteorder="little")
msg_id = int.from_bytes(payload.message[4:8], byteorder="little")
length = payload.message[8]
data = payload.message[9:9 + length]
data_hash = payload.message[9 + length:9 + length + HASH_LENGTH]
if len(payload.message) != length + 9 + HASH_LENGTH:
print(f"Invalid length! Expected {length + 9 + HASH_LENGTH} actual {len(payload.message)}")
return
hash_function = blake2s(key=0x0.to_bytes(8, "little"), digest_size=8)
hash_function.update(payload.message[:-HASH_LENGTH])
if hash_function.digest() != data_hash:
print(f"Hash doesn't match! Expected {hash_function.digest()} got {data_hash}")
return
if not tx_id in self.devices:
self.devices[tx_id] = {}
self.devices[tx_id]["last_message_id"] = msg_id
self.decode_packet(self.devices[tx_id], data)
# RSSI cahnges from -13 to -27 on change from +20 to +2 dBm TX setting
# print(f"{tx_id} #{msg_id}: {self.decode_packet(self.devices[rx_id], data)} V, {payload.rssi} dB(?) RSSI, {payload.snr} dB(?) SNR {(time.clock_gettime_ns(0)) / 1e9}")
# print(f"{tx_id} #{msg_id}: {data.hex()} {self.decode_packet(data)}, {payload.rssi} dB(?) RSSI, {payload.snr} dB(?) SNR {(time.clock_gettime_ns(0)) / 1e9}")
self.print_data()
def send_packet(self, target: int, data):
assert len(data) < 256
payload = []
payload.extend(target.to_bytes(2, "little"))
payload.extend(self.server_address.to_bytes(2, "little"))
# TODO: is this the best idea? Clock change would affect it badly
payload.extend(int(time.time()).to_bytes(4, "little"))
payload.append(len(data))
payload.extend(data)
hash_function = blake2s(key=self.server_secret_key.to_bytes(8, "little"), digest_size=8)
hash_function.update(bytearray(payload))
payload.extend(hash_function.digest())
#print(payload)
self.lora.send(payload, 255)
self.lora.set_mode_rx()
def print_data(self):
for device_id in self.devices:
device = self.devices[device_id]
print(f'Node {device_id} @ ID {device["last_message_id"]}:')
if "status" in device:
print(f'\t{device["status"]["battery"]:.3f} V {device["status"]["temperature"]:.1f} °C')
if "sensors" in device:
for sensor in device["sensors"]:
if sensor["value"] == math.nan:
print(f'\tCH {sensor["channel"]} on Pin {sensor["pin"]}: ERROR')
else:
print(f'\tCH {sensor["channel"]} on Pin {sensor["pin"]}: {sensor["value"]:.4f} {self.sensor_type_table[sensor["type"]]}')
print()
if __name__ == "__main__":
multinode = MultiNode()
while True:
multinode.loop()