Retrieving INA219 data (Current and Voltage)

1

Looking at the INA219Sensor.cpp source code I see:

bool INA219Sensor::getMetrics(meshtastic_Telemetry *measurement)
{
measurement->variant.environment_metrics.voltage = ina219.getBusVoltage_V();
measurement->variant.environment_metrics.current = ina219.getCurrent_mA();
return true;
}

Which tells me that the current and voltage of the INA219 is in the ENVIRONMENTAL_MEASUREMENT_APP packet coming from the node.

Looking at the environmental_measurement_pb2.py

_descriptor.FieldDescriptor(
  name='voltage', full_name='EnvironmentalMeasurement.voltage', index=4,
  number=5, type=1, cpp_type=6, label=1,
  has_default_value=False, default_value=float(0),
  message_type=None, enum_type=None, containing_type=None,
  is_extension=False, extension_scope=None,
  serialized_options=None, file=DESCRIPTOR,  create_key=_descriptor._internal_create_key),
_descriptor.FieldDescriptor(
  name='current', full_name='EnvironmentalMeasurement.current', index=5,
  number=6, type=1, cpp_type=6, label=1,
  has_default_value=False, default_value=float(0),
  message_type=None, enum_type=None, containing_type=None,
  is_extension=False, extension_scope=None,
  serialized_options=None, file=DESCRIPTOR,  create_key=_descriptor._internal_create_key),

I see where the voltage and current are listed. However when i receive a packet from the node that has the INA219 module on it, I am getting 0 VDC and 0 Amps, which i know is not true.

I am showing on the node that the
Sensor Options: Enabled
Show on device screen: Enabled
Display Fahrenheit: Enabled

I am seeing the current and voltage correctly on the OLED, but it is not in the data stream. As a matter of fact, ALL of the environmental variables from the telemetry stream are showing a value of 0.0.

2

Run the serial monitor when the device boots and look for the sensor detection

3

If it’s showing correctly on the screen, then the sensor should be detected already.

But, as I mentioned before and as stated in its README, meshtastic-mqtt only works with firmware 1.2, not with 2.0. In 2.0, there is no environmental_measurment_pb2.py anymore, it’s in telemetry_pb2.py. New generated files are here: python/meshtastic at master · meshtastic/python · GitHub

However, if you enable JSON, exactly what you’re trying to do with Python is already done in the firmware, but then it is published to the msh/2/json/# MQTT topic. Right now you probably set it to msh/2/c/# in meshtastic-mqtt, which then converts the protobufs to something readable, but if you look at the data in msh/2/json/#, it will be in plaintext already. Maybe check with the CLI (meshtastic - -info) if mqtt.json_enabled is really set to true.

Another benefit of letting the firmware do this is that if in a newer version any of these definitions change, you don’t have to update your Python files.

4

Setting the to msh/2/json/# when I send a text I get:

Connected to MQTT Broker!
<paho.mqtt.client.Client object at 0xb6569dc0>
None
<paho.mqtt.client.MQTTMessage object at 0xb60d08b0>

So how do I decode this? I have confirmed that json is “ON” on the node that I have the WiFi and such activated.

5

Your’re now printing an object. Probably you need to print msg.payload or something equivalent.

Or you need str(msg.payload.decode("utf-8"))), I’m not sure, never used this in Python.

6

Let me skin this cat another way. i am have a Mosquitto running in the background.

All i want to do is get all the traffic that comes across that node for the simple matter of being able to monitor the V and I of a remote node.

- and appologies…

I know ZERO about json, so anything you could point me to that would help me get this off the ground would be greatly appreciated!

7

Please slow down, I’m only trying to help, and I think you’re almost there.

JSON is just a human-readible format. Probably in def on_message in meshtastic-mqtt you can just directly use print(str(msg.payload.decode())).

I’ve only used MQTT with Home Assistant and openHAB, which can directly display any JSON data.

8

I would also recommend http://mqtt-explorer.com/. Then you’ll probably see directly how the data looks like.

10

Will bookmark that page…My goodness that was a test of human endurance…I’ve been working this for hours and hours…

thanks again…

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