Blog from October, 2022

LoRa PCB sender checkout
James Hughes posted on Oct 26, 2022

PCB arrived today.

Initial Setup

  1. Soldered JP1,2,3 (debug LED, power , and charge indicator)

  2. Set to ESP32 DevKit

  3. Blink is working and printing to serial console on programmer UART

Initial TODO

  • Hello World!
  • Evaluate charger circuit
  • Add compiler directive for non-Heltec software build
  • ADC review for VBAT
  • ADC review for VSOLAR
  • Digital CHGST pin read
  • Rain gauge interrupt routine back online
  • I2C evaluation with BME280
  • Weather direction evaluation
  • Wind speed evaluation
  • New LoRa radio install for 915MHz
  • Calibrate ADC for VBAT
  • Calibrate ADC for VSOLAR
  • Verify I2C power switch
  • Verify LoRa power switch

Evaluation Notes

Charger Circuit

LED is on when charging

Mounting alternate pinout LoRa radio

I’ll be using Caption tape to insulate the pads from the module electrical points. The good news is that the GND pads and antenna match, so those will be soldered directly.

I2C operating with BME280

Had to add intentional delay for wind speed data collection as there is no WiFi connect negotiations to rely on.

Getting my LoRa radio to connect to the PCB will be a total hack job. Bringing it to work tomorrow to use the precision soldering iron.

Prepped LoRa radio for modifications. I’m using high temperature Kapton tape to insulate pads that I’m intending on soldering jumper wires to.

Not as elegant as planned, but LoRa radio is verified. A total freaking hack job!

Sensor → LoRa → MQTT → Home Assistant

  • Data makes it to Home Assistant
  • Rainfall hourly accumulation
  • Rainfall 24h accumulation
  • Wire up DS 1-wire sensor
  • Correct BME temperature in MQTT or HA (unit of measure is wrong)

Home Assistant - Weather sensor data

Home Assistant - Hardware sensor/health data

Mostly morning towards formal beta testing release on sender and receiver software at this point in time.

Initial program development notes
James Hughes posted on Oct 02, 2022

I’m creating a seperate blog entry for general program development notes

  • Weather station now reads BME280 (good test sensor choice with 3 readout values)

    • Relative humidity and barometric pressure are placed in the sensor structure

    • Temperature is placed in the hardware data structure to represent case temperature

  • ESP32 core temp is also read

I now have values to play with to get the receiver of the data to convert values to MQTT.

As software is developed, I’m going to maintain the mindset that zero calibration for ADC values, wind direction, etc… need to happen at the station. I want to get to the point where station is flashed and left alone as much as possible. Calibration will happen at the receiver (much more accessible)

Receiver now forwards hardware sensor data to broker.

  • Completed initial receive of environment data structure and forward values to MQTT broker. Still need to bring rain and wind measurement online.

  • Starting to envision an elegant way to periodically calibrate the RTC.

  • Started a battery life test on the devKit with a 500mAh battery and 3 minute wave cycles. I won’t be able to do much coding for the next couple of days and wanted to understand how it is performing.

LoRa data is seeming to be quite stable with reporting. Red data sets are hardware parameters and yellow are weather sensor data.