jfehre / IoT-LoRa-Ultrasonic

Arduino Projekt for TTGO ESP32 with ultrasonic sensors: SKU (A02YYUW), AJ-SR04M and HC-SR04

IoT LoRa Ultrasonic

Introduction

The goal of this arduino project is to create an IoT Device which measures the distance and uploads data over The Things Network to the OpenSenseMap. Between measurements the microcontroller goes into deep sleep. The focus lies on an low power consumption solution, so the sensor is able to measure data over several months.
For measurement, this script supports two ways of communicating with an ultrasonic distance sensor:

• UART Serial: (tested with the waterproof ultrasonic sensor SKU (A02YYUW) from dfrobot.)
• Analog (Trig/Echo): (tested with the AJ-SR04M and HC-SR04 Sensors)

TTGO ESP32 LoRA: The first approach happened with an TTGO ESP32 LoRa board. However the power consumption of the board during deep sleep is too high (10mA). Furthermore the sensors always drained power (even during deep sleep), but this could be solved by powering the sensor with a GPIO Pin.
-> see subfolder TTGO-ESP32-Ultrasonic.

HelTec CubeCell: As a result of the high power consumption during deep sleep a Heltec CubeCell microcontroller is used, which should need 2µA during deep sleep.
-> see subfolder Heltec-CubeCell-Ultrasonic.

Getting Started

1. Backend Setup

Whatever microcontroller or ultrasonic sensor is used, the backend setup is the same.

1.1 The Things Network

1. If you aren't already registered, set up a The Things Network account
2. Create a new Application in TTN Applications Console
3. Create a new end device and set following parameters:
   • Frequencyplan -> depends on your location
   • LoRaWAN version -> This depends on the version set in the Arduino-LMIC library. Default is MAC V1.0.3
   • Other parameters can be generated
4. In your Application select Payload Formats and set it to Cayenne LPP
5. For the integration with OpenSenseMap, select Integrations in your Application and create a new Custom webhook
6. Choose a unique 'Webhook ID' and use JSON as the 'Webhook format'. The 'Base URL' should be https://ttn.opensensemap.org/v3. It is important to enable 'Uplink message'. The remaining fields can be left out (See here).

1.2 OpenSenseMap

1. If you aren't already registered, set up a OpenSenseMap account
2. In your Dashboard create a 'New senseBox'
3. Fill in the appropriate data like 'name', 'exposure type' and 'location'
4. Select 'Manual configuration' for your Hardware and 'Add sensor' with Phenomenon: distance, Unit: mm and Type: ultrasonic.
5. In Advanced choose 'TheThingsNetwork-TTN' and add Cayenne LPP (beta) as 'Decoding Profile'. Furthermore add your 'TTN Application-ID' and 'TTN Device-ID' from your TheThingsNetwork application.
6. In Decoding Options choose 'Cayenne LPP Phenomenon' as Illumination (to support floats with uint16) and if not already set, the 'Cayenne LPP Channel' to 1.

2. Configure Microcontroller

This step depends on the microcontroller you are using. Please refer to the corresponding readme files:

1. TTGO-ESP32
2. Heltec-CubeCell

Contribution

You are more than welcomed to contribute to this project by trying out other microcontroller or share your experience :)