Battery-Powered Silo & Level Measurer: Pico LTE and Azure

The Sixfab Pico LTE is a special board for making Internet of Things (IoT) devices. It puts together two important things: the Raspberry Pi Pico W and the Quectel BG95-M3 modem. This mix makes it a really useful tool for trying and building IoT projects. The Sixfab Pico LTE has all the parts you need and many cool features. It lets you play with Pico W and LTE technologies, so you can learn and try new things.

In today's rapidly advancing world, smart technologies are transforming various industries, including agriculture and industrial storage management. The Silo & Level Meter project combines the versatility of the HC-SR04 Ultrasonic Distance Sensor, the power of the Raspberry Pi Pico microcontroller, and the convenience of cellular connectivity through the Pico LTE SDK. This project aims to develop a battery-powered, IoT-enabled Silo & Level Meter that measures the distance of storage materials and sends real-time data to the Azure IoT Hub platform. With this comprehensive guide, you'll learn the step-by-step process to create a cutting-edge solution for efficient and automated storage management

Components Needed

1. Sixfab Pico LTE

2. SparkFun Qwiic Ultrasonic Distance Sensor - HC-SR04

3. Waveshare UPS Module For Raspberry Pi Pico, Uninterruptible Power Supply

4. Micro USB cable and Jumper Wire

Official Documentation

Follow the details of steps 1, 2, and 3 in Sixfab's official documentation. There won't be too many details provided here.

Pico LTE Getting Started

Pico LTE SDK for MicroPython

1. Register Pico LTE board

Login to connect.sixfab.com, then click on Assets from the side menu. Next, click on the Register Asset button to input your device information and save it. To enable cellular communication for your Pico LTE, set the Asset status to 'active' and save the changes.

2. Install MicroPython

Install MicroPython firmware on the Raspberry Pi Pico of the Pico LTE board.

3. Install the Pico LTE SDK

Pico LTE SDK is an innovative framework that enables developers to integrate cellular communication capabilities into their embedded systems projects seamlessly.

4. Connect the HC-SR04 ultrasonic distance sensor module to Pico LTE

Connect the HC-SR04 sensor to the SPI pins of the Pico LTE as shown in the image.

5. Connect UPS Module for Raspberry Pi Pico

Firstly, to use the uninterrupible power supply (UPS) module with the Pico LTE, you need to solder a stacking header onto it. After soldering the header, you can easily stack the UPS module on top of it. The battery used is a rechargeable AA Li-ion 3.7V 900mAh Lithium-Ion Battery.

6. Install HC-SR04 Sensor driver on Pico LTE in Micropython

The 'micropython-hcsr04' driver was used for the HC-SR04 sensor in Micropython.This library code can control an ultrasonic sensor with a Pico.Its usage is quite simple; for detailed information, visit the GitHub page. To install it, all you need to do is upload the 'hcsr04.py' file to the Pico LTE.

7. Azure IoT Hub Integration

Integrating Pico LTE with Azure IoT Hub is explained step-by-step in Sixfab's official documentation on the 'Azure IoT Hub Connection' page. By following the instructions carefully, you will be able to send data to the Azure IoT platform using MQTT.

8. Send the data to Azure IoT

The provided code, when executed in Thonny IDE, will measure the vacant space in the grain silo in centimeters and transmit this data to the device dashboard created on Azure IoT Hub.

If desired, after subtracting the measured distance from the total length of the silo, the amount of space occupied by the grain can be calculated, taking into account the container's volume. Thereby, as the quantity of grains varies, their weight can be calculated and this data can be directly sent to Azure IoT.

NoteIf the results from the ultrasonic module show a value close to 0 (Distance: -0.017 cm ), the wave sent could not be received. This could be due to a timeout of the time_pulse_us() function. For accurate measurement, the obstacle should have a flat surface.

By following this step-by-step guide, we have successfully created a Smart Silo & Level Meter using the Raspberry Pi Pico with cellular connectivity via the Pico LTE card. With Azure IoT integration, we can remotely monitor the silo's contents, enabling efficient storage management and ensuring timely actions based on the level data. This project serves as a versatile foundation for various IoT applications and provides valuable insights into using cellular connectivity and Azure for data management in IoT projects.