I’m working on a university project to develop a soil moisture and temperature sensor that communicates through LoRa and Meshtastic. I want to create a functional and reliable system, but I need guidance on the following aspects:
Sensor Selection – What are the soil moisture and temperature sensors for long-term outdoor deployment? Analog to digital device and cables.
LoRa & Meshtastic Network Architecture – How should I structure the network to ensure reliable data transmission? Devices and microcontrollers.
Cabling & Power Supply – Recommendations for wiring, power sources (battery/solar), and waterproofing solutions.
Gateway – Best practices for sending data to a local server.
Hardware & Firmware – Any suggestions for microcontrollers, LoRa modules, or libraries to use?
I’d appreciate any insights, component recommendations, or examples of similar setups. If anyone has experience with such a system, I’d love to hear how you tackled challenges like power efficiency, data accuracy, and network reliability.
I am just letting you know that I have seen the following video on the core-electronics website; however, I couldn’t figure out the exact sensors and devices to make a functional device fro the above purpose.
I can definitely start to help you with a few things here!
This is going to largely depend on the environment you are deploying in. If you are only sending data from point a to point b, and the 2 devices are within range of each other (better yet have some level of line-of-sight), that’s all you really need. A large reason we are using Meshtastic is that it just works consistently and is reliable. I have sent thousands of messages without error (besides a silly mistake like one not being powered on). If it’s only 2 devices and there aren’t too many around, I would keep them on the default frequency, but create your own private channel.
I can’t comment much on batteries and solar (I have about 3 unfinished projects at home exploring this ), but just some power-related numbers for you, we found that the Pico consumes about 20 ma on idle (if you have 2 Picos then 2x that), and when it transmits data, the Lora hat uses about 60 ma of power, but it only transmits the message for about 1 second so it’s fairly negligible. An OLED screen will add another 10-ish ma on top of this.
A potential power management thing here is a power timer. It allows you to completely shut off all power to a device for a set amount of time (a few seconds to 2 hours), then your project boots up, does what it needs to do, then you can use the 2nd Pico to send a signal to switch off the power for another set amount of time.
Also in terms of enclosure, your temperature will need airflow, and some level of water proofing. Most weather stations use something called a Stevenson Screen. Not too difficult to 3d print.
We are about to release a video today of connecting the 2nd Pico to the internet and using MQTT to create a gateway to the internet or what ever you need!
Thanks for responding to my post and for your willingness to help.
I’ve watched many of your educational videos on the Core Electronics website and YouTube, they’ve been really helpful!
I’m a PhD student at the University of Adelaide, and part of my research focuses on soil sensors for farms and gardens. The goal is to capture soil data and transmit it to a local PC or app, creating a localised soil information system with minimal reliance on the internet.
I’d like to keep the development process simple and work in stages. The first stage will focus on soil sensors connected to a microcontroller and LoRa for connection, possibly in a mesoblastic network.
Would you be able to provide a list of components I need to purchase from Core-Electronics, including:
Soil sensors
Converter (analog to digital)
Cables
Microcontroller
Display
LoRa Node Module for Raspberry Pi Pico
I’d really appreciate your guidance. Thanks in advance for your help!
Please let me know if you require further information
If you’re looking to have the nodes reporting back to a central unit, you wouldn’t need a screen as it can be accessed via a web browser, but if you do want one.
We do alternatively stock the below board combo, it is extremely small and would have the added advantage of having on board Bluetooth and WiFi. Unlike the other LoRa module it does come with an FPC antenna so its range will be a little lower (this can be upgraded if needed).
Thanks for your time and for providing such comprehensive information.
I’ve placed an order for the items on the list. Once they arrive, I’ll follow Jaryd’s videos and hopefully assemble the sensors correctly. If I get stuck, I’ll reach out again in this post
), but just some power-related numbers for you, we found that the Pico consumes about 20 ma on idle (if you have 2 Picos then 2x that), and when it transmits data, the Lora hat uses about 60 ma of power, but it only transmits the message for about 1 second so it’s fairly negligible. An OLED screen will add another 10-ish ma on top of this.
