At Zimmer and Peacock, we are always looking to adapt and provide innovative solutions for our clients and collaborators. ZP were approached to design a solution for testing the power requirements of a Nitrate Rod when connected to a solar panel whilst simultaneously accessing the data over a short-range wireless network. To develop this solution, ESP32 modules have been implemented. An ESP32 development module is a low power microcontroller, similar to Arduino and Raspberry-Pi boards, but with built in wireless capabilities such as Wi-Fi and Bluetooth.
Two of these modules will be used to wirelessly acquire and display the information from the Nitrate Rod, one acting as a slave and the other as a master. The Nitrate PCB will pass the sensor readings to the slave ESP32 module through a serial connection and those readings will then be transmitted to the master ESP32 module. The means of transmission is through a protocol called ESPnow, which operates on Wi-Fi frequencies but boasts a theoretical range of up to 200m. Once the data is received at the master device, it will use its built in Wi-Fi connectivity to connect to the local Wi-Fi network and host a web server. This webserver can be accessed by any user device connected to the same local Wi-Fi, such as a PC, laptop, phone or tablet. This webpage will display the data from the Nitrate Rod including the raw voltage reading and the battery voltage. Both sets of data will also be visible in graphical form to show trends over time. These sets of data will allow the user to evaluate the battery voltage and capabilities of the solar panel which is powering the system.
This has been ZP’s first experience using ESP modules, but it is highly unlikely that it will be the last! ESP32 modules provide a wealth of opportunities for future growth on AgTech projects. The configuration described above uses a single module in the field transmitting data in one direction to a master, however, there are many other configurations which can allow for expansive capabilities. Many modules scattered in the field would be capable of transmitting data to the single master module and accessing the data through a similar web viewer. Two-way communication is also possible, meaning requests could be sent for information on-demand. By fully harnessing the potential of the ESP32 modules, the possibilities are almost endless!