Coffee Grinder based on Seeed Studio XIAO ESP32C3

A coffee grinder is great for grinding coffee, but what if you wanted to produce a certain amount of ground coffee automatically? The Eureka Mignon Libra device is capable of such an operation, but creator Tech Dregs (TD) had only a Eureka Mignon Crono that lacks – or lacked – this functionality. Now, with the addition of a Seeed Studio XIAO ESP32C3 board and a load cell, coffee grinding is fully automated and features a smartphone Bluetooth interface.

Seeed Hardware: Seeed Studio XIAO ESP32C3

Software: Arduino IDE

Industry: Smart Home

Solution Deployment: United States


The Eureka Mignon Crono is a popular among coffee enthusiasts, but it lacks the ability to produce a specific amount of ground coffee automatically. This limitation led Dregs (TD) to develop a solution using the Seeed Studio XIAO ESP32C3 board and a , which allows for fully automated coffee grinding. With this new device, users can specify the exact amount of coffee they want, and the grinder grinds the beans to produce the desired amount automatically. Additionally, the device features a smartphone Bluetooth interface, allowing users to control the device remotely from their smartphones. This innovation has the potential to greatly simplify and improve the consistency of each cup of coffee. By automating the , users can focus on other aspects of , such as water temperature and , to produce the perfect cup of coffee every time.

The Challenge

There may be several challenges when working on this project. Firstly, integrating the Seeed Studio XIAO ESP32C3 board and load cell into the Eureka Mignon Crono coffee grinder can be a technically challenging process, requiring careful consideration of the device’s mechanics and electrical systems. Additionally, ensuring the accuracy and reliability of the load cell can be challenging, as it must be able to accurately measure the weight of the ground coffee in real-time. Furthermore, integrating the smartphone Bluetooth interface can require expertise in software development and wireless communication protocols.

Another potential challenge is ensuring the compatibility of the device with different types and blends of coffee beans. Different types of beans may require different grinding times and methods, which may need to be adjusted to ensure optimal performance. Additionally, the device may require periodic calibration to maintain accuracy and consistency over time.

Finally, there may be challenges in marketing and selling the device, as it may be difficult to compete with other automated coffee grinders on the market. The device may require a unique selling proposition or marketing strategy to stand out from the competition.

Another challenge that TD faced in the early stages of the project was the integration of a cheap scale purchased from Amazon for its load cell. TD found that the internal integrated circuit of the scale was not conducive to epoxy encapsulation. This presented a challenge for the integration of the scale with the rest of the coffee grinder system, as it required a custom enclosure to protect the scale’s circuitry from moisture and other environmental factors. This highlights the importance of careful component selection and testing in hardware projects, as even seemingly small components can have a significant impact on the overall system design and functionality.

Overall, while there may be some challenges involved in developing and marketing this device, the potential benefits of fully automated coffee grinding and the convenience of a smartphone interface may make it a compelling product for coffee enthusiasts and professionals alike.

The Solution

To address the challenge of integrating the cheap scale with the rest of the coffee grinder system, there are several potential solutions that TD could consider.

One option is to replace the cheap scale with a higher-quality scale that is designed for use in harsh environments and can be more easily encapsulated or protected. This would require additional cost and testing to ensure that the new scale is compatible with the rest of the system, but may provide a more reliable and durable solution in the long term.

Another option is to modify the existing scale to make it more suitable for integration with the coffee grinder system. This could involve encapsulating the circuitry with a different material or designing a custom enclosure to protect the scale from moisture and other environmental factors. This would require additional testing and development to ensure that the modified scale still functions accurately and reliably.

Finally, TD could consider redesigning the coffee grinder system to use a different type of load cell that is more easily integrable with the system. This could involve selecting a load cell with a different form factor or designing a custom mounting solution to ensure compatibility.

The decision to switch to an HX711 load cell from SparkFun was a smart move by TD, as it allowed for a more convenient and reliable integration with the rest of the coffee grinder system. The HX711 load cell is designed specifically for use in weight sensing applications and features a built-in amplifier that can provide a more accurate and stable signal. Additionally, the HX711 load cell is easier to interface with the XIAO ESP32C3 board, as it uses a simple two-wire serial interface that is compatible with a wide range of microcontrollers.

Overall, while the challenges presented by the cheap scale may require additional testing and development, there are potential solutions available that can help to overcome these challenges and ensure the success of the project.

The Results

We successfully created an automated coffee grinder device that features an onboard OLED screen and a created using MIT’s App Inventor program as the main user interface. The device is capable of dispensing ground coffee accurately and consistently, allowing users to specify the exact amount of coffee they want. The device uses a to measure the weight of the ground coffee in real-time, which ensures accurate and reliable coffee grinding. Although there were a few small issues that could be improved upon, overall the device performs well and represents a significant achievement in automated coffee grinding. The project demonstrates the potential of integrating hardware and software to create to real-world problems and serves as a great starting point for others interested in developing similar projects.

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April 2023