Improving Quality of Life: A Tea Pouring Solution for Anton
Understanding the Need
Living with a disability poses challenges beyond the physical realm, affecting various aspects of life, from social interactions to economic opportunities. Individuals with disabilities often face difficulties in performing seemingly simple tasks that many take for granted. Meet Anton, a cool programmer from Ukraine with cerebral palsy. Heβs all about that super-strong Chinese tea, which powers his brain at 200%. But hereβs the kicker: pouring tea with cerebral palsy?
While many may view the inability to pour tea independently as a trivial matter, for Anton, it represents a significant challenge impacting his sense of autonomy. In this series of articles, Anton and I develop an end-to-end solution to enhance his quality of life using affordable and accessible technology. The aim is to share this experience, so that other people can replicate similar projects, improving autonomy where it is needed the most.
Designing the Solution
To address Antonβs need for a tea-pouring mechanism, we decided to create a simple yet effective device. The primary components include a container for hot tea, a cup, and a pump to transport the tea between them. Crucially, the system must be controllable via an API accessible over the local Wi-Fi network, allowing Anton to trigger the pouring process conveniently.
Challenges and Solutions
- Voltage Mismatch: Microcontrollers operate at 3.3β5V, while the pump requires 12V. To manage this, a transistor or relay is employed to switch the pump on and off. We will use the motor shield to help us in this matter.
- Enclosure: To ensure safety and neatness, all components are enclosed in a suitable casing, protecting them from external elements and potential spillage. This is a separate topic that Anton and I will develop later, as it is highly dependent on the design decisions made here.
- Food Safety: Given the application involves hot liquids, all materials used, including tubing and the pump, must be food safe.
Shopping List
1. Microcontroller Arduino Uno Rev 4 Wi-Fi: The Arduino Uno Rev 4 Wi-Fi was chosen for its robust ecosystem, extensive documentation, and active community support. It integrates Wi-Fi capabilities, enabling remote control through the API.
2. Motor shield Rev 3: Its compatibility with the Arduino Motor shield Rev 3 simplifies motor control tasks.
3. Pump: 12 Volt Food safe Aquarium/Tea machine Pump: A compact and food safe pump capable of handling hot liquids. The 12V voltage requirement aligns with the power source picked for the project.
4. Power Supply: 12 Volt/2A Barrel Plug Power Brick: To power both the Arduino Uno and the pump, a 12V/2A power brick with a barrel plug compatible with the Arduinoβs barrel jack is selected.
5. Tubing: 6 mm/8 mm Food safe Silicon Tubing: Food safe silicone tubing ensures the safe transfer of hot liquids from the container to the cup.
Hardware Choices
To materialize our solution, we totaled 95,57 euros when sourcing all components from Amazon in Germany. We point out that this not necessarily cheap, and we aim to improve this in the following iterations of this project.
- The Arduino Uno Rev 4 Wi-Fi and Arduino Motor shield Rev 3 were selected for their reliability, rich features, and community support. This definitely comes at a price though, as these 2 components make up for more than half of the budget at 58,51 euros.
- To bridge the voltage gap, a 12V food safe pump and compatible power supply were included, along with a Motor shield that can handle the 12 Volt current via a switching IC, supporting both relay and PWM control. Whether we need to control the pumping speed and therefore, whether we need PWM control, is arguable at this stage of the project.
- The liquid is hot and meant for consumption, meaning that we accounted for this in both the tubing and the pump. Both are rated as food safe. The pump has an operational temperature window of up to 80 degrees Celsius, which is not ideal, but good enough for now. The tubing is rated for up to 180 degrees Celsius, which is ample.
Next Steps
In the next article, we will delve into wiring and programming of the components. The article after that will develop the concerns for an enclosure. Lastly, we will evaluate the first iteration of the project and point out improvements.
Resources:
- GitHub Repository that tracks the entire project: https://github.com/psmgeelen/projecttea
