Project Development

8 June

Week18 Project Development

Project Progress

- Research on Tea

Up till now I only have less than two weeks left until the date I should present my final project. So far I have done research on different tea types and have made a thorough table controlling each temperature, time to fuse, number of fusions, tea-water ratio, and tea pot material for 6 selected types of tea in China.

- Research on Overall Design

I've done a considerable amount of research on various automated tea brewer in the market and materials that's heat-resistant for each part of the machine - the box, the heating platform, the container, the tape. And I've got the materials that are safe to use under the high temperature.

I have given up the control for leaf-water ratio and the material due to time constraint. For this prototype, I'll just control the temperature and time.

- Technical Preparation from Previous Weeks

For the automated tea brewer project, I could adapt what I've done in previous week and put them together. The thermistor from week to do an input device, the servo and the PWM controlled ceramic heating pad from the week of output device, and the bluetooth communication module that connects my mobile to my microcontroller from the week of network.

* box design: the bottom part of week 5

* thermistor: week 11

* servo: the top part of week 13

* heating pad: the bottom part of week 13

* bluetooth connection: week 15

* app development: week 16

Remaining Problems

There are still problems to be solved:

1. Power supply to the heating pad. In the week I did the output device, I connect the ceramic heating pad to the MCU directly and it heated up. But in this week I need to control how high this temperature goes and the highest could reach nearly 80-100 degress. Therefore the power supply remains a problem. Under the advice of two of my colleagues, Vincent and Barry, in Fablab Shanghai, I decided to use an external power supply. When I found one, it turned out to be an extremely bulky stuff and all electronic components were exposed therefore it's neither aesthetically beauutiful nor safe for tea brewers to use. So I decided to make a box that would wrap all of them up.

2. For the part that separates tea and leaves, I gave up my idea of using some sort of moveable platforms and chose to use the servo to lift the tea bag considering the time limitation. Problems remained in how much weight could the servo lift as the tea bag would get a lot heavier when it's thoroughly soaked in water. Apart from that, the angle that the servo rotates should be tested in order to lift the tea bag without dripping extra water out of the conntainer.