Integration Process
In this page, I will describe the integration process to assemble all the parts, mechanical and electrical to work together as one system to achieve the functions that I intended for the tea maker machine.
The function and system integration schematic can be seen below:
But I want to achive this system integration by doing small steps which is to combine few of the input/output devices first before integrating them all together.
Combining the 2 servo motors to work together
I first attempt to make the 2 servo motors to work together.
To do this, I used the built-in code in arduino ide and add the second servo as myservo 2.
to download the arduino sketch code for this 2 servo motors
It can be seen in the video that the alligator clip is moving up and down with the arm movement (both of them are connected through the nylon string and driven by the servo motor on the base. Besides that the pinion is rotating clock wise and counter clock wise while moving the rack up and down.
Combining Temperature Sensor and I2C LCD
I also attempt to combine the DS18B20 with the I2C LCD panel to display the reading of the temperature on the LCD panel.
The details of the DS18B20 temperature sensor can be seen in exercise 9, Input Devices page.
While the details of the I2C LCD panel can be seen in exercise 11, Output Devices page.
I use the below arduino sketch code.
In order for this code to work, several libraries such as "one wire", "dallas temperature" and liquidcrystal_I2C" must be downloaded. How to do this can be seen in exercise 9, Input Devices page and exercise 11, Output Devices page.
to download the arduino sketch code for this DS18B20 + I2C LCD
In the video above, I started with the temperature probe measuring ambient temperature at around 21 to 22 degree celcius. After that I poured hot water around 68 degree celcius and let the temperature sensor measure the water temperature. It can be seen in the video that the temperature rises rapidly at the beginning and start to rise slowly around 60 degree celcius.
Combining all input and output devices
After comfortable integrating some of the input/output devices, I attempted to integrate all of them.
But first, I need to visualize the state of the mechanical parts at each steps.
Below is the code that I used for testing.
The new syntax in this program is the "if" function, where only when the temperature is equal or below 90 degree celsius and higher than 70 degree celsius then the tea bag will be lowered to the cup and remain there for 30 seconds as the infusion tea time.
After 30 seconds the tea bag will be lift up from the cup and finally the temperature probe will be lift up from the cup.
to download the arduino sketch code for this integration test
It can be seen in the video that the program worked well where the temperature sensor measured the temperature of the water to be 85 degree Celsius and then the tea bag is lowered to the cup and remained there for 30 seconds.
After 30 seconds, the tea bag was lifted up from the cup and then the temperature probe was lifted up from the cup too.
I will improve on the programming to include some small shaking of the tea bag during the infusion to make the diffusion more distributed in the water.