Team UVU by Natalie Hua, Fan Feng, Chengyao Liu, and Dylan Brown presents an instructable that demonstrates how to create an Ultra Violet (UV) Radiation sensing band, which is connected to an e-ink screen to display images at certain UV exposure levels. This process applies to the independent use of UV sensors and E-ink screens.
Step 1: Material Breakdown
The Process is completed in two simple stages. This consists of creating a DIY silicone wristband to house all technical components and programing the UV Sensor & E-ink display.
Step 2: Stage 1 - UV Sensor & E-Paper Display Technical Package
UV Sensor Contents:
- Arduino Uno R3
- Grove UV Sensor
- Grove – 4 pin male jumper to Grove 4 pin conversion cable
- USB 2.0 Cable – A-Male to B-Female
E-Paper Display Contents:
- Waveshare E – paper Shield
- Waveshare E – paper 1.54-inch display
Step 3: Stage 1 - Arduino Set-up
- Download the Arduino IDE application from the link listed below (Both Window or Mac version is available) and install the program
- Connect the Grove UV sensor to the Arduino Uno R3 board using 1 Grove 4 pin male jumper to Grove 4 pin conversion cable (connect the male pins based on the provided image above)
- Using the USB 2.0 Cable Connect it from the Arduino Uno R3 Circuit Board to your laptop and open the Arduino Application so it syncs up with the circuit board
Step 4: Stage 1 - E-ink Display Set-up
- Connect the UV Sensor to the Waveshare E-Paper Shield by following the steps provided in the above visual.
- To connect the Waveshare E-paper display, insert the orange tab into the E-paper shield slot
Step 5: Stage1 - Coding
- Using a QR scanner to scan the code in the image above or clicking on the provided link below provides both the UV Sensor and E-paper Display code combined.
- Once downloaded, the code in the file needs to be copy and pasted directly into the Arduino IDE application.
- After pasting the code, click on the upload button to input data directly into the motherboard which will control the sensor and display.
Step 6: Stage 1 - Image Input
- The image names coded from Step 2 file’s can be downloaded in the provided link
- Once downloaded, relocate the folder to onto your laptop’s desktop and click the upload button to re-input all coding into the Arduino Uno R3, to ensure there are no missing files.
Step 7: Stage 1 - Coding Finalised
- Now that all codes have been inputted into both the sensor and display, the Arduino Uno R3 can be disconnected from the laptop
- A battery can now be connected to the Arduino Uno R3 so that it is able to run independently This is now ready to be slotted into the DIY bracelet
Step 8: Stage 2 - DIY Silicone Bracelet
Step 9: Stage 2 - 3D Printing
- Download the 3D printing STL file directly from the link provided
- Once downloaded prepare the STL file fitted to your 3D printer’s bed size, ensure support is on and rafting is turned off.
- Prepare your 3D printer’s PLA+ filament and printing bed temperature to 205-225 degrees.
Step 10: Stage 2 - 3D Printed Mould Preparation
- Once both print files are completed, remove all support from the 3D print and sand down the mould surface for a smoother surface finish
- Start with 200 grit sandpaper and once the 3D printed grooves have been sanded enough, use 600 grit sandpaper until mould is smooth.
- Rinse mould to remove all sanding residue and dry mould with paper towel or cloth
Step 11: Stage 2 - Silicone Preparation
- Please Note: Before pouring the silicone, it has a cure time of 8 minutes at room temperature and it should not be removed from the mould until 30 minutes has passed. The more silicone pigment is added to the mix, the colour becomes darker and more opaque
- Prepare a disposable plastic cup, and ensure both Bottle A and Bottle B are poured to a 1:1 ratio, 20ml of silicone A and Silicone B is enough for the first batch
- Add the amount of silicone pigment to your choosing, a small amount of pigment goes a long way (colours are also optional to creator’s choice)
Step 12: Stage 2 - Bracelet Creation
- Once all components are added, mix silicone thoroughly for less than 2 minutes and pour it directly into the mould, so that it fills up to 1mm of the mould
- After 8 minutes, place the piece of spring steel in the centre of the mould
- Create a second silicone mix consisting of 25ml of Silicone A and 25ml of Silicone B (with pigment)
- Pour this over the spring steel and fill the mould
- After pouring the silicone into the mould, carefully tap the mould against the table until all air bubbles are removed
Step 13: Stage 2 - Mould Removal
- Using a Stanley knife or exacto blade, carefully cut around the edges of the silicone to help create an easy release
- Slowly lift one edge of the mould and lift upwards until bracelet is completely removed
Step 14: Stage 2 - Bracelet Completion
Now neatly slot all the hardware into the bracelet and it is now ready for action