Creation of timestamp switch using UV sensor

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Warp_Wanderer
 
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Creation of timestamp switch using UV sensor

Post by Warp_Wanderer »

Hello Adafruit Community,

I'm looking to create a device that will record a timestamp if the voltage of my UV sensor falls below a certain threshold. Due to the fact that this sensor will be in use 24/7 for over a week at a time, I'm looking for an option that wouldn't tie up a laptop or desktop computer. Looking over the DIY projects, it looks like there are some with similarities, but being new to electronics creation I could use some help identifying which products I would need (ie. data logger, switches, raspberry pi, etc) and any resources I can use to assist in determining the best assembly configuration and methods.

Sincerely,
Joseph Cunningham
PhD Candidate
Virginia Tech Aerospace Engineering
Lunar Composites Research

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adafruit_support_mike
 
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Re: Creation of timestamp switch using UV sensor

Post by adafruit_support_mike »

That would be a good application for a datalogger. I'd suggest a Feather M0 with an SD/RTC daughterboard:

https://www.adafruit.com/product/2772
https://www.adafruit.com/product/2922

The microcontroller has a 12-bit ADC, so it can track 3.3V signals with a resolution less than 1mV. The RTC will let you generate reliable timestamps, and the SD card will let you write data to a text file.

The Feather runs on 11mA. The RTC uses less than 1mA, and while most SD cards require about 50mA while writing data to storage, you probably won't be doing that constantly. Overall, I'd guess 20mA is a generous estimate for the average operating current.

The system can run indefinitely from a DC wall adapter. If you want to run it on a battery, figure about 2 days of runtime for every 1000mAh of battery storage capacity. To run it for more than a week, I'd suggest a 6600mAh LiPo battery:

https://www.adafruit.com/product/353

That should be good for a little less than two weeks.

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Warp_Wanderer
 
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Re: Creation of timestamp switch using UV sensor

Post by Warp_Wanderer »

Awesome, this is some great information. I'll do a little more research on the products you suggested and see if I can come up with a good system.

Thanks a bunch!

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Warp_Wanderer
 
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Re: Creation of timestamp switch using UV sensor

Post by Warp_Wanderer »

Hi Mike,

Wanted to confirm compatability between the products you mentioned and the GUVA Analog UV Light Sensor Breakout - GUVA-S12SD, which I plan to apply for my project. Will I need an amplifier or will directly hooking the sensor to the controller be sufficient?

In addition, I'm planning to use the Thermocouple Type-K Glass Braid Insulated (ID: 270) paired with the Thermocouple Amplifier MAX31855 breakout board (ID: 269) to take temperature readings, and would like to be able to track those readings and perhaps make a temperature floor time stamp as well.

Would I be able to integrated those sensors easily with the Feather M0 and SD/RTC with the previously noted components or would you suggest additional hardware?

Thanks again for answering my newbie questions!

Sincerely,
Warp_Wanderer

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Re: Creation of timestamp switch using UV sensor

Post by adafruit_support_mike »

Warp_Wanderer wrote: Tue Sep 13, 2022 4:23 pm Wanted to confirm compatability between the products you mentioned and the GUVA Analog UV Light Sensor Breakout - GUVA-S12SD, which I plan to apply for my project. Will I need an amplifier or will directly hooking the sensor to the controller be sufficient?
The GUVA-S12SD's output is an analog voltage, which the Feather can read with one of its analog input pins.

The GUVA-S12SD breakout has a built-in amplifier, and its output voltage is 4.3V per microamp of diode current.
Warp_Wanderer wrote: Tue Sep 13, 2022 4:23 pm Would I be able to integrated those sensors easily with the Feather M0 and SD/RTC with the previously noted components
Yeah, those will work with the rest of the parts you've chosen. The MAX31855 communicates with the microcontroller using a digital protocol called SPI. That's independent of the analog connection for the GUVA-S12SD.

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Re: Creation of timestamp switch using UV sensor

Post by Warp_Wanderer »

Awesome, thank you for the help!

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