Thermal fishing bob

This variation on the [thermal flashlight](/tool/thermal-camera) uses a cheaper **thermistor** instead of a non-contact IR thermometer ($20), but can only detect the temperature of things the sensor is literally **touching**. ## Questions [questions:thermal-fishing-bob] ## Activities [activities:thermal-fishing-bob] **** The circuit looks like this: Read here for build instructions by Sophia (RISD), using a thermocouple taken from a cheap medical digital thermometer: ![in-bottle]( Here is one, assembled: ### Concept The idea is to put this in a waterproof container with the the thermistor poking through the outside (but not letting water in) and to "cast" this into a waterway while taking a long-exposure photograph. This will create a "light painting" where the colors describe the temperature of the water at that location. Eymund Diegel has been doing some good sketches of this, focusing on a version where you drag the package around on the bottom of the canal, but the light is on the surface of the water (this will allow mapping of bottom temperatures, but will require more waterproofing). ![eymund-sketch]( **** (The following was copied from [the thermal photography page](/wiki/thermal-photography) and should probably be [posted as an activity](/post?tags=activity:thermal-fishing-bob&title=Build a DIY "thermal fishing bob"). The thermal fishing bob project develops a DIY technology to visualize changes in water temperature, which can [indicate water pollution via industrial sources]( or [sewage]( The fishing bob is designed simply enough that anyone can build it and its components can be easily obtained from Home Depot and Radio Shack. ### Project Goals: To produce a cheaply made, easy to use piece of technology to track temperature changes in water. And to produce a product that can be easily altered to suit many innovative needs. ### Research URL’s: First iteration of the Thermal Fishing Bob developed in Sara Wylie’s class at RISD: Second iteration of the Thermal Fishing Bob developed at 2014 Barnraising: First long exposure pictures with the fishing bob: [First Field test of the Fishing Bob]( [Research Notes on development workshops MIT]( [Barnraising]( [Northeastern University]( [Research notes on towing the tool]( [Next steps on developing the tool]( ### Building Your Own #### How To Guide ThermalBobHowTo.pdf The fishing bob’s tech is sealed within a waterproofed translucent container, a Koolaid mix container will do, with only the thermistor poking out the bottom (sealed around the edges with hot glue). The fishing bob is then wrapped in foam so that it floats, attached to a reel so it can be pulled, and dropped in the water. The thermistor reads changes in temperature and the LED within the fishing bob causes the fishing bob to change color in accordance with the temperature. The readings are recorded on the Arduino inside, which can then be read once it is plugged into a computer. While the fishing bob is being dragged across the water long exposure photos are being taken to create a “light painting” of the temperature gradient. One neat way to make these long exposure images is to use [glowdoodle]( from MIT. ### Materials * translucent plastic containers that can be easily sealed for waterproofing such as a takeout soup container or Koolaid mix container * 9 wires * [thermistor]( * [breadboard]( * [Arduino Uno]( * [3 Color LED]( * 9V batteries and holder * [2 100 Ohm resistors]( * [1 180 Ohm resistor]( * [1 10k resistor]( * hot glue gun * packing tape * wire strippers * scissors * small flathead screwdriver * foam * fishing/kite reel * [Arduino to USB cord]( * computer ### Thermal Fishing Bob Arduino Sketch ### Next Steps: I am currently working with Sara Wylie on a project to make the thermal fishing bob towable behind a kayak. In previous testing the fishing bobs tended to submerge and become water damaged so we are working on a prototype that would be set into a floatation device. One concept is to wrap two fishing bobs in foam and set them into the legholes of a child’s floatie, duct taping them into place. The first test was successful, the fishing bobs stayed in place above the water and there was no noticeable water damage. A second idea is to attach three fishing bobs to a foam sled/boogie board with thermistors of differing lengths to take a 3D image of the thermal gradient. This idea has yet to be tested. A third idea is to utilize ideas from the coqui to transform the thermal fishing bob into a conductivity fishing bob. This idea is still in the brainstorming stage, but we will be building a prototype soon. ### Images [![Untitled.png](]( Thermal plume along the Charles River [![Screen_Shot_2015-05-05_at_8.32.34_AM.png](]( Fishing bob made at MIT workshop from a soda cup [![Screen_Shot_2015-05-22_at_7.20.43_PM.png](]( Thermal fishing bob circuit [![Untitled3.png](]( Fishing bobs ready to go [![Screen_Shot_2015-05-12_at_5.59.31_PM.png](]( Fishing bob being lowered into the river [![Screen_Shot_2015-05-12_at_6.00.36_PM.png](]( [![Screen_Shot_2015-05-04_at_4.44.30_PM.png](]( First prototype of towable fishing bob **** ### Arduino code ### Updated Arduino code from 2013 Barnraising ...

Author Comment Last activity Moderation
eustatic "definitely include how these photos were taken. Cool! " | Read more » almost 9 years ago
karenv "Wow! Interesting, amazing, and incredibly helpful! " | Read more » almost 9 years ago
mathew "I love the in-depth historical storytelling. awesome research and thanks for showing others how to follow your process. " | Read more » almost 9 years ago
gpenzo "Very interesting concept. Wondering if it not easier to just use a GPS in there. Than you can use it all the time. Do not need to worry about long ..." | Read more » almost 9 years ago
Kaya9804 "Sure thing. I posted the PDF version because of how long it would take to upload, but I can change it if you'd like. " | Read more » almost 9 years ago
warren "Hi, Kaya - it'd be really helpful if you could copy/paste the images and text into the research note body, so it can be searched, etc -- do you thi..." | Read more » almost 9 years ago
mathew "I take it the idea is to get the red/blue flashing really fast, making a gradient red-->magenta--->blue depending on the resistance of the th..." | Read more » almost 9 years ago
donblair "Mathew -- AIR HOGS! Just watched the video -- WHUUUT!! We've got to do this! That's so much fun! We could be sampling the entire room remotely!..." | Read more » about 9 years ago
mathew "Sekjal, It would be really cool to have a rangefinder, but they're pricey sensors, and might significantly up the cost of the board. Don- I fixed ..." | Read more » about 9 years ago
sekjal "If we can determine the change in reading to be purely a function of distance alone, perhaps adding an ultrasonic rangefinder to the IR sensor/serv..." | Read more » about 9 years ago
donblair "Mathew -- I have never been so eager to follow a missing link -- where's the wall-climbing remote control toy car?! :) Wait a minute -- are you su..." | Read more » about 9 years ago
mathew "This is a really neat idea. thanks for working on this distance calibration. I have a stud finder that has felt on the bottom, and sounds similar..." | Read more » about 9 years ago
sekjal "There are Lego bricks for just about anything :) I was thinking that, since there are screw holes in the corners of the board already, flat topped..." | Read more » about 9 years ago
donblair "This is fantastic! I didn't know there were Lego parts that did that sort of height adjustment thing :) Your results are really important -- so n..." | Read more » about 9 years ago
ajawitz "RE- Through hole kits- Interestingly enough... It appears we're not the only one's talking about an ATmega32u4-based breakout as this Kickstarter ..." | Read more » over 9 years ago
donblair "Hi! Sorry for the delayed reply -- been a bit crazy with other projects, but still excited about this! On reflection, rather than add extra power..." | Read more » over 9 years ago
ajawitz " Do you have a link to the Visualight schematics? I should check them out, as Jeff was hoping to use their more powerful LED, and we might be abl..." | Read more » over 9 years ago
donblair "Woohoo! Quick replies / queries: Do you have a link to the Visualight schematics? I should check them out, as Jeff was hoping to use their more..." | Read more » over 9 years ago
ajawitz "Awesome! This is what I was hoping to see and then some. I don't think I've ever seen something go from brainstorm to schematic so quickly! I was..." | Read more » over 9 years ago
donblair "Jeff -- ah, I see -- good point! I don't think I'm finding the proper Visualight schematic ... file:///home/chronos/user/Downloads/strip_02-schema..." | Read more » over 9 years ago
warren "Also, did you do those completely rad illustrations? " | Read more » over 9 years ago
warren "Wow, Don - fantastic and super speedy work! One reason I was interested in the Visualight board was the strength of the LEDs -- really super brigh..." | Read more » over 9 years ago
warren "Hey Kaya, do you have any photos to share yet? " | Read more » about 10 years ago
mathew "Can't wait to see this. Make sure to put your antenna above water. Wifi is 2.4ghz like your microwave. water will stop it dead. " | Read more » about 10 years ago