Thermal flashlight Blog
Thermal flashlight design (+ thermal fishing bob, too?)
What I want to do
I'm trying to come up with a single-board prototype for Public Lab's Thermal Flashlight project. I'm trying to build on the great design ideas put forth in recent research notes -- the idea of adding a thermal flashlight shield to a Visuallight board, and the proposal to mash up the Sparkfun IR breakout board with a 32u4 processorand an RGB Led. I'm still rather new to designing boards, but I was inspired to do this mashup when I found Rui Wang's open source wearable computing project, which places an RGB, two rechargeable battery options (coin battery, or lipo via JST connector), and a piezo buzzer ('geiger counter' indications of temperature, whee!) all on a beautiful little board. Rui also added a light sensor, an ambient temperature sensor, a button, and has some nice large pin holes for attaching conductive thread. Those might be great things to include here, too, but I figured I'd drop them for now, for simplicity's sake.
My attempt and results
I've created a thermal flashlight board design github repo, where I'm working on an Eagle board. The basic layout idea was this:
Which, on the actual board, came out looking like this:
I've added four holes on the corners of the board -- I'm imagining that it can thus be attached to the end of a stick or cardboard tube, so that it feels like a 'flashlight' -- but then it occurred to me that it'd make a pretty cool "Iron Man"-style device, too:
Thermal fishing bob tie-in. I also figured that I should add a screw terminal to the board to allow for connecting a thermistor probe -- that way the same board could serve as a thermal fishing bob prototype (imagined here as simply sitting inside the translucent plastic 'powdered lemonade' container design, pioneered by Sara and Catherine):
Questions and next steps
Further work on layout and schematic. The design isn't finished yet -- still need to figure out the layout on the board, and I'm thinking that it might be a good idea to put breakout pins for a through-hole RGB LED for the thermal fishing bob case -- so that the LED could be bent at an angle and displaced away from the board, and would be more of a 'beacon' -- rather than being placed in the middle of the board. Also note: for the thermal fishing bob case, we could just opt not to place the IR sensor on the board, to make the design less expensive.
NOTE: in the github repo, the "32u4" design (which I think is where we should head) is the set of schematics / board designs that have "32u4" somewhere in the label.
Kit options. All of the board components are surface mount, except for the IR sensor and the screw terminal. So a good plan might be: have the board produced with only the surface mount components; then, when distributing a kit, include that board + a coin battery, and then additionally include a) the IR sensor, for a 'thermal flashlight' kit, or b) the screw terminal + a thermistor, for the 'thermal fishing bob' kit. Most folks could likely handle soldering those parts on themselves.
Anyone who knows something about Eagle design -- please feel free to download and tweak the board design and play around with the layout!
Why I'm interested
Seems like a single-sided, all-in-one thermal flashlight design would simplify production and reduce costs ... so here's my attempt at that ...
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thermal-photography thermal-flashlight water-quality thermal-fishing-bob
Thermal flashlight Visualight shield
What I want to do
In the comments of this post, we've been exploring how to make an expansion to the open source Visualight board to make it into a thermal flashlight. I had a rough Fritzing schematic but wanted to make a full board we could order with a bill of parts. Here's the original Fritzing diagram I made:
My attempt and results
I tried to make it in Upverter, which allows schematics and board files to be made online. I've never done this before but thought someone else might be able to fix my messy attempts.
https://upverter.com/jywarren/2de9afbe97ada5b1/Thermal-Visualight-shield/
The lead image is the unfinished PCB layout, and here's the schematic:
In the PCB (printed circuit board) layout, I tried to keep things compact, but unless I'm mistaken, we'll need a jumper or a double sided board with a single trace connecting the 2nd from bottom header pin to the top of the capacitor, where I've left a little mark. You can compare to the Fritzing sketch to see what I mean.
For reference, here are the hardware files for the Visualight: https://github.com/lpercifield/visualight/releases/tag/Hardware
Questions and next steps
I hope someone who knows how to use Upverter or something can help out... I'm also not sure if I've spec'ed the parts right or if the spacing of the header pins I've chosen matches those of the Visualight. I'm just new to this.
But we're so close, and at a quantity of 100, this seems to cost less than a dollar per piece for the board ($0.69) and the parts should cost <$10. Assembly, I don't know, but probably not much. The Visualight board at cost might be <$20, then batteries and such. This is looking feasible!
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thermal-photography thermal-flashlight visualight pcb
Thermal Flashlight Using MLX90614 IR Evaluation Board From Sparkfun
What I want to do
I would like to build a Thermal Flashlight that is very similar to the current recommended method on- http://publiclab.org/wiki/thermal-camera only instead of wiring in a standalone IR sensor, I would like to use the Evaluation Board for MLX90614 IR Thermometer from Sparkfun.
The advantage of using the evaluation board over the standalone component is the board includes its own ATMega328 chip. In other words, you don't need to connect it to an Arduino Uno because it already has one embedded into it on a much smaller footprint. This should make it much easier to do what this guy was trying to do on Instructables-http://www.instructables.com/id/Build-a-Thermal-Flashlight-Light-Painting-with-T/ only without having to stuff an entire Arduino Uno into the flashlight body. Additionally, it might help with the Visualight project by serving as a template for replacing the ATMega328 with a USB-capable chip like the ATMega32u4 or an ATTiny84.
Questions
Even though the included "example sketch" from Sparkfun isn't even written for Arduino, it works out of the box with the same sketch that the Thermal Flashlight is based on at- http://bildr.org/2011/02/mlx90614-arduino/
Because the ATMega328 can not communicate via USB by itself, it has to be connected through an FTDI-Serial adapter like Adafruit's "FTDI Friend" or SeeedStudio's "UArtsBee" which is what I'm using. The Arduino IDE must be set to connect to an "Arduino Pro/Pro Mini (3.3v 8 MHz)w/ATmega328" and the temperature readings will start streaming to the serial monitor at 9600 Baud. So far so good. Now the tricky part is outputting these values to the RGB LEDs. Sparkfun did include at least four analog/digital outputs labelled "PC0-PC4" along with "SCL" and "SDA' for serial. Unfortunately, simply changing the "int REDPin" from "6" to "PC2" etc... in the Arduino Sketch didn't seem to work.
However, I was able to use the eval board as if it were a standalone sensor by connecting 3.3v + GND, SCL to A5 on the Arduino and SDA to A4 on the Arduino.
Next Steps
EDIT: While I've been able to complete the circuit by connecting the eval board to an Arduino Uno as if it were a standalone sensor, this still doesn't achieve my goal of reducing the overall footprint so as to fit inside a modified flashlight. As an interim step, I'll see if I can replace an Arduino Uno with an Arduino Micro which will reduce the footprint significantly, though not as much as if I can finally figure out how to enable the Eval Boards outputs for the RGB LEDs.
As the Micro is based on an ATmega32u4, it will also help test any hypothesis about upgrading the Eval Board to work with USB support.
There is a Schematic for the IR Eval Board-
Or it can be found at this link.
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thermal-photography thermal-flashlight thermal-camera tool
Thermal Flashlight from hacked, off-the-shelf Pocket IR Thermometer
What I want to do
I would like to hack an off-the-shelf IR Thermometer found at any Radio Shack (link and image below) for use as a cheaper an more accessible component in the thermal flashlight build. In northeastern states like Maine, it goes without saying that home heating is a major concern. Ever since installing a small Pellet Stove in my basement, I've been looking for ways to increase its effectiveness by controlling the household airflow. While our reliance on propane fuel has decreased dramatically, without any cost effective means of visualizing and/or controlling airflow, we're more or less flying blind. The long term solution is to build a wireless sensor network via wifi and XBee's that will log temperature readings from various fixed locations around the house while also allowing for remote control of things like fans, electric heaters and even the pellet stove itself! Before that can happen though I need to get a better idea of where to set up the sensors. For this I need a thermal imager of some sort. Obviously, I'm not about to fork out +$1000 for a proper flir cam, so I was happy to see the thermal camera work done here on PublicLab. Yet, Its been many months since I first found the Thermal Camera build instructions and I still havent gone anywhere with it. Why? At $20 for a required minimum of two Melexis IR Sensor is a tad pricey for for something I'm not likely to use in any other projects. If it was something I could just pick up at the local Radio Shack, it would be a different story however. So when I noticed Radio Shack selling their own commercial "Pocket IR Thermometer" for $10, this is precisely what I had in mind!
My attempt and results
Before doing anything I thought I would search the usual places (Instructables, Hack-A-Day etc...) for any existing hacks but searches for "Radio Shack IR Thermometer" turned up a lot of nothing. The user manual covers the basics but nothing more than how to turn it on and where the batteries go.
The cover came off relatively easily, and the circuitry resembles a long stick of gum with a sensor on the end that looks suspiciously similar to the Melexis MLX14. I was able to make out the words "ZyTemp TNOpm2" and this turned out to be the clue I was hoping for! Not only was I able to find the full detailed datasheet at- http://www.zytemp.com/products/tn0pm2.asp but thanks to some savvy EV enthusiasts (over on endless-sphere) I was able to find a detailed post outlining the pinouts to get a serial connection with an Arduino- http://endless-sphere.com/forums/viewtopic.php?f=7&t=49058
The instructions on the thread are for a different model however, so I didnt know if it would work for mine. The pinouts were big enough for me to easily add a header and the assignments appear to be the same as the endless-sphere build-
V= Vdd G = GND D = Data (serial) C = Clock (for data) A = Action Pin (pull to GND to take a measurement. Shorting to ground will make it do continuous measurements)
Questions and next steps
Having worked endless hours trying to get an Arduino IDE on Ubuntu to recognize the serial port of a Leonardo-type (Software Serial) device, simply getting a read-out on a serial monitor is a huge win! Now the next step is for it to make sense.
Right now the Serial Monitor seems to be spitting out an uncalibrated number in both Celsius and Fahrenheit-
99.00 C 210.20 F
99.00 C 210.20 F....
I'm guessing, I have to mess with the software interrupts a little bit so the ss knows what to grab.
Once thats taken care of, it should be relatively straight-forward to either merge with the current Thermal Flashlight sketch, or configure my own range of RGB LED outputs.
Thus Far the baseline sketch I've been using is based on "http://dorkbotpdx.org/blog/scott_d/inexpensive_ir_based_temperature_sensor_for_microprocessors"
The small form factor of the Arduino Micro allows for any number of cam/controller combinations. Depending on the usage I might try it with the new Adafruit "Trinket" ATTiny85 microcontrollers which would almost allow it to fit back into its original case.
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thermal-photography thermal-flashlight thermal-camera tool
MQI Environmental Recorder
MQI Recorder is now available for pre-order via Citizen Scientific Workshop and a portion of the proceeds of each unit will be donated to help support Public Lab. My quest to build an easy to assemble, use, and hack multi-function environmental recorder. Made using open hardware an household materials.
The MQI currently carries a thermal flashlight, and two gas sensors. It is derived from the thermal photography project here on Public Lab, and inspired by other projects such as citizen air quality mapping projects like FLOAT. My desires were to create the beginnings of an expandable platform built to enable people everywhere to record data from their environment, and with the included MQI mobile app (in development) share that data to maps and locations via the internet.
The MQI defaults to the thermal flashlight mode, and pressing one of the two buttons switched the RGB LED to display each of the gas sensors with the same mapping function as the thermal flashlight.
Currently the MQI carries a functioning IR thermometer, MQ-2 for Methane, Butane, LPG, and smoke, and MQ-7 for Carbon Monoxide. Any sensors can be used, and I am currently pondering what might be the most beneficial combinations.
UPDATE 1/14/14 _ Finished up a nice acrylic case for the MQI, Transparent is my favorite color, it shows all of the blinky lights. I think that both a papercraft version and more permanent acrylic or wood case will be nice, as one can save on cost, and the other can encase the unit when strapped to a kite, or taped on top of your car or something... ;)
We have made some significant progress on the app as well, a demo version of which is also available here:
Builder's Tutorial is coming soon.
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indoor-air-quality-mapping thermal-flashlight methane natural-gas
Visualight board for Thermal Flashlights
What I want to do
Leif Percifield's Visualight is an affordable Arduino-compatible USB-stick with a powerful RGB LED on it -- perfect for a thermal flashlight! So I jumped into just getting the colors to change. I'll try something with the Melexis infrared sensor later, but Leif left i2c pins open specifically so that we at Public Lab could connect such sensors! It's also open source. Leif is the best.
My attempt and results
I made this Arduino sketch: https://gist.github.com/jywarren/7488213
It just blinks each LED in succession; real simple.
Questions and next steps
Next up: connecting a power source (just a 2 AA battery USB power source) and the IR sensor. This thing is so compact, it'll fit nicely into a tube or other enclosure.
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thermal-photography arduino thermal-flashlight led