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Coqui conductivity sensor

## What Does It Do? **The Coqui: a simple device to read a sensor via an audible tone.** We're exploring using audio frequencies to convey sensor readings -- like a modem, but even simpler -- in order to make sensor readings more accessible for people (or to enable data transmission over ubiquitous audio jacks on PCs and smartphones). ## Latest version The [latest and simplest version of the Coqui](/notes/warren/03-01-2019/build-a-sound-generating-coqui-conductivity-sensor) can be seen in the following images. This version differs from [the previous](/notes/ashkaya/09-17-2016/build-a-coqui-a-simple-water-conductivity-sensor) in a few ways: * smaller, cheaper circuitboard (breadboard) * fewer wires * flatter wires which make it easier to see the circuit However, the circuit is fundamentally the same! Click these images to enlarge: [![IMG_20190123_111639_270.jpg](/i/28988?size=medium)](/i/28988?size=original) [![IMG_20190118_205609_421.jpg](/i/32338?s=m)](/i/32338?s=o) ## Assemble the Coqui Here are a few guides to building different versions of the Coqui: [notes:grid:activity:coqui] ## Coqui versions The Coqui has been refined, remixed, and modified plenty over the years. [activities:coqui-version] ## Modify the Coqui [activities:coqui-mods] ## Do something with the Coqui Once you've built a Coqui, here are a few things you can do with it: [notes:grid:activity:coqui-usage] Add an activity or request an activity guide you don't see listed **** ## Frequently Asked Questions [questions:coqui] **** [![coquibb.JPG](]( A Coqui is a simple, inexpensive, open source device that generates an audible tone that is based on any electric resistance-based measurement. For example, a Coqui can measure: * conductivity of liquids * temperature * ambient light ## Build a Coqui Instructions on the breadboard-based "BBv1.0" edition of the Coqui can be found here: ### Notes - The github repo for a more permanent printed circuit board version of the coqui is [here]( The Coquí is a circuit that allows you to 'hear' the readings from various sensors. Once the Coquí is assembled, you'll be able to 'hear' the conductivity of a solution, the temperature of a room, or the color of a pH test strip. The design was named (onomatopeically) after the several species of small frogs which have a loud, distinctive call at night. ### Demo Coqui applications - [Testing the conductivity of a solution]( - [Reacting to an LED with sound]( - [Assessing ambient light levels]( - [Assessing temperature with a thermistor]( - [Sending water quality voicemails with a coqui using]( [![water-vmail.png](]( ### Building your own Coqui - [Coqui BBv1.0]( a breadboarded version of the Coqui ### Building Coqui sensors - Making a conductivity probe from a [bottle cap and two metal screws]( ## Parts list See the initial parts list here: #13459 and #11209 for a DigiKey shopping cart link at $19 per kit. And @kanarinka mentions: > there are a couple other things that are helpful to have that are not shown (like the probe made from the top of a water bottle with two screws in it and alligator clips to attach that to the breadboard) Scans of an invoice from DigiKey: [![Screenshot_2018-02-28_at_9.59.17_AM.png](]( [![Screenshot_2018-02-28_at_9.59.46_AM.png](]( ...

Author Comment Last activity Moderation
mathew "yes. we should. It isn't directly evident why we would use audio, given that it is so incredibly data-intensive. We have to make that argument RE:..." | Read more » about 9 years ago
donblair "Aw, shucks :) But yes, it's so cool that we might find some part of design solution space that satisfies all of these! Before Ben pointing me to t..." | Read more » about 9 years ago
mathew "Your diligence in solving this calibration problem in the most user-friendly way that ALSO involves simplifying the electronics AND the signal out..." | Read more » about 9 years ago
donblair "Here's an example of a cheap, through-hole 'trimmer capacitor':" | Read more » about 9 years ago
boczniak "very good news :) " | Read more » about 9 years ago
donblair "Ah darnit, I deleted my comment above by accident, instead of editing it ... Okay, the punchline is: The only ways to compensate for the effect t..." | Read more » about 9 years ago
donblair "My endocrine system can't handle all of these ups and downs. But tonight ends on an up. " | Read more » about 9 years ago
donblair "UPDATE: We can dial in the capacitance! Ben pointed me to the fact that 'trimmers' exist:" | Read more » about 9 years ago
donblair "Yes! And before, when we had a different relationship between freq and conductivity, the only way to do that tuning was to tweak the probe -- and J..." | Read more » about 9 years ago
mathew "this is super excellent. does this mean that people can assemble DIY probes with slightly different relationships that we can now tune to standard..." | Read more » about 9 years ago
donblair "(maybe that should prompt me to reconsider my life direction?) " | Read more » about 9 years ago
donblair "YES! :) I was dancing around with glee last night when I saw the equation for freq vs. resistance and capacitance for the 50% duty cycle! " | Read more » about 9 years ago
warren "This is great news!!! And well presented! " | Read more » about 9 years ago
btbonval "Recently bumped into this: Haven't looked much into it, but the front page shows there are some collaboration tools as par..." | Read more » about 9 years ago
mathew "I'm fully in support of distributing proto-boarded Coqui's over circuit boards, mainly because we may need to add parts/change the resistor and cap..." | Read more » about 9 years ago
mathew "Upverter is nice, Eagle is just as user-friendly as a CAD software from the 80's is expected to be... We should find someone to give us all a KiCAD..." | Read more » about 9 years ago
warren "Great, thanks Don. I can change the title/body to reflect whatever name you think is more appropriate -- "Coqui-based water conductivity sensor"? ..." | Read more » about 9 years ago
btbonval "I hadn't heard of upverter. Adafruit has been pushing Eagle software, which is non-libre and has a cost. I've been seeing a lot of Eagle usage in ..." | Read more » about 9 years ago
donblair "Ah, this is all so great! This brings up a bunch of interesting issue for me that I'd love to get feedback on. Naming conventions. Maybe it'd be..." | Read more » about 9 years ago
kanarinka "Hey @warren @donblair and Katie - Nice work - this is simple and exciting. we did a home brewed test of Coquí here last weekend with hot/cold water..." | Read more » about 9 years ago
cfastie "The first time i have ever found a tree frog in my house was at the LEAFFEST where the Coqui was built, tested, and designed for PCB. . . Clearly..." | Read more » about 9 years ago
kgradow1 "Markdown This looks really good! " | Read more » about 9 years ago
lilybui "Some open source spectral analysis software to check out. (I like this one because it translates into 19 different languages.) ht..." | Read more » about 9 years ago
mathew "This is most excellent. I especially like how accessible audio analysis is. Pure Data is a great FOSS system for doing audio analysis, has built-..." | Read more » about 9 years ago