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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
pdhixenbaugh "@kgradow1 I'm having trouble finding the coqui activity grid. Could you link to it? " | Read more » about 7 years ago
kgradow1 "Accidentally posted this on the coqui activity grid and looks like I can't remove it. Help? " | Read more » about 7 years ago
kanarinka "Thanks @warren! @kgradow1 - this is a great suggestion for improvement as I've also had that happen. How about @akshaya and I will make a digikey s..." | Read more » about 7 years ago
kgradow1 "This is a great overview! One suggested edit: Include an explanation of how component variability might impact the circuit. I've tried to build th..." | Read more » about 7 years ago
warren "Hi, I reposted this from -- to make it into an activity that can be featured in..." | Read more » about 7 years ago
donblair "Hi Rebeccah! Fantastic stuff here. Lots to digest, and I have several thoughts -- but first, quickly: the frequency output of the Coqui requires..." | Read more » about 7 years ago
cfastie "Hi Rebeccah, Just in case this can explain the problems when using the proto board, are you aware that the proto board for the Riffle has its pins..." | Read more » about 7 years ago
pdhixenbaugh "Hello Rebeccah! I'm interested in replicating this experiment! The biggest thing I am unsure about is the code - can you link to the riffle code yo..." | Read more » about 7 years ago
warren "Hi, Rebeccah -- looks like your lead image didn't work -- maybe try again, or email it to if you can't get it to upload? I'm int..." | Read more » about 7 years ago
liz "Here's a report back (including video!) from a workshop led by John Keefe in August 2015 " | Read more » over 7 years ago
cfastie "For $25 that hydro generator has got to be a good thing. It is an impartial solution for my spring house because it can't freeze (operating range 4..." | Read more » over 7 years ago
donblair "Oh, exciting ... it'd be fun to demonstrate anything powered by moving water. Maybe this thingy should be ordered immediately. A visit ASAP sound..." | Read more » over 7 years ago
cfastie "That hydro generator says it needs 3 liters per minute, which we have. Sorry about revealing your irrelevance. Also, we wouldn't need the internet..." | Read more » over 7 years ago
donblair "Exactly. Was confusing for me, too, as I'd been nursing a rather fixed mental picture of a parallel plate capacitor with a dielectric slab sandwic..." | Read more » over 7 years ago
cfastie "Why does this work when the two wires (the extension cord) are insulated? It must be that the electric field extends outside the wires into the wat..." | Read more » over 7 years ago
donblair "This sounds like it might prompt a PVOS research trip up to Bernie Country ... I need to write up a research note, but here's the basic idea (cour..." | Read more » over 7 years ago
cfastie "Don have you described somewhere how in the world this thing measures water depth? I need this and I discovered today that my spring house up in th..." | Read more » over 7 years ago
donblair "Hi @gretchengehrke :) I'd never really testing it very thoroughly, and I haven't done sufficient background research to know if the 555 approach I..." | Read more » over 7 years ago
gretchengehrke "Hey Don -- How well does the depth feature work? @stevie and I were just talking about it, and are needing a reminder. :) " | Read more » over 7 years ago
liz "@taramei check this out for your venus flytrap work in brackish water!!!!! " | Read more » over 7 years ago
pdhixenbaugh "Other people have commented elsewhere how "trimmers" (capacitors with adjustable capacitance) exist, which would be a useful way to "tune" the soun..." | Read more » over 7 years ago
liz "Ok great, thank you for the feedback! My next workshop is a demo only, so the voltage / electrolysis issue won't matter in this case thank goodness..." | Read more » over 7 years ago
donblair "Hey Liz! Wow -- this looks great! Since this research note was originally posted, there are a few insights that have emerged: Silicone doesn't ..." | Read more » over 7 years ago
liz "So, I'm making 15 of these conductivity probes to go along with the Digikey order that makes 15 Coquis. Last night cut open 15 plastic bottles with..." | Read more » over 7 years ago