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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
warren "Yeah, it works fine, it's a bit louder which is nice.  On Sun, Apr 7, 2019, 4:21 PM \<> wrote: Hi! You were ment..." | Read more » about 4 years ago
Bronwen " Ah ha! Glad it's working out. We'll make a note that the timer might be the issue if you're getting noise, but not the RIGHT noise. In retrospect ..." | Read more » about 4 years ago
stevie " Coffee's gone now. I've moved on to salt water :laughing: " | Read more » about 4 years ago
zengirl2 " Wow so weird! Sometimes the legs can get bent on those--anyway, so glad it's working. You should post a video so we can hear the sound of the coff..." | Read more » about 4 years ago
stevie " It was the timer!! I replaced it and it works now " | Read more » about 4 years ago
zengirl2 " I'm still learning about how to know whether circuits can handle voltage, but so far it looks like the 555 timer probably is fine, but not sure ab..." | Read more » about 4 years ago
stevie "Oh interesting. This is the only way I have to hook up a battery right now. Switched out the wires into the (yes Haha) coffee, still not working. ..." | Read more » about 4 years ago
stevie " Hm.. yeah I've taken it apart and put it back together with new wires. Still not working " | Read more » about 4 years ago
zengirl2 "Oh hey, what about voltage? I just remembered that we were using 2-AA batteries which would only be 3V and you are using a 9V. Can the chip handle ..." | Read more » about 4 years ago
zengirl2 " I agree that your setup looks good. Of course you could test your battery to see if it's fresh. The only other thing besides making sure connectio..." | Read more » about 4 years ago
Bronwen " I've experienced this before, and generally it's resolved when I went through and double checked and repositioned the wires-- it could be that som..." | Read more » about 4 years ago
stevie " The black dot is in the right place. " | Read more » about 4 years ago
warren "Hmm, it looks perfect compared to the one at #coqui. Is the little dot/depression on the black chip in the upper left position? Is it possible it's..." | Read more » about 4 years ago
ufagroup_ufagroup "WOW GOOD JOBB แทงบอล " | Read more » about 4 years ago
warren " I made a sketch of an equalizer -- you can also hover your mouse to see the frequency:" | Read more » about 4 years ago
warren " From a great suggestion from @mimiss I dug up an EQ or equalizer visualization from" | Read more » about 4 years ago
warren "Noting here, a couple ways to approach analyzing Coqui audio data:" | Read more » about 4 years ago
Ag8n " You can buy the instruments with a microprocessor attached. All you have to do is take a syringe, put the liquid in the glass tube, and it will r..." | Read more » about 4 years ago
Bronwen " Oh wow, thanks! This is really helpful, I'll look into the tuning fork method. " | Read more » about 4 years ago
Ag8n " The reason multimeters aren't used for measuring the resistance of a solution is polarization. It's a fancy word, but by passing direct current t..." | Read more » about 4 years ago
warren " I also found recently that a more powerful battery makes it louder, which i guess i could've figured out from the comments above (lol) but, just t..." | Read more » about 4 years ago
warren " I think it's possible, yeah! I'm not sure how fast PWM is or how easily you can set the rate? " | Read more » over 4 years ago
warren "I was also able to confirm that adding a resistor in-line with one of the probe wires lowered the frequency! Much lower and less annoying! " | Read more » over 4 years ago
xose "Hi @Liz! A potentiometer just before the probe changes tone. And, for a higher volume you can substitute the piezo speaker with a minijack connecto..." | Read more » over 4 years ago