## 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/28989?size=medium)](/i/28989?size=original)



## 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]


[button:Add an activity:/post?tags=activity:coqui-usage,coqui,water-quality,seeks:replications&title=How%20to%20do%20X]  or request an activity guide you don't see listed



****

## Frequently Asked Questions

[questions:coqui]

****

[![coquibb.JPG](https://i.publiclab.org/system/images/photos/000/007/410/medium/coquibb.JPG)](https://i.publiclab.org/system/images/photos/000/007/410/original/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:

http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0

### Notes

- The github repo for a more permanent printed circuit board version of the coqui is [here](https://github.com/OpenWaterProject/coqui)

The Coqu&iacute; is a circuit that allows you to 'hear' the readings from various sensors.  Once the Coqu&iacute; 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. </br></br>

The design was named (onomatopeically) after the <a href="http://en.wikipedia.org/wiki/Coqu%C3%AD">several species of small frogs </a> which have a loud, distinctive call at night.</br></br>

<iframe src="//player.vimeo.com/video/100778803?title=0&amp;byline=0&amp;portrait=0" width="600" height="393" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

### Demo Coqui applications

- [Testing the conductivity of a solution](http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0-testing-conductivity-of-a-solution):

<iframe width="560" height="315" src="//www.youtube.com/embed/Txu08bFOpaU?list=UUmmEmOGni0fzzDsXiZEVWNw" frameborder="0" allowfullscreen></iframe>

- [Reacting to an LED with sound](http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0-reacting-to-an-led-with-sound):

<iframe width="560" height="315" src="//www.youtube.com/embed/Snr0Zd8oueE?list=UUmmEmOGni0fzzDsXiZEVWNw" frameborder="0" allowfullscreen></iframe>

- [Assessing ambient light levels](http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0-assessing-ambient-light-with-a-photoresistor):

<iframe width="560" height="315" src="//www.youtube.com/embed/S1GoPiRVTD0?list=UUmmEmOGni0fzzDsXiZEVWNw" framebordhttps://i.publiclab.org/system/images/photos/000/007/409/original/water-vmail.pnger="0" allowfullscreen></iframe>

- [Assessing temperature with a thermistor](http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0-using-a-thermistor-as-a-temperature-probe):

<iframe width="560" height="315" src="//www.youtube.com/embed/cvWfdVbV_08?list=UUmmEmOGni0fzzDsXiZEVWNw" frameborder="0" allowfullscreen></iframe>

- [Sending water quality voicemails with a coqui using vojo.com](http://publiclab.org/notes/donblair/09-10-2014/water-quality-coqui-voicemails):

[![water-vmail.png](https://i.publiclab.org/system/images/photos/000/007/409/medium/water-vmail.png)](http://publiclab.org/notes/donblair/09-10-2014/water-quality-coqui-voicemails)


### Building your own Coqui

- [Coqui BBv1.0](http://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0): a breadboarded version of the Coqui

### Building Coqui sensors

- Making a conductivity probe from a [bottle cap and two metal screws](http://publiclab.org/notes/donblair/09-30-2014/making-a-diy-conductivity-probe-from-a-water-bottle-and-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](https://publiclab.org/system/images/photos/000/023/760/large/Screenshot_2018-02-28_at_9.59.17_AM.png)](https://publiclab.org/system/images/photos/000/023/760/original/Screenshot_2018-02-28_at_9.59.17_AM.png)


[![Screenshot_2018-02-28_at_9.59.46_AM.png](https://publiclab.org/system/images/photos/000/023/761/large/Screenshot_2018-02-28_at_9.59.46_AM.png)](https://publiclab.org/system/images/photos/000/023/761/original/Screenshot_2018-02-28_at_9.59.46_AM.png)