Public Lab Wiki documentation



Coqui conductivity sensor

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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). Look for recent updates on Public Lab here.

Latest version

We'll be posting an update soon but the latest and simplest version of the Coqui can be seen in these images as well as the attached printable circuit diagram file. CoquiFeb19_bb.png

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Activities

This is a list of community-generated guides for specific applications using your coqui. These activities can be categorized, and some may be more reproduced -- or reproducible -- than others. Try them out to build your skills, and help improve them by leaving comments. Together, we can repeat and refine the activities into experiments.

Purpose Category Status Author Time Difficulty Replications
Build a sound-generating Coqui conductivity sensor (new version!) - - @warren - - 2 replications: Try it »
Building the new Coqui - - @natevw - - 0 replications: Try it »
Coqui 文件 - - @imvec - - 0 replications: Try it »
Build a Coquí: A Simple Water Conductivity Sensor (version 1) build review-me @akshaya 1h easy 3 replications: Try it »
¿Cómo hago una serie de diluciones para calibrar un Coqui para medir sólidos disueltos totales (STD)? - - @alejobonifacio - - 0 replications: Try it »
Construya un sensor de conductividad Coqui generador de sonido - - @alejobonifacio - - 0 replications: Try it »
Analizar señal de audio del sensor Coqui con Audacity - - @imvec - - 0 replications: Try it »
Build a "Mega Coqui" water conductivity sensor with an amplifier - - @warren - - 0 replications: Try it »
Añadir clavija al sensor Coqui para grabar las mediciones - - @imvec - - 0 replications: Try it »
Grabar muestras de audio del sensor Coqui - - @imvec - - 0 replications: Try it »

Activities should include a materials list, costs and a step-by-step guide to construction with photos. Learn what makes a good activity here.


Frequently Asked Questions

Title Author Updated Likes Comments
How can we adjust the volume of the coqui? @liz over 5 years ago 7
How can we adjust the frequency of the coqui? @liz over 5 years ago 3
Did anyone feel a strong heating of the buzzer in the Coqui sensor? is too hot @alejobonifacio about 2 years ago 0
Why does my coqui not change frequency in salt water anymore? @stevie almost 4 years ago 2
Can anyone tell what is wrong with my coqui? @stevie almost 5 years ago 13
DIY Salinity Measurements with Coqui and/or Multimeter? @Bronwen about 5 years ago 3
Can we use a guitar tuning app to get numeric data from the Coqui water sensor? @warren about 5 years ago 4
Could we just use the PWM feature of an Arduino to generate the 50% duty cycle we need for the Coqui or for a water conductivity meter? @roberts_ecofarm over 5 years ago 3
Will this single timer work for the coqui? @asnow almost 6 years ago 5
How much are Coqui measurements affected by hot/cold water? @warren over 9 years ago 14
Accessible procedure for calibrating conductivity measurements? @donblair over 9 years ago 3


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

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

water-vmail.png

Building your own Coqui

Building Coqui sensors

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

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