Summary of PHduino pH Meter Using Arduino
This project describes pHduino v0.2, an open-hardware and open-software pH meter built around an Arduino/Freeduino that interfaces with a glass electrode pH sensor, displays pH and temperature on an LCD or via USB to a computer, and uses trimpots for gain/offset and temperature compensation. It aims to be simple, modifiable, and expandable rather than a high-end analytical instrument. Releases, firmware/hardware versions, and licensing (PCB CC BY 3.0, code GPLv2) are noted.
Parts used in the pHduino v0.2:
- Arduino or Freeduino board
- Glass electrode pH sensor (pH electrode)
- LCD display
- USB interface (for computer connection)
- Trimpots for signal gain (slope) and offset adjustment
- Temperature sensor for compensation
- PCB (layout provided under Creative Commons)
- Supporting firmware/software (GPLv2)
- Optional datalogger hardware
About
This project describes an open software open hardware pH meter using an Arduino/Freeduino board. In other words, this is an electronic circuit to be connected with a glass electrode pH sensor.
It was possible by the idea from my friend Mr. Denis Vidal, the space that my supervisor gave me, prof. Dr. Emanuel Carrilho, BioMicS Group, Instituto de Química de São Carlos, Universidade de São Paulo, Brazil, and by facilities and suggestions from prof. Dr. Claudimir Lucio do Lago, LAIA Laboratory, Instituto de Química da Universidade de São Paulo, Brazil. Thanks Fapesp – Fundação de Amparo à Pesquisa do Estado de São Paulo by the financial support for my different projects during my academic life.
De pHduino v0.2
Importance and Applications
pH is a very important property in aqueous solutions. The pH is defined the colog (-log) of the hydrogen ion (H+) activity in the medium (or concentration when the H+ is low quantity). This property indicates if the medium is acid, neutral, or basic.
For example, it is necessary control the pH of an aquarium. Some species of fish can not live out of a range of pH. So, we need read it and make the write correction of the pH. Other areas or applications where is important to know the pH are hydroponic, fermentation processes like beer and wine production, environmental monitoring of soils, water of rivers, lakes, and rain, sewage treatment tanks, monitoring of solution and buffers in laboratories of chemistry, and etc.
Overview
The pHduino can operate using a LCD to display the pH and the temperature data like a pH meter. Also, you can control it using a computer by USB port.
The signal gain (slope) and the signal offset are adjusted manually by trimpots. The signal is compensated by a temperature sensor.
It seems inferior and a little bit more expensive compared with a pH meter bench instrument. However, it is interfaceable, programmable, expansible, and, the more important, open and free!
Again, it is not intent to be a high resolution analytical instrument to compete with a commercial pH meter. It is to be simple, easy to understand, easy to modify, and different!
News
- 2012-07-13 Released Python Jabberbot script v0.1.
- 2012-03-12 Arduino 1.0 compatible.
- 2011-01-01 pHduino Datalogger hardware v0.1 and firmware v0.4.1-0.3 released.
- 2010-09-07 Released new hardware v0.2_0.3 and gerber files package v0.1.
- 2010-04-25 Released pYpHpoT v0.1.
- 2010-04-21 Released firmware v0.4.1.
- 2009-09-20 Released firmware v0.4.
- 2009-09-13 Released firmware v0.3.
- 2009-08-31 Released hardware v0.2 and firmware v0.2.
- 2009-08-12 First public release of the electronic circuit.
- 2009-08-04 Project opened.
License
The layout PCB is under Creative Commons 3.0 and the source code under GPLv2.
For more detail: PHduino pH Meter Using Arduino
- What is pHduino v0.2?
An open software and open hardware pH meter using an Arduino/Freeduino board designed to read a glass electrode pH sensor and display pH and temperature. - Can pHduino display temperature?
Yes, it displays temperature and uses a temperature sensor for compensation. - How is the signal gain and offset adjusted?
The signal gain (slope) and offset are adjusted manually by trimpots. - Does pHduino connect to a computer?
Yes, it can be controlled using a computer via the USB port. - Is pHduino intended to replace commercial high-resolution pH meters?
No, it is not intended to compete with commercial high-resolution analytical instruments; it is meant to be simple, modifiable, and expandable. - What licenses cover the project?
The PCB layout is under Creative Commons 3.0 and the source code is under GPLv2. - Are firmware and hardware releases available?
Yes, multiple hardware and firmware versions and releases are listed, including datalogger hardware and firmware releases. - Is the project open for modification and expansion?
Yes, the project is open and free, designed to be interfaceable, programmable, and expandable.
