tag:blogger.com,1999:blog-10337211544985185422012-01-22T20:54:54.164-02:00Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-1033721154498518542.post-68790654937021438232011-01-01T20:48:00.000-02:002011-01-01T20:48:08.821-02:002011-01-01T20:48:08.821-02:00

Feliz Ano Novo! De pHduino Datalogger At the begin of the 2010, I developed a datalogger shield for the pHduino. Again, I decided to make something simple to mount, modify, and use. I put the project in stand by because I need improve the code. Yesterday, I resolved make the modifications and I released it today. You can download the hardware and firmware files from the page of the project.

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com2tag:blogger.com,1999:blog-1033721154498518542.post-66914835260883478512010-09-07T21:17:00.000-03:002010-09-07T21:17:14.513-03:002010-09-07T21:17:14.513-03:00

Olá. I have received some e-mails about people interested to buy a pHduino shield. But, I can't sell it, yet. The reason is I used the Eagle Free version (I can't make money with this version). Another reason is the business tax is very hard here in Brazil. Therefore, it is better you make your our PCB shield. I will resolve this problem in the next version. Today, it is easy to make a PCB at

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com6tag:blogger.com,1999:blog-1033721154498518542.post-60433636725196880532010-04-25T22:41:00.003-03:002010-04-25T22:46:27.858-03:002010-04-25T22:46:27.858-03:00

Olá. This post is about first release of the pYpHpoT python script. It is a simple python script that reads the data from the pHduino and plots and saves the data to a text file. The Graphical User Interface (GUI) Up to now, the data from the pHduino were presented in the serial terminal. A good serial terminal has an option to save the data to a text file. But, they can not plot them. So, I

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com2tag:blogger.com,1999:blog-1033721154498518542.post-50891753692496406732010-04-21T13:07:00.001-03:002010-04-25T22:44:54.713-03:002010-04-25T22:44:54.713-03:00

Hi everybody. It is a newest release of the pHduino firmware with some little modifications. The most import addition is a magic number to simplify the pHduino operation. Changelog v04_20100421 Removed duplicated unsigned word from readADC function. Added magic number for check empty memory or different data block. Clean up of version strings. Magic Number Let's suppose you just mounted a new

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com2tag:blogger.com,1999:blog-1033721154498518542.post-53566683444338907922010-02-17T13:59:00.001-02:002010-02-18T12:44:40.355-02:002010-02-18T12:44:40.355-02:00

This post describes how to sold a high impedance terminal for a potentiometric measurement. The problem pH measurement, using glass electrode, is a technique which we read an electric potential difference without consume electric current. In fact, it is impossible not consume current. Every measurement system consumes some electric current. In this case, we need select an operational amplifier

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com2tag:blogger.com,1999:blog-1033721154498518542.post-58895821285852549282009-09-20T20:35:00.001-03:002009-09-24T13:31:39.111-03:002009-09-24T13:31:39.111-03:00

Again, one more pHduino firmware release. Two main features: pH alarm, to warn when the pH is out of the normal range, and save parameters in the Arduino EEPROM memory, to recover the last configuration after a reset or a power off. Changelog v04_20090920 Changed file name from phduino.h to pHduino.h. Added codename version. Added function to set the pH range for the pH alarm.  Added pH

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com9tag:blogger.com,1999:blog-1033721154498518542.post-6300368222801220032009-09-13T19:45:00.009-03:002009-09-13T20:40:42.259-03:002009-09-13T20:40:42.259-03:00

This is the newest version of the pHduino firmware. Now you can configure it using a serial port communication.Fixed comment about time of one 60Hz cycle in phduino.h file.Added time for 50Hz power line.Added command line feature to configure the pHduino.Added option to work without temperature sensor by setting a temperature value by command line.Added option to configure the time interval

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com0tag:blogger.com,1999:blog-1033721154498518542.post-38699802421390484122009-08-30T21:09:00.009-03:002009-09-01T00:14:01.047-03:002009-09-01T00:14:01.047-03:00

A new pHduino hardware version was released. The problem about sensor voltage offset compensantion was resolved. See the changelog for the changes.Changelog - Hardware version 0.2Fixed the problem of the offset signal amplification before the compensation.Increase the value of the resistors to reduce the electric current consume (Dr. do Lago).Changed the charge pump inverter capacitors from

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com9tag:blogger.com,1999:blog-1033721154498518542.post-13469219371655452702009-08-17T21:12:00.006-03:002009-08-17T21:47:39.341-03:002009-08-17T21:47:39.341-03:00

I said that I decided change the gain stage from a trimpot to a resistor to simply the calculus, but now I made a mistake about the gain stage.My first version used a trimpot for the offset stage and another one to the gain stage. In this configuration I can adjust the signal with freedom. The code is simple and easy to change. But, I can determine exactly the gain value. This is the point

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com5tag:blogger.com,1999:blog-1033721154498518542.post-77439165529901850052009-08-11T23:38:00.000-03:002009-08-11T23:59:10.877-03:002009-08-11T23:59:10.877-03:00

I am really sorry about the delay. But, just before to publish the electronic schemes and the PCB layout I decided to make some changes. Now I published the first public version of the pHduino hardware scheme and PCB. I have a code example but I need clean it up.One change was remove a gain adjust trimpot to a fixed value resistor. This change makes me know exactly the voltage of the glass

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com0tag:blogger.com,1999:blog-1033721154498518542.post-65647845841380589692009-08-04T23:22:00.000-03:002009-08-05T01:48:16.700-03:002009-08-05T01:48:16.700-03:00

AboutpHduino is a open hardware and open software for pH measuments using a glass electrode sensor for hydrogen ion and a Arduino board.HistoryJust after I returned from my last post-doc project at San Antonio, Texas, I decided not restart my last project. I did it to finish some works and make an open hardware project in electrochemistry. After some tests, a friend called Denis Vidal, suggested

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com5tag:blogger.com,1999:blog-1033721154498518542.post-65859435399199511192009-08-04T00:22:00.000-03:002009-08-04T01:07:30.162-03:002009-08-04T01:07:30.162-03:00

Hi everybody.I am really happy to announce the launch this project: a pH meter using a Arduino/Freeduino board.PURPOSEConstruct a pH meter using an Arduino/Freeduino board to read pH with a pH glass electrode. It is not a high resolution scientific instrument. This project aims to be simple, using resources from the Arduino, commons and cheap electronic components. The pHduino could be operate

Carloshttp://www.blogger.com/profile/09088461044248860193noreply@blogger.com0