LeoPhi USB pH interface

The Leonardo pH Interface is an Arduino compatible USB pH interface created to make pH monitoring and/or controlling projects as simple as possible. Able to communicate over many protocols (USB,I2C, SPI, Serial, 1Wire) its the perfect unit to add into any project that requires pH logging or control! The Manual contains usage information as well as specifications and pins outs. This is an open source hardware project and all files can be found on LeoPhi's Project page!

Reading pH just got a bit easier

With Arduino 1.0.2 and up how the Leonardo reset was changed and with the popularity of the LeoPhi platform I thought it would be a good idea to update the hardware and bring the bootloader up to the newest version.

As before reading pH has never been easier, and with the new hardware version so it augmenting LeoPhi! All Standard Leonardo pins are brought out via the Digital Header and Analog header!

Simply plug in LeoPhi via a USB port, point you favorite Serial Port monitor to LeoPhis port and off you go! LeoPhi even works on openWRT flashed routers for pH readings over Wifi!

Please see LeoPhi's Project page for more information!

Basic Usage

Usage of LeoPhi is very easy, with on board USB a fully CDC compabtible bootloader (modified leonardo) all you need to do is plug it in and send some serial commands! Send an S to calibrate to ph 7 solution, F to calibrate to 4 an R to read and etc...

There are 2 serial ports one for the USB and one is the hardware serial port(Tx,Rx), this makes it useful as a USB to serial converter as well, but also means that the proper port must be select for use in any project. For example a Raspberry pie could interface LeoPhi(carefull on levels) over USB serial while the same data is dumped over the Hardware Serial to another Arduino. An I2C slave example code is also implemented which uses some of the same commands and shows how to easily implement a pH sensor with an I2C interface!

Some of the commands are:

• C : Continuous Read Mode: Dump readings and data every second
• R : Single pH reading: response "pH: XX.XX" where XX.XX is the pH
• E : Exit continuous read mode
• S : set pH7 Calibration point
• F : set pH4 Calibration point: also recalcs probe slope and saves settings to EEPROM
• T : set pH10 Calibration point: also recalcs probe slope and saves settings to EEPROM
• X : restore settings to default and ideal probe conditions