Open Colorimeter Product Guide

This is the documentation site for the Open Colorimeter and new variants including the Multi-Channel Colorimeter, UV Open Colorimeter and Open Colorimeter Plus. Instruments in the Open Colorimeter product line are open hardware science designs with wide-ranging applications. They are standalone, portable instruments which can be used either in the lab, classroom or for measurements out in the field.

Listed below are user guides and tutorials as well as documentation pages for the hardware designs and CircuitPython firmware.

Table of Contents

Introduction

Open Colorimeter Product Line Overview

There are several versions of the Open Colorimeter available. The main differences between them are the light sensor used and it’s positioning in respect to the LED light source. The LED light source is also highly customizable. We have a wide-selection of LED wavelengths in the UV, visible and IR

IO Rodeo BlogJoanne Long

Open Colorimeter Introduction

Colorimeters are extremely flexible and easy to use lab instruments. Below are just some examples of how colorimeters are used: * Water quality testing: there are a wealth of colorimetric assays for measuring water parameters such as water turbidity, chlorine content, pH, water hardness, phosphate…

IO Rodeo BlogJoanne Long

Getting Started: Installing a 3.7V Lithium Ion Battery

The Open Colorimeter can be powered by USB or a 3.7V lithium ion battery. To use the Open Colorimeter without a battery, simply plug in the USB cable for power. However, we recommend using a battery as the instrument works best as a portable device. Currently we are not

IO Rodeo BlogJoanne Long

Getting Started: Basic Operation & Menu Navigation

These instructions below apply to all variants of the Open Colorimeter. The Open Colorimeter has the following features: * On/Off switch: An on-off switch will save battery power when not in use * Micro USB Port: You can power from the Micro USB port and it will also charge up the

IO Rodeo BlogJoanne Long

Open Colorimeter Tests & Tutorials

Open Colorimeter Cuvettes

The Open Colorimeter products ship with a small pack of cuvettes to get you started using the instrument. The type of cuvette included depends on the instrument: * Open Colorimeter & Multichannel Open Colorimeter: Pack of 6 BrandTech macro and semi-micro cuvettes (3 of each) * UV Open Colorimeter: Pack of 4 BrandTech

IO Rodeo BlogJoanne Long

Open Colorimeter Tests

Colorimeters are extremely flexible and easy to use lab instruments. Below are just some examples of how colorimeters are used: * Water quality testing: there are a wealth of colorimetric assays for measuring water parameters such as water turbidity, chlorine content, pH, water hardness, phosphate…

IO Rodeo BlogJoanne Long

Open Colorimeter Tutorials - IO Rodeo Blog

IO Rodeo BlogJoanne Long

Open Source Hardware

3D printed cuvette holder and enclosure

Design methods We have been using FreeCAD for 3D hardware designs as described in this previous Newsletter. In this project we used the KiCad StepUp workbench to import a 3D model of the Sensor and LED PCBs from KiCad and the A2plus Workbench to create an assembly of the complete

IO Rodeo BlogJoanne Long

Open Colorimeter Electronics

Communication with peripheral devices via I2C using 4-wire cables with JST SH connectors, such as Sparkfun Qwiic or Adafruit STEMMA QT, is rapidly becoming a standard on new development boards. This standardized cabling allows multiple sensors to be connected to the development board without any soldering. By using these standardized

IO Rodeo BlogJoanne Long

Open Colorimeter LED Boards

We have designed a series of LED boards which can be used to customize any of the Open Colorimeter products. These include UV LEDs for use with the UV Open Colorimeter, a series of visible and IR LED boards. All of the LED boards are designed with these same features

IO Rodeo BlogIO Rodeo

Light Sensor Boards

As mentioned in the Introduction, the different variants use different light sensor boards. Here we will go into these sensors in more detail. Some similarities we won’t go into deatil but all of these light sensors have the same form factor and standard 4-pin JST SH connectors (also called STEMMA

IO Rodeo BlogJoanne Long

Open Source Firmware

Open Colorimeter CircuitPython Firmware

The Open Colorimeter ships ready-to-use and pre-programmed with firmware, so you do not need to be a programmer to use it! The firmware for the Open Colorimeter is programmed using CircuitPython which is a version of the Python programming language designed to run on microcontrollers. CircuitPython is very easy to

IO Rodeo BlogWilliam Dickson

Installing/upgrading the firmware

In this set of notes we describe how to upgrade or reinstall the firmware on your Open Colorimeter. These instructions can be used whever there is a new firmware release that has new features that you would like to use. There are three steps: * Step One: Download and unzip the

IO Rodeo BlogWilliam Dickson

Customizing configuration and calibration files

The Open Colorimeter ships pre-programmed with the circuitpython firmware. This page describes how to modify the firmware default settings to customize your instrument. Customizing the Open Colorimeter can make it more convenient to use, reduce setup time, help prevent user errors and ensure consist…

IO Rodeo BlogWilliam Dickson

Optimizing the light sensor settings

The Open Colorimeter uses a TSL2591 light sensor, as described in the electronics page. In these notes we describe the light sensor settings and how to adjust them in order to achieve the best results. Open Colorimeter ElectronicsElectronics The Open Colorimeter uses STEMMA QT connectors. Communi…

IO Rodeo BlogWilliam Dickson

Installing/upgrading CircuitPython and the bootloader

As new versions of CircuitPython come out you may want/need to upgrade the version of CircuitPython (or bootloader) running on your Open Colorimeter’s PyBadge. These notes describe how this can be done. Prior to upgrading the bootloader or version of CircuitPython make sure to copy any files you do…

IO Rodeo BlogWilliam Dickson

Calibration Files and Custom Calibration Tools

Overview of Open Colorimeter calibration files

This page gives some more information on the calibrations.json file which is used to load custom calibrations onto the Open Colorimeter. This file contains calibration data for measurements and the individual entries in this file become the tests which are displayed in the Open Colorimeter’s menu. They are displayed

IO Rodeo BlogWilliam Dickson

Creating custom calibrations using oc-cal

In this set of notes we describe how to create custom calibrations for the Open Colorimeter using the command line program oc-cal. This program is part of the open-colorimeter-utils package which is available on PyPi (The Python Package Index). To use oc-cal you will need a working version of Pyt…

IO Rodeo BlogWilliam Dickson

Creating custom calibrations using oc-calibration-app

In this set of notes we describe how to generate custom calibrations for the Open Colorimeter using a simple web app called the oc-calibration-app. This app makes fitting your calibration data and generating the required .json file for your colorimeter quick and easy. The app is developed using the…

IO Rodeo BlogWilliam Dickson

Purchase an Open Colorimeter from the Online Store

Open Colorimeter

The Open Colorimeter is a portable and customizable colorimeter for measuring absorbance, transmittance and concentration. The cuvette holder and enclosure are made from 3D-printed black nylon material and the electronics are programmed with open source firmware written in CircuitPython.

IO RodeoIO Rodeo

Related Links

The Educational Colorimeter Kit (v1.0)

We initially designed the colorimeter as an Educational Kit in 2012 supported by Kickstarter backers. Educational colorimeter kitKit for making a programmable colorimeter for analytical chemistry and biochemistry labs & activities. Arduino compatible.Kickstarter Documentation for the original Educ…

IO Rodeo BlogJoanne Long

Documentation License

Documentation licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).