Interactive control of purpose built analytical instruments with Forth on microcontrollers - A tutorial.

The use of the computer language Forth for controlling experimental analytical instruments built in laboratories is described. Forth runs on a microcontroller and as it is an interpreted language the user can directly communicate with it by employing a terminal emulator program running on a personal computer. Thus the user can test attached hardware, such as pumps, valves, electronic pressure regulators, detectors and chemical sensors, directly from the keyboard. This overcomes the lack of interactivity, a significant shortcoming, of the computer languages C and C++, the default on such microcontroller platforms as the Arduinos, which have become very popular in recent years for laboratory applications. Common examples of purpose built experimental analytical laboratory instruments are sequential injection analysis systems, microfluidic devices, or automated sample extraction systems. Application examples from our laboratory are given, namely the regulation of mass-flow controllers for gases, the sequencing of an experimental capillary electrophoresis instrument and the acquisition of a signal from an alcohol sensor.