Trip computer

The first, mechanical trip computers, such as the Halda Speedpilot, produced by a Swedish taximeter manufacturer, were made in the 1950s as car accessories to enable the driver to maintain a given time schedule, particularly useful in rallying.

The most advanced trip computers are reserved for high-end cars and often display average calculations for two drivers, a stop watch, tire-pressure information, over-speed warnings, and many other features.

GM and FCA vehicles provide oil change alerts based on the number and length of trips, engine temperature, and other factors.

In 2004, Linear Logic developed the ScanGauge, which at the time was the only easily installed (via OBDII) accessory that worked as a trip computer, 4 simultaneous digital gauges, and a diagnostic trouble-code reader.

In 2008, the OBDuino project announced[4] a low-cost DIY trip computer design using the OBDII interface and the Arduino hobbyist microcontroller platform, released under the GPL open source license.

A Halda Tripmaster is mounted under the dash of this Saab GT850 .
The trip computer's display in a 2004 Acura TL , tracking the average mileage, average speed, and distance traveled for the stated time period.
Trip computer display