Typically, the simplest approach to improve a tool is by changing every part! This precept was utilized when Brian Benchoff gave a digital improve to a Eighties Comuta-Automotive’s gauge cluster.
“How I used Two Million transistors to interchange 4 relays.”
Benchoff’s long-term undertaking is modernizing a Comuta-Automotive whereas preserving the Eighties nerd aesthetic. These electrical vehicles featured lead-acid batteries powering a (as much as) six-horsepower DC motor. You may also acknowledge these automobiles as their predecessor, the Citicar.
Comuta-Automotive Pre-Acqusition, U-Haul for Scale (and towing). (📷: bbenchoff)
An early improve Benchoff made was changing the electrical drive with an AC induction motor and a contemporary velocity controller. Sadly, this variation meant the inventory speedometer was not usable because it makes use of a cable linked to the unique motor shaft. Benchoff wanted one other resolution for this essential meter to maintain the upgraded automotive street-legal.
Fortuitously, the trendy motor controller gives velocity data by way of the CAN-bus. Nearly all fashionable vehicles talk with units by way of the CAN bus. So, with a handful of microcontrollers and CAN PHYs, this Comuta-Automotive obtained a major digital improve inside and outside.
A 1/8-inch thick aluminum plate held the unique gauge cluster parts. The brand new metallic plate is twice as thick as the unique and comprises a dense LED matrix, a key change (ignition), a custom-made rotary knob for choosing the gear, and 4 accent switches.
LED Odometer and Rotary Transmission (📷: bbenchoff)
The centerpiece show comprises 702 LEDs configured in an 18 x 39 matrix pushed by an IS31FL3741 IC. An Adafruit Feather M4 CAN Categorical interfaces with the CAN bus to obtain details about the car’s velocity, turning the show right into a speedometer and odometer. For the reason that battery administration system is on the CAN bus, this show may also present the Lithium battery’s state-of-charge and estimate the car’s vary.
Drive, Impartial, and Reverse make up the gear choices. A custom-made rotary knob with a 16-segment LED indicator at its heart gives this interface. Benchoff says the satisfying facet of this association is that the segmented LED stays put whereas the knob’s outdoors ring strikes.
MOSFETs, Screw Terminals, and Deutsch CAN Connectors (📷: bbenchoff)
4 switches on the opposite facet allow the lights, windscreen wiper, defroster, and hazard flasher. Within the unique electrical system, the switches enabled a relay. The upgraded design contains a MOSFET with a shield-like secondary card that attaches every gadget with screw terminals. An ATmega328p, the identical processor discovered within the Arduino Nano, controls the MOSFETs and communicates with the CAN bus by way of a Microchip MCP2515 CAN Controller and MCP2551 CAN Transceiver.
Under these switches is a alternative panel for the previous local weather controls. The improve solely contains a 150-watt moveable 12-volt heater for defrosting the home windows. This accent solely wants a single change. So, the alternative for the local weather panel is generally empty. This aesthetic reminds us of comparable “blanks” present in manufacturing vehicles the place non-compulsory options are lacking. (Though none of these automobiles have a Celebration possibility, like this one!)
Prime: Authentic Panel, Backside: Alternative (📷: bbenchoff)
A maple burl veneer covers your entire digital gauge cluster and completes the look. You may study extra about Benchoff’s Comuta-Automotive Restoration undertaking on this web page. All design recordsdata are obtainable right here if you wish to replicate this one-of-a-kind dashboard, together with Celebration change.