Typically, the best solution to improve a tool is by changing every thing! This precept was utilized when Brian Benchoff gave a digital improve to a Eighties Comuta-Automobile’s gauge cluster.
“How I used Two Million transistors to exchange 4 relays.”
Benchoff’s long-term undertaking is modernizing a Comuta-Automobile whereas protecting the Eighties nerd aesthetic. These electrical cars featured lead-acid batteries powering a (as much as) six-horsepower DC motor. You may additionally acknowledge these vehicles as their predecessor, the Citicar.
Comuta-Automobile 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.
Thankfully, the trendy motor controller supplies velocity info by way of the CAN-bus. Virtually all trendy cars talk with gadgets by way of the CAN bus. So, with a handful of microcontrollers and CAN PHYs, this Comuta-Automobile acquired a big digital improve inside and outside.
A 1/8-inch thick aluminum plate held the unique gauge cluster elements. The brand new steel plate is twice as thick as the unique and comprises a dense LED matrix, a key swap (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 automobile’s velocity, turning the show right into a speedometer and odometer. Because the battery administration system is on the CAN bus, this show may present the Lithium battery’s state-of-charge and estimate the automobile’s vary.
Drive, Impartial, and Reverse make up the gear alternatives. A custom-made rotary knob with a 16-segment LED indicator at its heart supplies this interface. Benchoff says the satisfying facet of this association is that the segmented LED stays put whereas the knob’s exterior ring strikes.
MOSFETs, Screw Terminals, and Deutsch CAN Connectors (📷: bbenchoff)
4 switches on the opposite aspect allow the lights, windscreen wiper, defroster, and hazard flasher. Within the authentic electrical system, the switches enabled a relay. The upgraded design includes a MOSFET with a shield-like secondary card that attaches every system 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.
Beneath these switches is a alternative panel for the previous local weather controls. The improve solely includes a 150-watt moveable 12-volt heater for defrosting the home windows. This accent solely wants a single swap. So, the alternative for the local weather panel is usually empty. This aesthetic reminds us of comparable “blanks” present in manufacturing cars the place optionally available options are lacking. (Though none of these vehicles have a Social gathering choice, like this one!)
Prime: Unique Panel, Backside: Substitute (📷: bbenchoff)
A maple burl veneer covers all the digital gauge cluster and completes the look. You may study extra about Benchoff’s Comuta-Automobile Restoration undertaking on this web page. All design recordsdata are out there right here if you wish to replicate this one-of-a-kind dashboard, together with Social gathering swap.
