Including a battery gauge to a Citroën C-Zero electrical automotive

The Citroën C-Zero is an electrical metropolis card bought within the European market. It’s a rebadged Mitsubishi i-MiEV, which is predicated on the Mitsubishi i kei automotive platform. Kei automobiles, in Japan, are a particular class that obtain authorities and insurance coverage advantages for being so small. In consequence, the C-Zero is tiny and low-cost, in contrast to the Tesla electrical automobiles which can be so standard within the US. A technique that Citroën reduce corners was by omitting infotainment and sprint screens, which suggests there isn’t any means for drivers to see detailed knowledge on their battery standing. Pierre Muth needed that info and so he used an Arduino so as to add a brand new battery gauge to his Citroën C-Zero.

The Citroën C-Zero could not present drivers detailed battery info, however the automotive’s pc does have that knowledge. As with the automotive’s varied sensor readings, statuses, and instructions, that knowledge flows by means of the CAN (controller space community) bus.Nonetheless, Citroën (like most automakers) makes use of a proprietary protocol for his or her CAN bus and doesn’t publish its specifics. Customers can entry the CAN bus, however can’t learn or inject messages with out understanding the protocol. Luckily for Muth, fans of the C-Zero/i-MiEV reverse engineered the CAN bus protocol and posted the main points on-line.

With that info, Muth was in a position to entry the CAN bus with an Arduino Micro board and a CAN bus protect primarily based on an MCP2515 CAN transceiver. That allow him pull the information on the real-time battery output, voltages of the C-Zero’s 80 battery cells, and the general cost share. Muth displayed that info on an OLED display inside a pleasant 3D-printed gauge pod enclosure that he mounted to his sprint. With lower than $75 value of {hardware}, Muth was in a position so as to add a standing show that Citroën couldn’t discover room of their price range to implement.