On 10/05/2014 11:37 AM, Michael Ross via EV wrote:
Automotive CPU, MPU, ECU, etc. are often designed using in ASICs (Application Specific Integrated Circuits) and nowadays FPGAs (Field Gate Programmable Arrays). The software is not served up by a drive, or kept on a flashable EEPROM, it is literally built into the silicon.
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It may require the original the development system to reprogram it. Or it can only be reprogrammed by replacing chips and boards - meaning it is very unlikely a DIYer will have the ability to hack it.
That's exactly what "chipping" an ICE does. Replaces or reprograms a memory chip that contains data tables used by the car's software. It's a relatively safe process as you can only screw up the ICE's power profile and emissions output but can't cause the onboard computer (and maybe the car) to crash.
The only viable open source solution would be to design a carputer that can read the car's original sensors, process the data, and use that to control the fuel injection, dash, door locks, etc. In the case of a Tesla, it might run the charger/inverter. Unfortunately, most EV-specific hardware probably has its own computer system that expects to send/receive proprietary and possibly encrypted data - making it close to impossible to control with a DIY computer unless MUCH help and documentation is provided by the OEM.
Related story: A friend of mine converted a 2000-ish VW Jetta using a series DC motor. His biggest headache was the low oil pressure buzzer in the instrument cluster. Without a valid reading, the buzzer would go off constantly. He cooked up a circuit that would send a "normal" oil pressure reading, then proceeded to get startled at every stoplight! The dash computer would see the motor RPM drop to 0, notice the oil pressure was still normal... and set the buzzer off! Don't know if he ever managed to trick the instrument cluster into staying quiet. Didn't want to kill the buzzer as it is also used as a headlight reminder, seatbelt warning, etc.
-Adrian _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
