Wednesday, April 27, 2011
ELM327 : Cheapest CANBUS Interface
I have discovered both DOS and Win32 code to support the two most popular and ubiquitous interfaces to CANBUS for both serial ports and USB, the SJA-1000 chip for PCI & PC/104, the ELM327 interface for USB and Serial ports.
I picked up an SJA-1000 controller board for $12.00 on EBay, I got an ELM327 interface for $11.00 with free shipping. Once you have these boxes to connect your CANBUS (ECU) line to your PC through this interface, you can read and write as freely as you do to any other control device in Vault-OS.
I know how to build an I2C interface for under $5.00 for both serial and USB ports. The CANBUS will require you to obtain either the SJA-1000 board or else the ELM327 box. Once you have your CANBUS talking by either means, you can now speak to every single CANBUS ECU in the world on this line. The average automobile has around 70+ of these ECUs on them, in a post-apocalyptic environment there should be no shortage of car hulks you can harvest if you need to.
Considering I now have the start of a generic RS-485 interface in Lua script with the capacity to transmit Modbus protocol over this line if desired, I'd say this should just about cover any type of industrial device you can imagine you might want to hook up to Vault-OS right through to the end of next century.
To those of you who have frequently urged me in emails to seek another paradigm than I2C alone, thanks for constantly prodding me. It only took a couple years and I realized the wisdom of the idea. I can't imagine version 1.0 of VAULT-OS without CANBUS now.
UPDATE: Purchase CANBUS experimenter's node from Futurlec to get your system up and running on plain vanilla PELICAN protocol as quickly as possible!
(Note that a single CAN Node like the one above is nearly sufficient by itself to run a microgarden hydroponics setup through a web server system like VOS, with four digital and two analog connections.)