CAN Bus Communications Decoded: Step 1: Plan Your Network
Step 1: Plan Your Network
02.08
00:00 | - In this worked example, we're going to look at setting up a CAN network from scratch to transmit some data around a racecar. |
00:07 | Now the fabricator here at HPA, Jimmy, is building an Audi B5 racecar and we've got some of the electronic package that he's going to want to put into that car. |
00:15 | So we're going to get everything fired up on the bench here and make sure we can get the data flowing around the network to and from the devices that we need to. |
00:25 | Now a bit of detail on the bench setup I've got here, I've got our 12 volt power supply out to my CAN bridge device, we've got an AiM MXP dash, we've got a Plex micro dash and then we've got our Link G4 Fury ECU. |
00:41 | So these are all just being powered from our CAN bridge here and that's hooking all the CAN bus high and low pins to one another as well. |
00:50 | Now I've read the documentation pretty thoroughly for all these devices and I've determined how they're going to have to be laid out on the bus to obey our bus wiring rules. |
01:00 | The Link G4+ Fury ECUs have a built in 120 ohm termination resistor that is actually soldered onto the board so it can't be removed. |
01:09 | So that's going to have to be one of the ends of our trunk. |
01:13 | The AiM dash, you can actually select whether you want the resistor enabled or not so that is excellent, we've got options there and the Plex micro display also has a termination resistor hard wired onto the circuit board on there. |
01:28 | So that's going to have to be the other end of our trunk and our AiM dash is going to have to be on a node. |
01:34 | Now the planning for the harness in the vehicle, this isn't going to cause us any major issues. |
01:37 | Because the AiM dash here is going to be a driver display with general purpose warnings and alarms and the Plex display here is going to be a nice bold gear position display. |
01:49 | So they're going to be in quite close proximity to one another so the bus wiring is actually going to be pretty easy to have, the main trunk go from the Link G4 ECU up to the dash area and split off to a node for our AiM dash. |