From 4c3b9ed9f52a47c853125f848fab50ad7ff11f3b Mon Sep 17 00:00:00 2001 From: norly Date: Fri, 4 Mar 2022 08:06:36 +0100 Subject: [PATCH] readme.rst: Add hint on upping the interface before use Also name 500kbit/s as the most common OBD-II speed, to save newcomers some headache. --- readme.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/readme.rst b/readme.rst index 4103d18..e379221 100644 --- a/readme.rst +++ b/readme.rst @@ -105,6 +105,20 @@ The line discipline can be attached on a command prompt as follows:: To change the ELM327's serial settings, please refer to its data sheet. This needs to be done before attaching the line discipline. +Once the ldisc is attached, the CAN interface starts out unconfigured. +Set the speed before starting it: + + # The interface needs to be down to change parameters + sudo ip link set can0 down + sudo ip link set can0 type can bitrate 500000 + sudo ip link set can0 up + +500000 bit/s is a common rate for OBD-II diagnostics. +If you're connecting straight to a car's OBD port, this is the speed +that most cars (but not all!) expect. + +After this, you can set out as usual with candump, cansniffer, etc. + Known limitations of the controller -- 2.30.2