This is an Arduino library to emulate Alpines M-Bus which is used on a variety of car radios. You can send and receive messages as well as send special messages which trick the radio in believing it communicates with an cd changer.
Electrically, you'd want to have a piece of circuitry to split the send and receive line which is shown here(not my website): http://www.hohensohn.info/mbus/index.htm I also used this site for reference on the bus itself.
Copyright 2012 Oliver Mueller
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.