首先研究CAN總線和SAE J1939協(xié)議，提出一種基于MC9S12HZ256微控制器的總線式汽車數(shù)字儀表解決方案。詳細(xì)介紹SAE J1939協(xié)議的報(bào)文幀格式及應(yīng)用層協(xié)議中發(fā)動機(jī)相關(guān)參數(shù)的定義，以及步進(jìn)電機(jī)及其驅(qū)動和車速信號的處理方法。該數(shù)字儀表系統(tǒng)硬件平臺由微處理器和信號采集和信息處理及顯示等模塊組成。軟件設(shè)計(jì)部分編程實(shí)現(xiàn)了對CAN總線和各傳感器數(shù)據(jù)的讀取、處理。該系統(tǒng)能夠?qū)崟r(shí)反映車輛工況。
Abstract:
In this paper，CAN bus and SAE J1939protocol are researched，and a vehicle digital instrument solution based on MC9S12HZ256MCU is proposed.The message frame format and some engine-related parameters’definition in SAE J1939application layer protocol are introduced in detail.Stepper motor and its driver，the methods of speed signal process-ing are also introduced.The hardware platform of vehicle digital instrument is composed by MCU，signal acquisition mod-ule，and signal processing and displaying module.Data receiving and processing from CAN bus and sensors are accom-plished by programming，and vehicle condition can be reflected in real-time.
