| With the wide application of electronic information technology in agriculture, agricultural machineryoperation precision has been improved, but at the same time, defects caused by the increase of the electroniccontrol unit also emerged, such as increased volume, strong disturbance. In order to solve this problem, somecountries apply the controller area network（controller area network, CAN）multi-master bus, to variouselectronic control units connected to agricultural machinery, completing the information transmissionefficiency. Thereby greatly simplify the wiring harness, reduce the interference, but also improve the accuracyof real-time information transmission.Precision seeding machine as a kind of agricultural machinery, also exists the problem of monitoringinformation transmission not timely when in the monitoring process of sowing the seeds, in order to adapt tothe international agricultural development, this paper introduces a kind of seeding monitoring system,whichcore communication technologies based on CAN bus technology. The sowing sensor collect data informationin the field fist, then the intelligent CAN node processes it, broadcasts to the entire CAN bus network, andmake information message, with the only ID message for identifier, transfers to the monitoring system whichestablished in the monitoring of the master node. The master node carries on analysis the received messagesand other processing, and eventually make the actual situation of sowing display on the monitor interface inreal-time and accurately. The driver can see the sowing directly from the monitor main terminal node（instrument panel） in the operating room.This paper takes CAN as the core to discuss and study its key technology, including technicalspecification, characteristics, communication protocol, and based on this analysis, detailedly research andanalyze the agricultural standard ISO11783, finally design the communication protocol of the system.SelectCAN controller and driver according to the communication protocol designed. This paper presents thehardware and program design of platform. The hardware circuit board drawing of seeding monitoring sensorCAN intelligent node is drawn in Altium Designer Summer09, the intelligent node function program isprogrammed in keil software by C language, and make the*.hex file; The monitoring master node is consitedof CAN232adapter and embedded touch one machine as the hardware platform, its monitoring systeminterface design and monitoring function is programmed in the Windows CE environment by C#.net language.At the same time, after the completion of the test system design, debug, we conduct the bench experiment ofthe seeding monitoring using the platform, and verified the feasibility of the platform design and the accuracyof communication protocol. |
