15001. System design scheme

1 System log scheme

1.1 background

In order to better control the products after mass production , Conduct product use scenarios 、 Life cycle 、 Troubleshooting 、 Return to the factory for maintenance and big data analysis , We need to build a system log system for our own products .

1.2 Product needs

According to different system requirements , Define what needs to be recorded in the system log .

system log	Log description	Log format	Allocate space	remarks
The total running time of the system	The whole life cycle	Hours + minute	–	Record the working hours of products in the whole life cycle , Analyze the service life of the product under different scenarios in combination with temperature
Power on times of the system	The whole life cycle	frequency	–	Record the power on times of the product in the whole life cycle
On off event	The whole life cycle	frequency	–	Record the time of the event
Temperature of key components	The whole life cycle	Record according to the temperature gear :[-40, 0), [0, 20), [20, 50),[50, 85]	–	By analyzing the temperature of key components , Analyze the influence of temperature on the service life of products
Statistics of external operation instructions	Record recent xx Article can be	–	–	During product operation , Generate any exceptions , Through backtracking instructions , Get the running status of the product at that time
The system prints logs	Key parameters print after startup , Turn it on LOGO, frequency , Time	–	–	product bug Debugging is convenient for positioning

1.3 Implementation scheme

Storage location	Advantages and disadvantages	Failure risk	Solution	remarks
DDR	The space is large 、 Fast reading and writing	Power loss	–	–
Flash	The space is large 、 Fast reading and writing 、 Don't lose power 、 Erasure life 10w Level	Risk of power loss when writing or erasing	The hardware slows down , Dual backup storage , Cross write	–
eeprom	Small space 、 Fast reading and writing 、 Don't lose power 、 Erasure life is millions of levels	Risk of power failure when writing	Backup battery slow down ; use ADC To detect the operation when the power down voltage is lower than a certain value EEPROM; use CMP+ and CMP- To compare voltage interruptions , Then operate EEPROM.	–

In the absence of hardware as an auxiliary power down solution , This power failure problem cannot be completely solved from the perspective of software , use flash Cross backup write comparison , It can reduce the risk value of power failure when erasing .

1.4 Technology path

1.zlog The log comes with month, day, hour, minute and second https://blog.csdn.net/weixin_28673511/article/details/123116145
2.syslog The system has its own log system Month day hour minute second