Esp32 (IX): OTA function of function development

1、 Upgrade strategy

    Face before Bootloader In the analysis of , We know ESP32 Of OTA The upgrade is basically reliable , Reliable means that even if the upgrade fails , write in IMAGE Incomplete , The equipment can still be used .

     about OTA upgrade , What impressed everyone was Android Mobile phone upgrade ,Android The upgrade of mobile phones is indeed quite complete and robust , about IOT For equipment , There is no difference Image The mechanism of , So as long as it is simple and effective .

     Later, we determined that the background silent forced upgrade , After the device is connected to the Internet , Only check that there is a new version , Will be forced to upgrade in the background , It is insensitive to users .

     Then there will be another problem , Usually, the interaction between such devices and users is very limited , There is no interface , There is no such complicated operation as button sound , How to know what version of a device is , Is the device upgrade successful ？ Our solution is to record on the server side .

    1、 Start at a device HTTP Make a note when downloading , Then you know that a device has downloaded that version ;

    2、 At the same time, in the request to check the new version , Bring the current version number , The server remembers the device MAC Address and current version , Then we know which versions have been upgraded successfully , At the same time, we also know which devices in the latest version have been upgraded successfully .

    OK, Experiments show that the overall strategy is simple and effective ！ I wrote it briefly , You can also discuss .

    

2、 Version comparison

In order to save resources , You can restart the system every time , And after successful networking , Check for new versions .

3、 Download and upgrade

It's easier to download , Build your own server , At present, various cloud hosting services are also very convenient .

Upgrade write file ESP32 Have some of your own API, It can help us simplify some logic .

https://esp-idf.readthedocs.io/en/latest/api-reference/system/ota.html?highlight=ota