AT default commands can be saved into flash to initialize the systems, such as customer Mac address, UART Speed, auto connect to join a network once the SSID and password have been saved into “User Space”…
We architected the flash memory to have two banks of flash, partitioned as :
1. Factory Default Space
2. Customer “User Space
We recommend that customers save there default settings in “User Space” and if you have trouble with flash in the field or a flash error, you can switch to “Factory space” and do a reset , this will erase the flash in the “User Space” , this starting the module in a known state.
The AT command “Z3” selects the flash partition to save your settings, for example Z3=1, the user space will be selected to save your parameters.
Once you selected the flash partition you can enter your preferred default configuration/ settings and then enter the AT command “Z1” to save the parameters. Upon your next boot, the module will automatically use those settings.
Here is a simple example:
U2=19200 (This sets the UART baud rate to 19,200, while the current default is 56K)
Z1 ( This will save the baud rate to 19200 into User Space (User Space is the default)
One thing to keep in mind, is if in the future you do Firmware update via UART,JTAG or over the air you may want to perform the AT command “Z2” to clear any saved settings