USR-DR404 user manual
Jinan USR IOT Technology Limited
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Diagram 21 Set serial port parameters on web page
AT command:
If the user needs to modify the baud rate of the DR404 to 115200bps, as follows:
AT+UART= 115200,8,1,None,NFC
3.3.2. UART Free framing
Take sent data from serial device to the DR404 as an example to show the steps of the free framing: if n is the free
frame interval, unit is ms, when T1 >n, T2<n, T3<n, T4<n, T5<n and T6>n, then take byte1 -byte5 as a frame, as bellow:
Diagram22 Switching command mode order
Default interval between 2 bytes is 10ms, that means if the time more than 10ms, this frame will be over.
And interval can change into 50ms to meet the custom’s requirement, setting command are as fellows:
AT+FUARTTE=normal
After setting, restore to the factory default value will enable it.
AT+RELD
Note: AT+RELD can not restore the above setting.
After testing, if the interval set to be 10 ms, and small amount of data, the delay time of the loopback from WIFI
->UART->WIFI is about 40~50ms.
But ,if the interval is 10ms and the MCU can not confer to send the next bytes in 10ms, and the serial data might be
breaking.
