Contributed by Shenye, organized by Ai-Thinker

Simple Analysis of Ai-WB2 Flash Programming

#1 DCD:1 CTS:1 RI:0

1. DCD (Data Carrier Detect): 1
   • Indicates that the modem (or other device) has detected the carrier signal from the remote end (i.e., the connection has been established).
   • 1 (high level/active) = carrier detected (connected).
   • 0 (low level/inactive) = no carrier detected (not connected).
2. CTS (Clear To Send): 1
   • Indicates that the device is ready to receive data (a hardware flow control signal).
   • 1 (high level/active) = ready to receive data.
   • 0 (low level/inactive) = not ready (pause transmission).
3. RI (Ring Indicator): 0
   • Indicates an incoming call (commonly used for modems).
   • 1 (high level/active) = ring detected (incoming call).
   • 0 (low level/inactive) = no ring (no incoming call).

** DCD:1 CTS:1 RI:0 Status Interpretation **:

• Connection established (DCD is high).

• The device is ready to receive data (CTS is high).

• No incoming call/ring signal (RI is low).

  Communication Process

  

• Send an uppercase U; the check will return an ok. Do not send it repeatedly — the maximum interval is three seconds.

• Based on this, you can determine whether the microcontroller is ready for downloading, and then download.