HC-12 T Commands

AT Command Purpose Example HC-12 Response Notes
AT Check comms AT OK
AT+Bxxxx Set Baud rate AT+B9600 OK+B9600 The baud rate can be 1200bps, 2400bps, 4800bps, 9600bps, 19200bps, 38400bps, 57600bps, or 115200bps. The default is 9600bps.
AT+Cxxx Set channel number AT+C012 OK+C012 Channel numbers are from 001 to 127 although over 100 the performance can't be guaranteed. The working frequencies start at 433.4MHz and go in 400KHz steps thus channel 100 is at 473.0MHz. When a particular channel is used a gap of five channels should be left on adjacent systems to avoid interference and desensitization.
AT+FUx Set transmission mode AT+FU3 OK+FU3
AT+Px Set transmission power AT+P3 OK+P3 Transmission power (x) can be set to 1 to 8 representing powers from -1dBm (0.8mW) to 20dBm (100mW) in 3dBm steps. The default setting is 8, 20dBm (100mW).
AT+Ry Request a current setting AT+RB OK+B9600 Request the currently set status of the module. AT+RY returns the baud rate, AT+RC returns the channel number, AT_RF returns the transmission mode, and AT+RP return the transmission power.
AT+RX Request all current settings AT+RX OK+FU3 OK+B9600 OK+C001 OK+RP:+20dBm All the current settings are returned togther
AT+Udps Set data format AT+U801 OK+U801 This sets the number of data bits (d), the parity (N = none, O = odd, and E = even), and stop bits (1 = one stop bit, 2 = two stop bits, and 3 = 1.5 stop bits).
AT+V Request the module's current firmware version AT+V OK+HC-12_v2.3
AT+SLEEP Enter sleep mode AT+SLEEP OK+SLEEP Enter sleep mode on exiting command mode. Power cycling wakes the module up again
AT+DEFAULT Sets default values for all parameters AT+DEFAULT OK_DEFAULT This sets the module to 9600bps, 8 data bits, no parity, 1 stop bit, channel 001, and transmission mode FU3.
AT+UPDATE Prepare for new firmware Puts the module into update mode waiting for new firmware. Power cycle to return to normal operation.

All commands must be sent at 9600bps, 8n1 mode regardless of any transmission settings.