1.Module with USB Micro interface, Can use the computer USB power supply.
2. Module corresponding port,it’s marked on the PCB board, - + respectively connected with negative electrode and positive electrode of power supply (battery).Suggested that use the battery or other regulated power supply as the power supply. Switching power supply without filter is not recommended , such as Mobile phone charger, Mobile power supply and other switching power supply. Otherwise, the normal operation of the module will be affected by the interference of the power supply. This module works properly Voltage is 3.0-5.0V. Note that the power supply voltage should not exceed this range.
Antenna
FM_ANT port used to connect FM antenna, Recommended external pull rod antenna with length 75cm In order to better receive the FM signal.
Earphone / speaker output
This module comes with 3WX2 channel audio amplifier, connect speaker port if required, proposed to using 4 /3W speakers. Audio automatically switches to headphone channel when the headset is plugged in, speaker channel auto shutdown at the same time.
Volume adjust
Turn VOL encoder to adjust the volume, LCD screen display volume series at the same time.
Frequency regulation
Turn FRE encoder to adjust the launch frequency, LCD screen displays the current frequency at the same time.
Auto search
Short press FRE encoder, local radio stations are automatically searched until the search to a valid radio, LCD screen displays the current frequency at the same time.
Mute
Down short press VOL knob to switch mute or un-mute.
Automatic squelch switch
Down long press VOL knob switch mode for open or close automatic squelch function. Open automatic squelch when the LCD display ON, close automatic squelch when the LCD display OFF.
Automatic squelch threshold adjustment(Must auto squelch switch is open is effective)
Down long press FRE knob to enter the automatic squelch threshold adjustment interface, Rotary VOL knob to adjust the action of automatic squelch threshold, adjusting range is 0-31. The higher the value, the higher the threshold, weak signal is more likely to be muted. The lower the value, the lower the threshold. Signal too Strong, the more difficult to be mute.
Serial port(No need to connect if without serial port control)
Module reservation TTL level serial port control interface, TTL serial port and the module communication need to connect the module of the UART_TX, UART_RX and GND, it is marked on the corresponding position of PCB. Can use external MCU or computer serial port to send command control module.
Serial port instruction consult FM receive AT instruction list.
Baud rate: 9600 TTL level
Instruction Name
instruction Example
Instruction Description
Ranges
return value
Connection Test
AT
OK
Set the current frequency
AT+FREQ=875
87.5MHZ
760-1080
Frequency
Or ERROR (error)
frequency -0.1MHZ
AT+FREQDEC
The current frequency
frequency +0.1MHZ
AT+FREQADD
The current frequency
Up automatic search radio stations
AT+SEEKUP
The first search frequency
Downward automatic search radio stations
AT+SEEKDOWN
The first search frequency
Play pause / resume play
AT+PAUSE
PLAY(Play) PAUS(stop) ERROR
set volume
AT+VOL=8
Set current volume 8
00-15
VOL Value or ERROR
volume
AT+VOLDEC
volume -1
VOL Value or ERROR
volume +
AT+VOLADD
volume +1
VOL Value or ERROR
Mute
AT+MUTE=YES
Mute
OK or ERROR
Cancel Mute
AT+MUTE=NO
Cancel Mute
OK or ERROR
Set the backlight off time (in seconds). Where 00 is off
01 long bright
AT+BKLT=10
Setting the backlight off 10 seconds delay
00-59
BKLT Value or ERR
Restore factory settings
AT+RESET
Restore factory settings:
VOL=30 // volume 16
FRE=875 // frequency 87.5MHZ
BANK=20// Backlight delay 20s Extinguish
CAMPOS_OFF // Off campus radio FRE=875 // 875MHZ
RESET OK
Returns current status information module
AT+STATUS=?
VOL=16 // volume 16
FRE=875 // 87.5MHZ
PLAY/PAUS// Muted BANK_OFF(BANK_ON)// CAMPOS_OFF(CAMPOS_ON)// Open campus radio