I. Project design background and overview
Sound is one of the most important forms of information transmission. In different environments and different spaces, we have different and even demanding requirements for the transmission and reception of sound. In view of this, our team designed and produced a multi-function voice wireless transmission system based on FM, which can realize wireless transmission and reception of voice.
This product features the following two features:
a. Campus/station radio broadcast.
b, car phone hands-free receiver.
Mainly solve the following two major difficulties:
a. The existing campus/station wireless broadcasting transmission frequency is fixed single, easy to cross-frequency, and the channel is easy to be polluted; the existing campus/station cable broadcasting route has high cost and cannot meet the requirements of large-scale colleges and universities. It will inevitably lead to the weakening of the signal and the increase of the failure rate, so that the maintenance cost will rise sharply.
b. There is a certain danger in the manual answering of the phone. This product can free your hands and let you answer the phone without leaving the steering wheel to protect your safety.
Second, the project design principle
1, an overview of the principle
This product is a voice transceiver system based on the FM transceiver chip RDA5820. The chip RDA5820 is connected to the single chip microcomputer by the led IIC interface as a control terminal. The MCU writes the RDA5820 register through IIC to control the following functions: FM transmit/receive switching, accent boost, soft mute, soft squelch, frequency setting, transmit power adjustment, sensitivity adjustment, etc.
a. For campus/station wireless broadcasting function, this product can receive FM broadcast in the frequency range of 56~115Mhz, or freely select the frequency band in the free frequency band of 65~115Mhz for other sub-devices to receive, forming a broadcast information network.
b. When using the hands-free answering device function of the car phone, when the call is detected, you only need to press the button on the microphone to realize the phone connection. The incoming call voice and the user voice can be released by the FM in the car audio. You can talk to the microphone only, no matter where the phone is placed in the car, you can achieve a good call.
2, the hardware design principle
The system is divided into voice transceiver module, keyboard input module, LED digital tube display module, power module, buzzer prompt module, and single chip processing module.
Voice transceiver module: responsible for broadcast reception in the transmit and receive modes of input audio in transmit mode.
The MCU processing module: in response to the input command, controls the operation of the voice transceiver module through the IIC interface.
Digital tube display module: displays the current frequency band or fault code.
Keyboard input module: user command input, a total of 4 keys: can achieve transceiver switching, power adjustment, frequency band selection, automatic search and other functions.
Beep prompt module: The button presses the sound, and a major error occurs.
Power module: Provide 5V and 3.3V voltage to supply MCU and transmit and receive modules respectively.
3, software design principles
Software development is done under keil4. The project file consists of .c and .h files. .c file
For main.c fm.c rda5820.c, each .c file is assigned a .h file with the same name.
Software operation, first initialize the system, start IIC, start working. This product works in two major modes - send and receive, through the working mode flag WorkMode_Flag with the while (! WorkMode_Flag) function and while (WorkMode_Flag) function to switch. The change of WorkMode_Flag is done in a sub-mode in a sub-mode based on keyboard input. In each sub-mode, the MCU reads and writes the RDA5820's registers through the IIC interface to control it. If the CHIP_FUNC[3:0]=0 of the 40H register is set, the current working mode is set to FM receiving mode, the BAND[3:2]=00 setting 03H register is defined as the working frequency band is 87-108Mhz, and the BASS of the 01H register is set. ]=1 Turn on the bass boost.
In the sending mode, the mobile phone connection and the detection of the incoming call are also performed, and the mobile phone incoming call opens the hands-free answering device function.
Electric Mop
Zhengzhou Banghao Electronic is Auto Floor Cleaner facotry, more than 10 year poduce and export experience,best quality Electric Moped For Adults cheap price cexport to more than 20 country. best Floor Mop Clean Machine. Cordless Floor Clean Machine with water tank, auto floor cleaner Steamer Mop Vacuum . china best mop clean machine, best Electric Mops and Scrubbers, Electric Spin Mop, Cordless Floor Clean Machine suit in home,office and hotel. Electronic Mop Clean Mchine 18w,voltage 74v, battaery 2000MA, Carpet Steam Cleaner noise less than 60db. Steamer Mop Walmart is very popular. Change,start with owning high-end smart mopping machine. Hoover Steam Mop double wheel sponning mop,no bending,not arduos,easy to mop.
Electric Mop
Electric Moped For Adults,Steamer Mop Vacuum,Steamer Mop Walmart,Carpet Steam Cleaner,Hoover Steam Mop,Electric Moped For Sale,Electric Mop,Floor Mop Clean Machine,Cordless Floor Clean Machine,Auto Floor Cleaner
Zhengzhou Bangmi Smart Technology Co., Ltd. , https://www.cleanwindow-robot.com