How to configure the parameters of the FPV VRX module
Our FPV VTX module is equipped with an optional parameter configuration board, which is a pluggable tool.
However, some customers still want to use serial port tools to send serial port commands to read or adjust parameters for remote automation.
Below I have sorted out the instructions for the FPV VRX receiving module, hoping to provide customized technical support for your project. If there is anything unclear, please contact us.
Configure the parameters of the FPV VRX module
Table of Contents
FPV VRX Module Feature
- Small size. Length 97MM, width 80MM, height 20MM
- Low power consumption, power consumption 1.8W
- High receiving sensitivity. OK -100dBM
- Good compatibility. Supports 8M, 7M, 6M, 5M, 4M, 3M, 2M, 1M bandwidth, frequency 46MHz~860MHz.
- Wide voltage power supply. Power supply voltage range: 8V~20V.
FPV VRX Module configurable Parameter
- Supported parameters
- IFFT：2k
- Guard interval: 1/4, 1/8, 1/16, 1/32
- FEC：1/2、2/3、3/4、5/6、7/8
- Modulation mapping: QPSK (4QAM), 16QAM, 64QAM
- Bandwidth: 8M, 7M, 6M, 5M, 4M, 3M, 2M, 1M
- Frequency: 46MHz~860MHz
- Support encryption function (cooperated with modulation board)
- Supported keys are 128 bits.
- One-way transparent serial port
- The module supports a one-way transparent serial port transmission.
- 8 data bits
- 1 stop bit
- Support odd parity, even parity, no parity
- Baud rate: 1200, 2400, 4800, 9600, 19200, 38400
- 57600、115200、230400
- Communication control serial port parameters
- 8 data bits
- 1 stop bit
- even parity
- Baud rate: 19200
FPV VRX Module interface, dimensions and signal definitions
1. Demodulation module picture
Module electrical performance
- Voltage: 12V DC, voltage range 8V~20V
- Current: 150mA (12V)
FPV VRX Module configuration parameters
RAM Parameter Description
The module configuration parameters are all implemented by writing to a 256×8 RAM inside the module. The configured parameters are valid after saving reset or powering on again. After the system is powered on or reset, the serial port will print {AAAAAA}
RAM Parameter Details
RAM[0]: System reset control, readable and writable, reading and writing have different meanings
Write:
- 00 => Reset the entire system, the serial port returns {AAAAAA}, indicating that the system has been reset.
- 01=> Save 256 RAM values, and the serial port returns {000101}, indicating successful execution.
- 02=>Restore the value of 256 RAM to the system default initial value, and the serial port returns {000202}, indicating execution success
- 03 => Search for the frequency point of the specified bandwidth. The serial port returns {000303}, indicating that the execution is successful.
- 04=> Search the specified frequency when the parameters are known, and return {000404}, indicating successful execution.
- 05 => The decryption key takes effect, and the serial port returns {000505}, indicating successful execution.
- 06=> Send the infrared code to the playback board, and put the infrared code in RAM [63]
- Others => Reserved
Read:
- Bit[7:4]: Serial port rate
- “0000” =1200,
- “0001”=2400,
- “0010”=4800,
- “0011”=9600,
- “0100”=19200,
- “0101”=38400,
- “0110”=57600,
- “0111”=115200
- “1000”=230400,
- “1001”~”1111″=reserved
- Bit[3]: Parity parity
- ‘0’=even effect,
- ‘1’=miraculous effect
- Bit[2]: Parity switch
- ‘1’=on
- ‘0’=off
- Bit[1]: Main DIB9090M frequency lock indication
- ‘1’=frequency lock
- ‘0’=frequency not locked
- Bit[0]: Frequency lock indication from DIB9090M
- ‘1’=frequency lock
- ‘0’=frequency not locked
RAM[1]~RAM[2]: Specified search frequency point, in 100KHz unit, readable and writable, RAM[1] is the high bit
RAM[3]: The bandwidth of the frequency point, in units of 100KHz, can be read and written, ranging from 10 to 80, and the bandwidth represented is RAM[3]/10
Such as 11 => 1.1M;
22 => 2.2M
RAM[4]~RAM[13]: channel parameters
struct dibDVBTChannel {
int8_t spectrum_inversion;
int8_t nfft;
int8_t guard;
int8_t constellation;
int8_t hrch;
int8_t alpha;
int8_t code_rate_hp;
int8_t code_rate_lp;
int8_t select_hp;
int8_t intlv_native;
} dvbt;
RAM[14]: The working mode of the board after power on, default value 00
- 00 => Search channels according to the frequency specified by RAM[1]~RAM[2] and the bandwidth specified by RAM[3]
- 01=> Search the channel according to the frequency specified by RAM[1]~RAM[2], the bandwidth specified by RAM[3] and the channel parameters specified by RAM[4]~RAM[13]
Other reservations
RAM[15]~RAM[30]: Decryption key, readable and writable, default value is all zeros
RAM[15]: Bits [127 to 120] of the 128-bit encryption key
RAM[16]: Bits [1119 to 112] of the 128-bit encryption key
RAM[17]: Bits [111 to 104] of the 128-bit encryption key
RAM[18]: Bits [103 to 96] of the 128-bit encryption key
RAM[19]: Bits [95 to 88] of the 128-bit encryption key
RAM[20]: Bits [87 to 80] of the 128-bit encryption key
RAM[21]: Bits [79 to 72] of the 128-bit encryption key
RAM[22]: Bits [71 to 64] of the 128-bit encryption key
RAM[23]: Bits [63 to 56] of the 128-bit encryption key
RAM[24]: Bits [55 to 48] of the 128-bit encryption key
RAM[25]: Bits [47 to 40] of the 128-bit encryption key
RAM[26]: Bits [39 to 32] of the 128-bit encryption key
RAM[27]: Bits [31 to 24] of the 128-bit encryption key
RAM[28]: Bits [23 to 16] of the 128-bit encryption key
RAM[29]: Bits [15 to 8] of the 128-bit encryption key
RAM[30]: Bits [7 to 0] of the 128-bit encryption key
Description [127 to 0] are all 0, no encryption is used
Main DIB9090M
RAM[32]~RAM[35]: used to calculate signal-to-noise ratio, please refer to relevant documents for details
RAM[36]~RAM[37]: Calculate RF power, see the code for rf_power details
RAM[38]~RAM[40]: Calculate RF power, n_agc_power specific parameter code
From DIB9009M
RAM[41]~RAM[44]: used to calculate signal-to-noise ratio, please refer to relevant documents for details
RAM[45]~RAM[46]: Calculate RF power, see the code for rf_power details
RAM[47]~RAM[49]: Calculate RF power, see the code for n_agc_power details
RAM[127]: BIT[0]= 1 SLAVE DIB9090 initialization failed (if the main dib9090 initialization fails, the board will continue to restart)
Other RAM is reserved and its contents cannot be read or written.
FPV VRX Module configuration commands
Configuration commands are implemented by sending commands to it through the serial port.
Command format: {+opcode+RAM address+<operand>+check code+} The symbols {} are all hexadecimal numbers represented by ASCII codes.
{ : indicates the start of the command
+: Indicates that this only represents the connection, which is used for illustration and does not exist in the actual command.
<>: Indicates that the parameter is not included in the read command.
} : indicates the end of the command
Opcode: 00 means write, FF means read, 1 byte
RAM address: 1 byte
Operand: The operand of the command is 1 byte. In the read operation, this byte has no
Check code: (opcode + storage address + <operand>) mod 256
Command return format:
The return format if the operation is successful: {+register address+register value+check code+}
The reset command did not return
Operation failure return format: {FFFFFF}
How to configure the parameters of the FPV VRX module is suitable for the below model.
[VF-202407]