NRA24 millimeter wave radar User manual (With check sum) Hunan Nanoradar Science and Technology Co., Ltd.
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Contents 1 Brief introduction of NRA24................................................................................................................ 1 2 Matters needing attention in use........................................................................................................... 1 3 Shipping list.......................................................................................................................................... 2 4 Quick-to-use steps................................
1 Brief introduction of NRA24 NRA24 is compact K-band radar altimeter developed by Hunan Nanoradar Science and Technology Co., Ltd. It adopts 24GHz-ISM frequency band, with the advantages of 2cm measuring accuracy, small size, high sensitivity, light weight, easy integration and stable performance, which satisfies the application requirements in unmanned aircraft system (UAS), helicopters, small airships and other field. Dimensions：130×70×14.
3 Shipping list The shipping list includes：NRA24 sensor 1x，as in figure 2. Figure 2 NRA24 delivery physical map 4 Quick-to-use steps 4.1 Pin definition The definition for NRA24 sensor interface pins are as shown in table1. Table 1 The definition for NRA24 pin interface Pin No. difinition value 1 POWER IN(red) 5~20 V DC 2 GND(black) - 3 TTL USART_RX(white) 0~3.3V DC 4 TTL USART_TX(yellow) 0~3.3V DC 4.
Debugging via UART interface: 1) Test tools and software are as the following table： Table 2 Product test and use tools No. Device name Qty 1 2 NRA24 PC Serial port adaptor to connect USB to TTL 12V power adaptor PC test software 1 1 3 4 5 1 1 1 2) With a USB connection to TTL serial port adaptor, to connect PC and NRA24, as shown in figure 6 .
Figure 4 Radar PC test interface 4) Start to test. NRA24 radar antenna faces directly to the moving target, or there is relatively small movement between the sensor and the target. You can see the target indicator of the red triangle in the UI interface, and the target distance R. In Figure 4, the radial distance of the target from the radar is 1.95meters (NRA24 could detect the target within 50 meters to ground).
Table 3 Format of data message Byte \ Bit 7 0 6 5 4 3 2 1 0 Start Sequence (2 x Uint8) 1 2 Message ID (2 x Uint8) 3 4 5 6 7 Data Payload (7 x Uint8 ) 8 9 10 11 Check Sum (1 x Uint8 ) 12 End Sequence (2 x Uint8) 13 The start Sequence is a constant value 0xAAAA, and the Message ID is defined as follows. The Data Payload is defined according to the Message ID (see the next section). The End Sequence is set to 0x5555.
Table 5 NRA24 configuration message format Message ID 0x200 Signal Name Bit Resolution Interval Type Comment DataType 0..6 1 0…127 u7 1: Sensor ID 2: Sensor Version 3: start/stop the target information output 4:filter the range 7e:for internal test 7f:save parameter R/W 7 1 0…1 u1 0:Read parameter; 1:write parameter Parameter 8..31 1 - u24 According to the definition of DataType Reserved 32..55 1 - - - Check Sum 56..
Note: At present, NRA24 will only return version information; other functions are not yet available. DataType indicates the configuration item, result indicates the configuration result, and Parameter is the value of the configured DataType. 5.2.1 Sensor Version After the PC or other MCU sends the read version information of sensor to NRA24, the NRA24 will return the execution result.
5.4 Targets output status (Target Status) The data message format for NRA24 system target output status is shown as in the table below. The start sequence (0xAAAA) and termination sequence (0x5555) has been omitted for the table, where the value of RollCount is continuously cycled between 0-1-2-3-0-1-2-3 ••••••. When the PC or an external MCU cannot process the output data of the NRA24 sensor in time, it will cause the received RollCount value to be discontinuous.
Note: The value of each field in the table is not the true value of the target information. The true value of the target information needs to be calculated through the following relations: - Index = IndexValue // Target ID = 1. According to Track information, NRA24 outputs only one target. - Rcs = RcsValue*0.5 – 50 // Factory test retention value, do not do output - Range = (RangeHValue*256 + RangeLValue)*0.
6 Data parsing examples Take Message ID as the target output information (Target Info) as an example, there is a frame of the Target Info data message as follows: Target Info Data: 0xAA 0xAA 0x0C 0x07 0x01 0xC8 0x07 0xD0 0x00 0x02 0xEE 0x90 0x55 0x55 Description: Start Sequence Message ID Data Payload End Sequence Interpretation： Start Sequence = 0xAAAA Message ID = 0x0C + 0x07*0x100 = 0x70C Data Payload = 0x01 0xC8 0x07 0xD0 0x00 0x02 0xEE 0x90 End Sequence = 0x5555 Each field of Data Payload is parsed
7 Electrostatic protection 7.1 Electrostatic protection measures We need take the full electrostatic protection in the radar transport and storage. When handling discrete modules that are not integrated, it is important to note that when the module is removed from the sealed antistatic package, it is time to start with electrostatic protection. Never touch or grab the radar antenna surface and connector pins, but the corner part.
A: TNRA24 adopts one transmitting and one receiving antenna, and the separation design of antennas makes the radar have a high isolation in transmit / receive link, to improve the dynamic range of radar target detection. At the same time, NRA24 utilizes the advanced integrated planar microstrip array antenna, which contains 40 vertical polarization radiation units for transmitting and receiving antennas. Therefore, it could achieve height accuracy during the effective measurement range of 0.1-50m.
FCC Caution： This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Any Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.
