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Preface
This article describes how to configure a telemetry radio using Mission Planner .
！Tip
Many users do not need to configure the radio! But when you use the aircraft with others, you may need to configure the radio channel ( Net ID ).
1 Overview
Mission Planner supports configuring radio devices using a simple graphical user interface.
Make changes:
- Connect one of the radios to the computer using a micro USB debug cable;
- Insert the aircraft battery to power the radio connected to the aircraft;
- Open Mission Planner and enter the Initial Settings | Optional Hardware | SiK Radio page;
- Select the correct COM port and set the baud rate to 57600 . Make sure the " Connect " button is disconnected, as shown in the picture below;
- Press the " Load Settings " button and both the local and remote areas will be filled with values, including the firmware version;
- The most commonly changed item is the network ID . The default value for most radios is 25 , but if you plan on flying in an area with other pilots who may be using the same radio, it's best to change it to another number;
- After making changes, click " Copy required items to remote " and press " Save settings ".
2 Parameter description
You can choose to update other parameters:
Baud (default 57 ): The rate at which the mission planner or aircraft communicates with the local radio. " 57 " = 57600 bits per second.
Air Speed (default 64 ): The communication speed between two radios. " 6 4" = 64kbps (kilobits per second). Setting a lower rate increases the range of the radio, but reduces the data transfer rate on the link (i.e., the amount of data that can be sent in a given time).
ECC (default is " on "): Controls whether error correction is on or off. When turned on, " 12/24 Golay Error Correction Code " is used, that is, a 16 -bit CRC byte is sent at the same time as the data is sent to ensure that bad data is discarded. Unfortunately, this will also halve the data transfer rate of the entire link, but we recommend turning on ECC , especially when the aircraft is far from the base, as transmission errors increase significantly with distance.
MAVLink (default " MAVLink "): Controls whether the transport is optimized for MAVLink packets. If you are flying the aircraft manually using a joystick or an Android tablet's virtual joystick, set it to " Low Latency ". Note thatradio signal strength ( rssi ) and error rate information are only sent when this parameter is set to the default " MAVLink ".
Tx Power (default 20 ): Transmit power, where 1=1.3mW , 2=1.5mW , 5=3.2mW , 8=6.3mW , 11=12.5mW , 14= 25mW Watts, 17=50 milliwatts, 20=100 milliwatts. This should be set up according to local regulations. Some country information is linked here
Duty Cycle (default 100 ): The maximum percentage of time the radio sends packets. Some areas of the world allow higher transmit power or more frequencies if the duty cycle is below a given threshold. For example, in Europe, if the duty cycle is below 10% , transmission can be performed on more frequencies in the 433 band. Telemetry traffic is quite " bursty ", so the average transmission time is generally not very long. If you set the duty cycle below 100% , the available bandwidth is reduced, so telemetry only works well at higher airspeeds. The radio can be set to receive only by setting the duty cycle to zero.
Max Window (default 33 ): Ensure that GCS sends a data packet to the aircraft within33ms . This value should stay low (like 33 ) when " MAVLink " is set to " Low Latency " .
LBT Rssi (default 0 ): Maintains the " listen before speaking " threshold to comply with regulatory requirements in some countries. If non-zero, the radio listens for a quiet time when no other radio signals are received before transmitting. This parameter sets the receiver signal strength below which waves are considered " quiet ". If this parameter is set to zero, LBT is disabled . When setting it to 25 (minimum), the signal strength is -121dBm . Every 0.5dB increase in threshold above 25 , for example, 40 is equivalent to a signal strength of 7.5dB . The complete formula is as follows:
signal_dBm = (RSSI / 1.9) - 127
According to the European 9.2.2.2 rules, the LBT implementation in the radio uses a minimum listening time of 5ms and a random listening time. Note that in many areas you will need to implement LBT in conjunction with AFA (Adaptive Frequency Flexibility) . The radio can implement AFA as long as NUM_CHANNELS is set above 1 .
RTS CTS hardware flow control. If you are using an ArduPilot firmware version released after mid-2016and have the radio connected to a Pixhawk Telem1 Telem2 or other RTS/CTS capable telemetry port, you can activate this feature, or set it to automatic to improve performance.