DJI Flamewheel 450 with distance sensor and RTK GPS
Parts List
- Autopilot: Pixhawk 3 Pro
- Frame: DJI Flamewheel 450
- Motors: 3DR Iris Plus 950kv repranded T-Motors MN2213
- ESCs: Hobbywing XRotor 35A Micro 3-6S BLHeli
- Blades: Graupner 10"x5" (You need to print these adapters to be M6 compatible)
- Distance sensor: Lidar-Lite V3
- GPS: Here+ RTK GPS
- Telemetry: 3DR Telemetry
- Battery: Roxxy LiPo - 4S, 4000mAh
In addition we use a FrSky X4R-SB 3/16ch 2.4Ghz receiver and a FrSky Taranis controller. You will also need zip ties, double sided tape, a soldering iron and a 3D printer in case you use the same Blades, for this build. The GPS mast was reused from an Intel Aero.
The Pixhawk 3 Pro can be attached using the double sided tape because the IMU inside is already dampened.
Wiring and connections
General pinout for the Pixhawk 3 Pro can be found here.
3DR Telemetry
The 3DR Telemetry does not come with a JST GH connector which the Pixhawk 3 Pro uses. The pinout remains the same and just the plug needs to be changed. Use the Telem 1 port on the Pixhawk 3 Pro.
| pin | Pixhawk 3 Pro Telem 1 | 3DR Telemetry |
|---|---|---|
| 1 | VCC | VCC |
| 2 | TX | RX |
| 3 | RX | TX |
| 4 | CTS | CTS |
| 5 | RTS | RTS |
| 6 | GND | GND |
Lidar-Lite V3
The pinout for the Lidar Lite V3 and the Pixhawk 3 Pro I2C 1 port is as follows.
| pin | Pixhawk 3 Pro I2C 1 | Lidar Lite V3 |
|---|---|---|
| 1 | VCC | VCC |
| 2 | SCL | - (Power enable) |
| 3 | SDA | - (Mode control) |
| 4 | GND | SCL |
| 5 | - | SDA |
| 6 | - | GND |
Here+ RTK GPS
The Here+ GPS comes with an 8 pin connector suited for the Pixhawk 2. In order to use it with the Pixhawk 3 Pro (or a Pixracer), a 6 pin connector has to be used and pin 6 and 7 are not needed (see below). The additional pins are for the safety button and can be attached as well if needed. More information on the pinout can be found in this document, page 17.
| pin | Here+ GPS | pin | Pixhawk 3 Pro GPS |
|---|---|---|---|
| 1 | VCC_5V | 1 | VCC |
| 2 | GPS_RX | 2 | GPS_TX |
| 3 | GPS_TX | 3 | GPS_RX |
| 4 | SCL | 4 | SCL |
| 5 | SDA | 5 | SDA |
| 6 | BUTTON | - | - |
| 7 | BUTTON_LED | - | - |
| 8 | GND | 6 | GND |
Parameters
General documentation on how to setup your quad in QGC can be found here.
Airframe
Select the airframe DJI Flame Wheel 450 in QGC -> Airframe -> Quadrotor x.
Lidar-Lite
To enable the Lidar-Lite V3 (connected via I2C), the parameter SENS_EN_LL40LS
has to be set to 2. This can be done using the NuttX shell and the command
param set SENS_EN_LL40LS 2. See
here how to get a shell (Note that
this is only a temporary solution, because QGC currently doesn't
support setting the value to 2 directly).
RTK GPS
RTK GPS is plug and play. For more instructions see here.
Others
Set the following parameters as well:
EKF2_HGT_MODE=2: this makes sure the Lidar-Lite is used as height sourceMAV_PROTO_VER=2: use Mavlink protocol version 2CBRK_IO_SAFETY=22027: disable the safety buttonEKF2_GPS_POS_X,EKF2_GPS_POS_Y,EKF2_GPS_POS_Z: set the GPS device offset with respect to the board (NED coordinates).