All GPIO & function small size PX4 for UAV research for HKUST UAV-Group

Dimension of NxtPX4: 27mmx32mmx8mm

Hardware quick review

1. clone repo.
2. run init repo script: ./init_all_repo.sh it will take some time to clone all submodules into loccal
3. Enter directory NxtPX4-Hardware: cd ./NxtPX4-Hardware you should notice that you are not on main branch, So Checkout to main branch using: git checkout -b main
4. cd back to NXTPX4 dir
5. Enter directory PX4-Autopilot: cd ./PX4-Autopilot you should notice that you are not on main branch or develop branch. So checkout main branch to local and then checkout to develop branch to compile frameware for NxtPX4. git checkout -b main and then git checkout -b develop origin/develop
6. configure done !

We found a silkscreen printing error on the USART 1 and 2 of the V1.2.3 PCB. The labels for Tx and Rx are incorrect. Please follow the silk screen in the modified version V1.2.3.1(picture below)

The only difference between v1.2.3 and v.1.2.3.1 is the silkscreen of USART1 and USART2

(connection for v1.2.3)

Basic connection with receiver & ESC & computer

If your receiver uses Sbus please connect the pads in red circle

1. go to PX4-Autoplilot directory
2. using make hkust_nxt_bootloader to compile bootloader
3. Press boot button on board and then connect it with computer, flash bootloader with Betaflight configurator or STM32programmer
4. using make hkust_nxt to compile firmware, and flash .px4 through QGC

1. compile firmware ./start_docker.sh hkust_nxt
2. compile bootloader ./start_docker.sh hkust_nxt_bootloader

Set power_source Power Module, then calibrate voltage and current analog data

Set RC_PORT_CONFIG with Radio controller

Set MAV_0_CONFIG with TELEM 2

create file in your tf-card /etc/extras.txt

mavlink stream -d /dev/ttyS3 -s ATTITUDE -r 200

mavlink stream -d /dev/ttyS3 -s HIGHRES_IMU -r 1000

then using the following settings

IMU_GYRO_RATEMAX: 2000Hz

IMU_INTEG_RATE: 400Hz

MAV_0_MODE: External vision

Set Uart4 to 921600

MAV_0_RATE 92160B/s

after these settings you will have approximate 500Hz /imu/data_raw /imu/data

if you want to have presice 500Hz imu/data_raw and 200Hz imu/data

SYS_MC_EST_GROUP: Q attitude estimator

• Kicad 7.0 required
• Create new branch for your own features
• Only general hardware features can be merged into main branch

in v1.0.1 design, the original idea is to make ESC connector order weird, to make user notice the PINOUT sequence, however in practice, Rx pin is too close to Vbat pin, which leads to MCU damage at the moment power on or off if the cable is not titely installed. Noticing that, in v1.1.0 design, we change the ESC pinout order.

The pre-build firware and bootloader are in ./firmware dir, donwload and flash in corresponding with your hardware version

• Frameware compile: make hkust_nxt
• bootloader compile: make hkust_nxt_bootloader

• Frameware compile: start_docker.sh hkust_nxt
• bootloader compile: start_docker.sh hkust_nxt_bootloader

• Create new branch named as feature-xxx(feature info) from develop branch to start your own feature development
• After test your own feature, mereged into develop branch and push a pull request (only general features will be accepted)

update repo using script: ./update_all_repo.sh

• Develop branch back to normal HIGHRES_IMU
• remove MPU6500
• replace 0420 Inductor with 05xx inductor
• refine pinout (v2.0 hardware)

TODO

1. ESC RPM report cannot run with MAVRos /mavros/imu/data