PIXHAWK - Project Update

PIXHAWK Project Update

01.06.2022 - V9.73 ooopss! now  V9.731

Careful eyes spotted that I used the same pins as the tilt sensors for the PIXHAWK GPS serial.  I uploaded the V9.731 version to correct this.  Alternatively change the software serial pins to

SoftwareSerial Pixhawk_Serial(A10, A11);  // RX, TX

in the V9.73 version.

Please use the A10 and A11 pins from now on for the PIXHAWK serial.

28.05.2022 - Code 9.73 - PIXHAWK

Robot 9.73 (28.05.2022) is uploaded with basic support for the PIXHAWK. Please remember this is code to "play" with the PIXHAWK functionality and there could be some big bugs to fix still.

The Rover code must be uploaded to the PIXHAWK and the wheels set to skid steering or "R2D2 mode"


The PIXHAWK can be activated within the Mower in the new TFT GPS menu.  There are some tests available to check the connection in the TESTS menu.

Then use Quickstart and PIXHAWK to see the PIXHAWK controls.

The PIXHAWK must be armed and in one of the various modes to use the mission planner.  (The TFT arm button reaction is not so good so you may need to press it a few times).


ARM - Arns the puxhawk via the Arduino MEGA and switches the 12V relay to on. The mower is now waiting for commands from the PIXHAWK.

DISARM - Disarms the pixhawk and turns off the 12V relay

GUIDED Mode - Click on the mission planner map and the mower will drive to that GPS location.

AUTO Mode - The mower will carry out the mission as planned in the mission planner

I have added a piece of code in the specials.ino to activate the auto mission once the mower has left the charging station. This should activate the pixhawk and swap it to Auto mode.

Please remember the accuracy of the mower position is depending on the GPS accuracy of the information going to the PIXHAWK.


19.05.2022 - PIXHAWK Integration

Im a big step further along to integrate PIXHAWK and mission planner control to the mower project (Software V7.3).  I now have most of the software commands between the Arduino MEGA and the PIXHAWK up and running.  This means the Arduino can send commands to the PIXHAWK via a software serial to:

ARM, DISARM, Set AUTO Mode, Set Guided Mode, Read Volts etc.

The PWM motor output signals from the PIXHAWK are also being read by the MEGA (via pulseIn) and transfered 1:1 to the Mower Motors.  The mower can therefore decide if the PIXHAWK shall control the mower motion directly or swap back to the ReP_AL software control.

The next step is to put all the PIXHAWK hardware into the mower and test the PIXHAWK control and how well that all works in reality.

Still to go:

1. PIXHAWK Mode selection via the Blynk APP.

2. General logic of when the PIXHAWK will be in control and when the ReP_AL mower software should take over.

3. Error handling


I hope to have a very rough BETA version available soon so you can also play with this cool setup.

Im hoping this feature will allow Mission Planning and mowing of the lawn using all the features of PIXHAWK and Mission Planner.  If RTK GPS can be added it will be a very powerful feature.



17.05.2022 - PIXHAWK Update

Overview of the wiring setup for the PIXHAWK connection to the Mower PCB.  The next code update will connect to this setup.




21.11.2021 - PIXHAWK Update

I have integrated the PIXHAWK test code into the Arduino Robot Code (V9.73 to uploaded soon).

The Arduino code can now transfer PWM signals from the PIXHAWK to the mower wheel motors and Arm and Disarm the PIXHAWK via the Arduino serial monitor.  These are the first steps in running autonomous missions created in Mission Planner via the PIXHAWK.

Next step is to create the logic of when the robot will use PIXHAWK control (armed and mission started) or when the Arduino will take control (e.g. obstacle avoidance and docking)

I will update the GPS instructions to show the PIXHAWK project as a separate way to add GPS to the mower.


22.05.2021 - PIXHAWK Master Plan :)

Here's an overview of the development plan.  There are 2 basic modes.

1. Normal Arduino Control.

2. Arduino Control (Sonars, Bumpers etc) but with steering and GPS navigation from PIXHAWK


The plan is to exit the docking station as normal.  Arduino will ARM the PIXHAWK and let the PIXHAWK/GPS/ Mission Planner have control of the wheel motors.  This will guide the mower via GPS waypoints to the mission area where it can perform a mowing mission (e.g. mowing lines) .


At the end of the mow the reverse happens.  Once the mower is inside the small docking wire loop it will swap back to Arduino mode and dock as normal..



Lets see if this can be realised....

If so this could be scaled to have many mowers performing individual missions.


21.05.2021 - Pixhawk Update

Yesterday the PIXHAWK arrived and with a simple Arduino sketch i was able to Monitor the PWM Signals coming from the Pixhawk. 

This means the PIXHAWK PWM wheel motor signals can be transferred to the  Arduino which controls the mower wheel motors.  This is perfect and how I imagined to link it all together.  Now I need to find a way to control the Pixhawk from the Arduino to activate missions etc... 

02.05.2021 - PIXHAWK

I think that the best way to combine RTK GPS and a good planning experience is to combine the fantastic ARDUPILOT with the ReP_AL Mower.

I've been studying it for a while and think it will be possible to use the pin outs from the PIXHAWK to control the motors on the mower.  This would be great team, allowing easy planning in the Mission Planner and mowing via the REP_AL Mower.