OpenMower v1 Documentation – Prepare the Parts

Docs: Prepare the GPS

Mon, 01 Jan 0001 00:00:00 +0000

Info

There is a tutorial video available for this step of the process!
Check my YouTube video here: Video (time 16:21 - 17:15)

Configure the GPS board

This assumes that you are using the Ardusimple F9P GPS board.

Other GPS receivers are also supported, but need different steps:

WitMotion Unicore UM9XX: wiki, optional adapter, set-up guide

Prerequisites

A Micro USB Cable
A Windows PC
Classic u-center 1.x software:
🔗 https://www.u-blox.com/en/product/u-center
Use the classic u-center 1.x line for the F9P module.
The GPS configuration file
🔗 Robot.txt
This will open in a new browser tab. Use Ctrl+S to download the file.

Step 0: Update Firmware

Update the firmware of your Ardusimple board to version ZED-F9P HPG 1.32 - link here
There’s a guide on the Ardusimple Website.

Step 1: Open u-center and connect to your GPS

After installing u-center, connect your Ardusimple board using the “Power+GPS” USB socket to your Windows computer. You should see the blue LEDs of the board come on and Windows should recognize the device as a COM port. With the module connected to your PC, open the u-center software.

In u-center, first connect to your board by selecting the appropriate COM port in the Receiver -> Connection menu.

Step 2: Transfer the configuration to the GPS

After successfully connecting to the board, you can transfer the previously downloaded configuration file Robot.txt by opening the window Tools -> Receiver Configuration .... In this window you open the Robot.txt using the ... button and then transfer the configuration to the GPS by clicking the Transfer File -> GNSS button.

Step 3: Save configuration to Flash

In order to keep the GPS configured even after powering it down, you need to save the current configuration to Flash memory. In order to do this, select View -> Configuration View. In the new window you need to select CFG (Configuration) in the list on the left side and then enable Save current configuration. Make sure that 0 - BBR and 1 - FLASH are both selected on the right side of the window. Once that’s done, click the Send button in the lower toolbar of the window.

Step 4: Done 🎉

Your GPS is now configured for use with the Open Mower software. You can disconnect it from your Windows PC.

Docs: Prepare the SD Card

Mon, 01 Jan 0001 00:00:00 +0000

We have created a Container image that contains the Open Mower software. Additionally, we have created a Raspberry Pi image that is modified specifically for Open Mower use. In this step, we flash the image and do some basic setup for your mower.

Prerequisites

In order to follow this guide, you will need:

An SD card with at least 16 GB
A PC with the Raspberry Pi Imager Software installed:
🔗 https://www.raspberrypi.com/software/
The latest OpenMowerOS Image:
🔗 https://github.com/ClemensElflein/OpenMowerOS/releases
You can download it in the Assets section. You don’t need to unpack the image.
An SD card reader

Step 1: Flash the Image to your SD Card

Start the Raspberry Pi Imager Software. Select CHOOSE OS -> Use Custom. Then open the image file you downloaded earlier.
Select CHOOSE STORAGE and select your SD card from the Window. Make sure that you are really selecting the correct SD card, all data on the selected device will be erased!
Select WRITE and wait for the process to finish

Step 2: Configure Open Mower

For the robot to work correctly, you need to set some configuration options. In order to make this as simple as possible, the configuration files are located in the boot partition of your newly flashed SD card. You can access the files on Windows or Linux without any additional steps (it’s mounted as a mass-storage device). If the partition does not show up in your file explorer, unplug and replug the SD card.

/openmower/openmower_version.txt (on Linux: /boot/openmower/openmower_version.txt)

This file selects the Open Mower version to use. You can choose the following:

edge: Use edge for now. It is the only version which fits this guide. Most people are running this version.

In the future there will be a proper versioning system.

If you are a developer, ask on Discord how to run custom versions of the software.

/openmower/mower_config.txt (on Linux: /boot/openmower/mower_config.txt)

This file has important settings for the Open Mower software. The configurations in the file might change with the Open Mower release, that’s why the documentation can be found in the file. Here is an example file, but please use and modify the one that came with your OpenMowerOS.

Click to see annotated config code

################################
##     Important Settings     ##
################################

# Most of the time you must modify those settings, so they are moved to the beginning of document from their respective sections
# Refer to documentation for more info: https://openmower.de/docs/robot-assembly/prepare-the-parts/prepare-sd-card/#step-2-configure-open-mower

# Your Hardware Version (more a firmware version, really). Check the OpenMower docs (https://openmower.de/docs/versions/) for the firmware versions.
# Supported values as of today:
# 0_13_X: Use this if you have 0.13.x mainboard with LSM6DSOTR (default).
# 0_12_X_LSM6DSO: Use this if you have an LSM6DSOTR and have a 0.12.x mainboard.
# 0_11_X_WT901: Use this if you have an WT901 and have a 0.11.x mainboard.
# 0_10_X_WT901: Use this if you have an WT901 and have a 0.10.x mainboard.
# 0_10_X_MPU9250: Use this if you have an MPU9250 and have a 0.10.x mainboard (be aware that there are many fake chips on the market. So probably not your hardware version).
# 0_9_X_WT901_INSTEAD_OF_SOUND: Use this if you have soldered the WT901 in the sound module's slot and have a 0.9.x mainboard.
# 0_9_X_MPU9250: Use this if you have an MPU9250 and have a 0.9.x mainboard (be aware that there are many fake chips on the market. So probably not your hardware version).
export OM_HARDWARE_VERSION="0_13_X"

# Uncomment and set to coordinates near your future docking station, this will be your map origin.
# There might be a case that you don't need those if you using OM_USE_RELATIVE_POSITION=True
export OM_DATUM_LAT=48.CHANGEME
export OM_DATUM_LONG=11.CHANGEME

# NTRIP Settings
# Set to False if using external radio plugged into the Ardusimple board.
export OM_USE_NTRIP=True
export OM_NTRIP_HOSTNAME=192.168.178.55
export OM_NTRIP_PORT=2101
export OM_NTRIP_USER=gps
export OM_NTRIP_PASSWORD=gps
export OM_NTRIP_ENDPOINT=BASE1

################################
## Hardware Specific Settings ##
################################

# The type of mower you're using, used to get some hardware parameters automatically
# Currently supported:
# YardForce500
# YardForceSA650
# CUSTOM (put your configs in ~/mower_params/)
export OM_MOWER="YardForce500"

# Select your ESC type
# Supported values as of today:
# xesc_mini: for the STM32 version (VESC)
# xesc_2040: for the RP2040 version (very experimental!)
export OM_MOWER_ESC_TYPE="xesc_mini"

# Select your gamepad
# Currently supported: ps3, steam_stick, steam_touch, xbox360
export OM_MOWER_GAMEPAD="xbox360"

# Set to true to record your session.
# Output will be stored in your $HOME
# export OM_ENABLE_RECORDING_ALL=False


# Full Sound Support - But read on carefully:
# Up to (and inclusive) OM hardware version 0.13.x, DFPlayer's power supply is set by default to 3.3V.
# This is done by solder jumper "JP1" whose board track is by default at 3.3V.
# If you manually opened the 3.3V track and solder a bridge to 5V, then you can indicate it here to get full sound support.
# DO NOT enable "OM_DFP_IS_5V=True" if you haven't changed it in real. You might risk your "Raspberry Pico"!
# And even if the Pico isn't expensive, it's a torture to replace it.
# Full details are available here: https://github.com/ClemensElflein/OpenMower/blob/main/Firmware/LowLevel/README-Sound%2C%20DFPIS5V.md
# export OM_DFP_IS_5V=False
#
# Language as ISO-639-1 code string (currently only used by sound).
# Supported languages: en|de
# export OM_LANGUAGE="en"
#
# Sound volume (%)
# Supported values:
# 0-100 = Set sound volume on OM start, ignoring a previously set volume level (i.e. changed by CoverUI)
#    -1 = Don't change a previously set volume level
# export OM_VOLUME=-1
#
# Background sounds
# Beside some spoken informational advert sounds like "Waiting for RTK GPS" or "Heading back to docking station",
# the current sound implementation might also play some funny background sounds like "I'm singing in the rain" once rain got detected.
# But it will also play background sounds which might unsettle your wife or neighbor.
# That's why it's configured false/off by default. If your wife or neightbor is heavy-duty, you can set it to "true" (on) here:
# export OM_BACKGROUND_SOUNDS=False


################################
##        GPS Settings        ##
################################
# Relative Positioning vs LatLng coordinates
# If OM_USE_RELATIVE_POSITION=False, we're using an arbitrary point as map origin. This point is called the DATUM point and
# needs to be set using OM_DATUM_LAT and OM_DATUM_LONG below.
# If OM_USE_RELATIVE_POSITION=True, we're using the ublox NAVRELPOSNED messages as position.
# This makes your base station the map origin
# For it recommended to set OM_USE_RELATIVE_POSITION to False. This way you can move your base station without re-recording your maps and it's also more compatible overall.
export OM_USE_RELATIVE_POSITION=False

# GPS protocol. Use UBX for u-blox chipsets and NMEA for everything else
export OM_GPS_PROTOCOL=UBX

# If you want to use F9R's sensor fusion, set this to true (you will also need to set DATUM_LAT and DATUM_LONG.
# Consider this option unstable, since I don't have the F9R anymore, so I'm not able to test this.
# IF YOU DONT KNOW WHAT THIS IS, SET IT TO FALSE
export OM_USE_F9R_SENSOR_FUSION=False


################################
##    Mower Logic Settings    ##
################################
# The distance to drive forward AFTER reaching the second docking point
export OM_DOCKING_DISTANCE=1.0

# The distance to drive for undocking. This needs to be large enough for the robot to have GPS reception
export OM_UNDOCK_DISTANCE=2.0

# How many outlines should the mover drive. It's not recommended to set this below 4.
export OM_OUTLINE_COUNT=4

# Mowing angle offset -180 deg - +180 deg, 0 = east, -90 = north. If mowing angle offset is not absolute it gets added to the auto detected angle which is set by the first 2 m of recorded outline.
export OM_MOWING_ANGLE_OFFSET=0
export OM_MOWING_ANGLE_OFFSET_IS_ABSOLUTE=False

# The width of mowing paths.
# Choose it smaller than your actual mowing tool in order to have some overlap.
# 0.13 works well for the Classic 500.
export OM_TOOL_WIDTH=0.13

# Voltages for battery to be considered full or empty
export OM_BATTERY_EMPTY_VOLTAGE=23.0
export OM_BATTERY_FULL_VOLTAGE=28.0

# Mower motor temperatures to stop and start mowing
export OM_MOWING_MOTOR_TEMP_HIGH=80.0
export OM_MOWING_MOTOR_TEMP_LOW=40.0

export OM_GPS_WAIT_TIME_SEC=10.0
export OM_GPS_TIMEOUT_SEC=5.0

# Mowing Behavior Settings
# True to enable mowing motor
export OM_ENABLE_MOWER=true

# True to start mowing automatically. If this is false, you need to start manually by pressing the start button
export OM_AUTOMATIC_START=false

export OM_OUTLINE_OFFSET=0.05

# source the default values for the hardware platform.
# you only need this line on non-docker installs. in the docker, it will be done automatically.
# source $(rospack find open_mower)/params/hardware_specific/$OM_MOWER/default_environment.sh

Step 3: Done 🎉

You can now remove the SD card from your PC, it is ready to be used with the Open Mower software.

Docs: Prepare the Robot

Mon, 01 Jan 0001 00:00:00 +0000

Prerequisites

YardForce Classic 500
Some basic screwdrivers

Step 1: Open The Robot

The first step is to open up the robot. This is a bit tricky in some parts, so I recommend you checking my YouTube video here: YouTube Video. The relevant time is: 2:25 - 5:08.

Step 2: Remove Stock Electronics

You will need to remove these stock electronics:

Mainboard
Perimeter Sensor (slim PCB in the front of the robot).
All cables in the orange cover (emergency stop).

Keep the battery in place.

Step 3 Optional: Modify USB Socket

🧰

The kit includes compatible USB socket adapter starting version 0.12.

The YardForce classic has a USB socket on the back of the robot. Unfortunately for us, this socket has some non-standard connector on the inside.

If you want to use this USB socket on the back of the robot (for example for controlling the robot using a gamepad like shown in the first video), you will need to add a USB A plug to the USB cable and plug it into the Raspberry Pi.

This way the USB port at the back of the robot is wired directly to the Raspberry Pi.

Docs: Prepare the Mainboard

Mon, 01 Jan 0001 00:00:00 +0000

Info

If you have bought the hardware kit, the mainboard already has firmware installed, but it’s a good idea to update it to the latest version anyway.

If you have just soldered the mainboard yourself, you will need to upload firmware once via USB. This is because without the firmware, the main Raspberry Pi won’t turn on.

For this, follow the Manual Firmware Installation guide.

Docs: xESC boards

Mon, 01 Jan 0001 00:00:00 +0000

The Kit includes 2 wheel xESCs and 1 mower motor xESC, configured and ready to go. They are identical in hardware, only XML configs differ.

Configuring xESCs is described here.

Docs: Sound (DFPlayer)

Mon, 01 Jan 0001 00:00:00 +0000

DFPlayer Module

If your mainboard got delivered with an already equipped DFPlayer, you most likely got the original DFRobot-DFPlayer with a ‘DFRobot LISP3’ chip.

If you need to attach one, and your’re not located in the US, you might also use a DFPlayer-Clone with a ‘MH2024K-24SS’, ‘JL AB23A799755’ or ‘GD3200B’ chip, as sold by Amazon, AliExpress or the like.

☝️

When using a DFPlayer-Clone,
in an open-mower-mainboard up to version 0.13.x,
you should cut-off Pin-11 from the DFPlayer-Clone:

If not, volume control will not work and always play at 100%!

☝️

You also need to take attention that your motherboard has the required R7 and R13 (1k) resistors assembled:

Change DFPlayer’s V_CC to 5V

All mainboard version ≤ 0.13.x supply the DFPlayer with 3.3V by default. But for full sound support, it’s highly advised to change this to 5V, otherwise you might risk your Pico’s PMIC 💣. More technical details here: Sound-Readme

Don’t forget to cut the trace between middle and 3.3v! It’s there, even if it’s barely visible! (if you forgot, you’ll bridge the 3v3 with 5V resulting in incorrect battery voltage reporting)

Once changed, you’re save to enable full sound support via OM_DFP_IS_5V=True mower_config switch.

Sound SD-Card

🧰

SDCard (128Mb) and DFPlayer Mini are included in the kit.

Take an SD card (different from the one you are using for RPi), format as FAT32, copy all MP3 files and folder to the root folder. Insert SD card to DFPlayer. Insert DFPlayer into motherboard SD card facing right (towards RPi)

☝️ Updated 11/2024

The soundfile structure completely changed in November 2024. If you already prepared your SD-Card before, it still works, but for full sound support you need to replace all files with the new structure (and take care that no old origin files remain on the SD-Card).

Speaker mount

There’re a couple of 3D-Printable speaker mounts available for different models. Worth to check OpenMower @ Printables

OpenMower v1 Documentation – Prepare the Parts

Docs: Prepare the GPS

Info

Configure the GPS board

Prerequisites

Step 0: Update Firmware

Step 1: Open u-center and connect to your GPS

Step 2: Transfer the configuration to the GPS

Step 3: Save configuration to Flash

Step 4: Done 🎉

Docs: Prepare the SD Card

Prerequisites

Step 1: Flash the Image to your SD Card

Step 2: Configure Open Mower

/openmower/openmower_version.txt (on Linux: /boot/openmower/openmower_version.txt)

/openmower/mower_config.txt (on Linux: /boot/openmower/mower_config.txt)

Step 3: Done 🎉

Docs: Prepare the Robot

Prerequisites

Step 1: Open The Robot

Step 2: Remove Stock Electronics

Step 3 Optional: Modify USB Socket

🧰

Docs: Prepare the Mainboard

Info

Docs: xESC boards

Docs: Sound (DFPlayer)

DFPlayer Module

☝️

☝️

Change DFPlayer’s VCC to 5V

Sound SD-Card

🧰

☝️ Updated 11/2024

Speaker mount

Change DFPlayer’s V_CC to 5V