Version vom 2. November 2015, 11:04 Uhr

Abstract

This page describes how to assemble the Ardumower PCB, flash the Arduino and configure the robot mower.

The controller is built around a ready microcontroller board (Arduino Mega 2560 using 54 I/O pins).

• 

  Components overview

• 

  Chassis components

• 

  Ardumower's heart: Arduino Mega 2560 microcontroller

• 

  Modules available in the shop

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  Ardumower PCB connects all modules (available in the shop)

• 

  Chassis and PCB inside

• 

  PCB mount

Needed modules

All modules can be purchased as complete kits via the shop .

What is needed for the development of Ardumowers.

• The Ardumower chassis including motors and motherboard

• Important modules to choose::
  • Zubehör Set (Widerstände, Stiftleisten etc.)
  • 2 x Protector Board
  • 1 x Mega Board 2560 R3
  • 1 x INA169 Strom Sensor Board
  • 2 x Dual Treiber MC33926
  • 3 x DC-DC LM2596 Step-Down Regler
  • 1 x Wireless Bluetooth Modul HC-05
  • 1 x Real Time Clock I2C DS1307
  • 1 x 24 VoltLadegerät für den Ardumower Akku

• Optional modules::
  • Zubehör Set Ladeschaltung (Blei Akkus)
  • WIFI Wlan Modul ESP8266 ESP01
  • Ultraschallsensoren HC-SR04 (bis zu 3 Stück werden unterstützt)
  • Regensensor
  • GPS Modul GY-GPS6MV2
  • GYRO-80

• 1 x Ardumower Power Pack

• 1 x 3 Messer + 3 Schrauben passend z.B. für Automower® von Husqvarna®

• 1 x Perimeter Sender Board (Prototyp) mit Platinen Zubehör
• Important modules to choose::
  • 1x Dual MC33926 Motor Driver Carrier
  • 1x INA169 Analog DC Current Sensor Breakout - 60V 2,5A / 5A Marotronics
  • 1 x DC-DC Spannungsregler LM2596 Step-Down Regler einstellbar
  • 1 x Nano V3.0 ATmega328-AU Arduino kompatibel Mikrocontroller Board

• Optional modules::
  • Gehäuse inklusive 5 passender Schrauben für das PCB
  • Anschlussklemmen max.3 (2xSchleife, 1xLadeanschluss)
  • Einbaubuchse für Gehäuse 2,5

• Additional accessories depending on needs:

• • Rasennägel/Heringe
  • Kabel für die Schleife

• A charging station is in development and will follow soon.

PCB

The printed circuit board (PCB) connects all electronic modules. The PCB is made with the following design parameters:

• PCB dimensions 241x114mm
• All modules (motor driver, Bluetooth, etc.) can be soldered (or plugged) on the PCB (modules are available in the Ardumower shop)
• Uses the Arduino Mega 2560
• Optional: can use Arduino Due via additional adapter PCB
• Optional: integrated charging circuit (current limiting)
• All connections are available on connectors as well as +5V and GND
• Max. trace current (for motors): 8A

PCB versions

Robot PCB v0.5 (initial prototype)

• Photos
• Schematics
• Build instructions
• Build instructions (English translation)

Robot PCB v1.2 (minor layout changes)

• Schematics
• Photos
• Build instructions
• Build instructions (English translation)
• WorkaRound20150527
• WorkaRound20150530
• Motor-decrease noise REV20150531, (English comments)
• Protector board

Robot PCB v1.3 (in development)

• simplified design (Due adapter will be externally)
• motor driver protection
• battery-off circuit, safety-button
• sets 'reference-design' and required modules: 3x DC/DC, RTC, IMU

NOTE: The schematics and PCB files were created with KiCad. They can be downloaded from github and can be edited by open source KiCAD software (Download here or here).

PCB jumpers

PCB modules

PCB connectors

Power supply

Please also read the section 'Voltages' under Motor driver for more information on motor voltages.

It is recommended to use a voltage step-down converter (e.g. module using LM2596) to generate the 5V voltage for the Arduino and all additional modules. Before connecting, set the voltage of the converter to 5V.

Warning : never connect more than 5V on the Arduino 5V pins, or you will damage the Arduino. Therefore, always measure the 5V voltage before connecting it to the Arduino 5V pin! All components together (as shown in the schematics) need about 5W power.

• 

  NOTE: Keep away coil/pre-amplifier from DC/DC converters!

Download and flash Arduino code

NOTE: If you have never worked with Arduino before, read our 'Arduino first steps' introduction.

You have two options:

• Download github code (recommended) OR
• Download v0.9.3 code (old, not recommended)

Finally, download and start the Arduino IDE to flash the code to your Arduino.

Arduino Version: It is very Importent that you use the Arduino IDE version 1.6.3 or above AND select the right Board (Mega 2560 or Due).

Note: Always verify that the pin configuration in your Arduino code (config.h/mower.cpp) matches your actual circuit!

First-time calibration

Wheel motors

Security note: For security reasons, always remove mower blades in your first tests!

Initially, you should verify that the wheel motors are controlled correctly and in the right direction. The software offers a diagnostic mode. Open the serial console in the Arduino IDE (CTRL+SHIFT+M) and set the baudrate to 19200. The motor and sensor values should appear constantly:

    20 OFF  spd    0    0    0 sen    0    0    0 bum    0    0 son...
    21 OFF  spd    0    0    0 sen    0    0    0 bum    0    0 son...
    22 OFF  spd    0    0    0 sen    0    0    0 bum    0    0 son...
    23 OFF  spd    0    0    0 sen    0    0    0 bum    0    0 son...
    24 OFF  spd    0    0    0 sen    0    0    0 bum    0    0 son...
    ...

Now, press the key ‘t’ on the keyboard, and confirm using ENTER. The diagnostic mode should appear, and you can test your motors.

ADC calibration

Run the ADC calibration once (either via serial console with command 'd' or "pfodApp->ADC Calibration"), so that the received signal is symmetric around zero.

Diagnostics/troubleshooting

Each time a sensor triggers, its corresponding sensor counter increases. The sensor trigger counters as well as the current sensor values can be viewed on the serial console. The following values are shown for the trigger counters in the serial console:

1. Time of state machine's state (ms)
2. loop()-counts per second
3. choosen Verbose-Mode (0=counter readings/1=current values/2=current values)
4. current state machine state (FORW, REV, ROLL etc.)
5. drive home? (1/0)
6. "spd" - Control/speed motors: left (PWM), right (PWM), mower (RPM)
7. "sen" - Current limit exceeded counter motors: left, right, mower
8. "bum" - bumper counter: left, right
9. "son" - Ultrasonic-distance threshold exceeded (counter)
10. "pit/roll" - Tilt (computed by acceleration sensor)
11. "com" - compass course
12. "per" - Perimeter loop detected: counter
13. "bat" - Battery voltage
14. "chg" - Charging current

Using the key 'v', you can toggle between sensor trigger counters and current sensor values.

Additionally, you can use pfodApp (Android) to plot the sensors (trigger counters and current values) over time. This allows you to wirelessly monitor your robot mower for error diagnostics. It is highly recommended.

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  Sensor trigger counters

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  Sensor measurement values

Starting the mower

To start the mower, you need to add a button and a buzzer:

pinButton —o Button o— GND (button for ON/OFF)

pinBuzzer —o Buzzer o— GND (Piezo buzzer)

Now, press the button as long as you hear the beeps:

Mode (press button for x beeps):

1 beeps : Normal mowing (using blade modulation if available)
2 beeps : Normal mowing (without blade modulation)
3 beeps : Drive by model remote control (RC)
4 beeps : Drive without mowing
5 beeps : Find perimeter and track it

Error counter / error beeps

If there's a communication problem or another serious problem, the error counter increases. The error counter can be monitored via pfodApp. Additionally, the robot mower will beep when started.

See section Troubleshooting for details on all errors.

I2C bus / error beeps

Several components (Arduino Nano, RTC, IMU, etc.) are communicating via the I2C bus (SDA/SCL wires). These wires should be very short (maybe even twisted) and they should be far away from DC converter and motor drivers. If there's a communication problem, the error counter will increase and robot will beep when started. The error counter can be monitored via pfodApp.

Settings

The robot uses settings that you can adjust for your own robot and environment (via pfodApp or directly in the code). The default settings (factory settings) are stored in the config file 'mower.cpp'.

The settings can be adjusted via Android phone (pfodApp).

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  General settings

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  Motor speed settings

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  General config file idea

Important: If you uploaded a new version into your robot, reset all settings via pfodApp once (Settings->Factory reset). This will delete all existing settings. Old settings can produce malfunction if the internal settings format has changed.

Further links