Introduction

BURRO uses an RTK (real-time kinematic) base station to run most of its autonomous modes. This RTK base station is required to run Teach & Repeat and Loops. Before a typical day of operation, the base station should be placed somewhere secure where it can stay in place without being moved the entire time BURROs are running, where it has a clear view of the sky. The BURRO Generation 3 Base Station is the latest RTK base station that is compatible with BURRO Gen 6, BURRO Gen 7, and BURRO Gen 8 models. This new base station has the upgraded capacity to support two working modes: Survey-in Mode and Fixed Mode, which will be explained in further detail later on in this guide.

Base Station Control Panel

The Gen 3 Base Station’s Control Panel contains a power button (lit up by a green LED), a battery level indicator that uses four orange LED bars that indicate the base station’s battery level and charging status, and a survey-in status LED indicator.

• To turn on the base station: Press the Power Button as shown below

• To turn off the base station: Press and hold the Power Button for about 2 seconds until the Power Button LED and all other LEDs turn off 

LED Indicators

Power Button Indicator:

Solid Green: Base station is powered ON

Off: Base station is powered OFF

Battery Level Indicator:

Flowing Orange Bars: Base station battery is charging

Solid Orange Bar(s): Indicates the remaining amount of battery charge when the base station is turned on

4 Bars: < 100% charge remaining

3 Bars: < 75% charge remaining

2 Bars: < 50% charge remaining

1 Bar: < 25% charge remaining

Survey-in Indicator:

Blinking Green: Survey-in is in progress

Solid Green: Base station is surveyed-in and is actively transmitting correction data to BURRO units paired to it

Solid Blue: Base station is in “Fixed Mode”

Solid Red: Survey-in process timed out (went over 8 minutes without obtaining a successful survey-in)

Note: This base station unit’s survey-in process lasts for up to 8 minutes, in which time if it can’t acquire its location (due to weak satellite signal or any other inconclusive reason) the unit’s SURVEY LED will change to solid red. If this occurs, this means the survey-in process failed, and the base station should then be powered off and powered back on again to retry the surveying-in process.

If the base station still fails to survey-in properly, you may try changing the base station’s location, then power cycling the unit and restarting the survey-in process. If the base station for whatever reason still cannot survey-in properly after several power cycles, please contact BURRO Support (Contact information can be found on the base station unit or any BURRO unit nearby.

Base Station Modes

Survey In Mode

In “Survey-in” mode, the base station will try to acquire satellite signals to obtain its location

coordinates, providing correction data for robots paired to it so as to obtain accurate positioning.

When the base station is first powered on, the SURVEY LED will begin blinking green. This blinking indicates that the unit’s position acquisition is in progress. When the base station has obtained its location coordinates (within the preset deviation), it will lock into the “Survey-in” stage, where it will begin to broadcast correction data to all BURRO units paired to it. Once the base station is surveyed-in, the SURVEY LED will then stop blinking and change to a solid green state. Only after the base station is surveyed-in can the user then train routes on BURROs paired to that base station using Teach & Repeat.

In this mode, the base station only retains a valid survey-in status as long as the unit is not powered off and is not physically moved. Whenever the base is turned off or moved to a different location, the base station would need to redo the survey-in process after powering back on to get its location information again. Only after the base station is properly surveyed-in can BURROs be used again in Teach & Repeat. Each BURRO that has trained routes using that base station must have all of its routes retrained each time the base station is power cycled (after waiting for the base station to survey-in again). 

Fixed Mode

For situations where the base station can be installed permanently (or semi-permanently) in a secure location, “Fixed Mode” allows for the base station to save its GPS position after it’s been power cycled or powered off. The base station will save its previous surveyed-in GPS position and use it again as before when the base station is powered back on. In this mode, the base station would not need to go through the survey-in process again when it’s power cycled. The base station takes the saved coordinate information which was collected from the most recent survey-in process as its current location data instead of initializing a new survey-in process, so routes do not need to be retrained on any BURRO units paired to it if the base station loses power, is moved, and/or is turned off. Simply ensure the base station is powered back on before any BURRO units continue using routes in AUTO mode, and the SURVEY LED indicator is a solid blue color.

Base Station Fixed Mode Installation

Location requirements to properly mount base station for fixed mode installation

1. Select a location that is central to where Burros will be used and power could be provided.

2. The base station should have a clear view of the sky. The base station should not be under any roof. 

3. The base station should be mounted as high as possible to get better reception and range. 

Instructions for fixed mode installation

1. Open the yellow carrying case and pass the waterproof usb-c cable through the cable gland.

2. Secure the tripod to a pole or to a wall.

3. The carrying case power plug should not face upwards any other side is good. The best practice is to mount the carrying case where the power plug is facing downwards. See the diagram for orientation and required materials and orientation of the base station and carrying case
   

   1. The examples below show using the included tripod to have a semi-permanent installation.
      
4. Zip-tie the USB C cable which connects the carrying case and the base station in a way that provides strain relief as shown below.
   
5. Zip-tie or install a bracket over the power plug to the carrying case so it doesn’t become unplugged due to inadvertent weather.
   

Switching Modes

The Gen 3 Base Station by default comes in “Survey-in Mode”. To switch the base station to “Fixed Mode” and ensure it works properly, the base will need to first survey-in using the default “Survey-in Mode”. Wait until the base station is surveyed-in (SURVEY LED turns from blinking green to solid green) before attempting to change the base station to “Fixed Mode”. Once you are sure the base station is surveyed-in, “double press” the Power Button:

• Press the power button once, then immediately take your finger off and press it again, this time holding down the button until the SURVEY LED (survey-in indicator) turns solid blue. The base station should now be in “Fixed Mode”. If the double press does not register properly, wait two seconds and try again.

• To switch the base station back from “Fixed Mode” back to “Survey-in Mode, simply double press the power button again as before.

Base Station Charging

To charge the base station, connect the USB (Type-C) cable (included in the yellow carrying case provided upon delivery) to the charging port as shown above. If needed, any USB Type-C cable connected to a PD 3.0 charger can also be used to charge the base station. This base station accepts any USB PD 3.0 charger and any other type of USB charger. It can be quick-charged with a maximum allowable power of 36W at 20V.

Note: A waterproof USB Type-A cable can be used for charging under wet or raining conditions, but the Type-A cable doesn’t support quick-charging. This method of charging will charge the battery with 12W power at 5V, and may take approximately 4-5 hours to fully charge the battery.

Battery Charging

The BURRO Generation 3 Base Station is installed with a 12V/5000mAh lithium-ion battery pack. This battery allows the unit to work continuously for over 24 hours on a single full charge, compatible with the new USB PD 3.0 specifications. The battery can be charged with the provided fast charger or any alternative USB charger. The maximum allowable charge power is 20V/36W. With 36W quick-charging, the battery can be fully charged within 2 hours. With 15W standard charging, the battery will take approximately 4-5 hours to obtain a full charge.

This lithium battery should last over 400 charge cycles, but in case of a potentially defective battery or constant over-use when the battery is too depleted, the battery may be replaced by opening up the battery cover and swapping it out with a new one. To replace the battery, remove the 4 M3 hex bolts on the battery cover using a M2 hex key. Open the cover after unscrewing the 4 M3 bolts and take the battery out by first disconnecting the connector from the battery cable wires to the base station. Then remove the old battery and connect the new battery to the connector inside the battery bay. Place the new battery inside the bay so the cover can close and re-install all 4 of the M3 hex bolts. Make sure the water seal is secure before tightening up the bolts. 

Troubleshooting

Base Station Issues

Base Wont Turn On

If the base does not turn on, then likely the Burros will not be able to operate on GPS. To check base power, please see if there is a green light on the base. 

• Turn off the base power and wait for the green light to turn off

• When the green light is back on, check to see if the Burros connected.

If it still does not turn on, or the Burros will not connect, please contact a field representative.