MR-B3RB-M ("Medium/Main")

The following pages describe the mechanical assembly of the MR-B3RB-M version. The -M version of MR-B3RB includes the -MUK mechanical upgrade kit consisting of:

• Front and rear plastics (for LED covers and angles front and rear covers)

• Lidar arch plate metal and metal top cover.

To install the -MUK (Mechanical Upgrade kit) you will need to first:

• Remove the plastic clips that hold the top metal plate in place and

• Replace them with the side skirt plastic.

• Then install the front and rear plastics as shown in the following assembly videos.

• (This will change in production version. Side skirts will already be present in base version)

MR-B3RB-S ("Small/Standard" Pre Production)

You may have a -S version of the kit which doesn't include these extra components, in that case just mount the NavQPlus and MR-CANHUBK344 in a similar way as shown in the assembly videos.

There is a plastic bracket included with the NavQPlus kit that can be used to mount the camera in the correct location at the front.

Now mount the NavQPlus and the MR-CANHUBK344 to the metal top plate. Follow the steps in the next two sections. The final setup will look like this:

The gears are adjusted at the factory and this should not need to be done on a new B3RB. However over time it may be that they need adjustment. Follow this procedure to re-adjust the gear meshing. Diagnose Motor Gear Meshing Issue

1. Rotate the Wheels Gently: Start by gently rotating the wheels of the B3RB that the motor is driving.

2. Listen Carefully: Listen to the sound of the gears as you rotate the wheels. Ideally, the gears should mesh smoothly without any grinding or excessive noise.

3. Feel for Resistance: As you rotate the wheels, feel for any resistance or unevenness. This could indicate that the gears are not meshing properly.

Adjust the Gear Mesh

1. Locate the Motor Mounting Bracket: Identify the motor mounting bracket where the motor is attached to the chassis or frame of your device.

2. Loosen the Adjustment Screws: Typically, there are two screws at the front of the motor mounting bracket that secure the motor in place. Use an appropriate screwdriver to gently loosen these screws. You don’t need to remove them completely, just enough to allow slight movement of the motor.

3. Adjust the Motor Position: Apply mild pressure to the motor in the direction that will improve the gear meshing. This usually means pushing the motor closer to the gear or slightly adjusting its angle to ensure the teeth of the gears are aligned properly.

4. Check and Tighten: After adjusting, rotate the wheels again and listen for any improvement in the gear meshing. Once satisfied with the adjustment, carefully tighten the screws back into place to secure the motor in its adjusted position.

First chose option A or B

Option A: Dual Lock mounting the NavQPlus on the metal frame

Option B: Mounting the NavQPlus on the metal frame

Alternative mounting using screws

The kit includes DUAL LOCK type mounting, eliminating the need for the procedure below and screw fastening. This will also elevate the NAVQPLUS boards slightly so that Ethernet and USB will have better clearance. We strongly recommend you just use some DUAL LOCK Velcro instead of screwing the NavQPlus to the metal frame.

An alternative method of mounting is to use the provided M3 screws to securely attach the board's corners to the following position in the metal frame:

Screw them in from the bottom side. It should look like this:

Then wire the cables: NavQPlus Cable management on top plate

Use a ziptie to secure the power cable (4 wire cable with 5 pin JST-GH), and route the CAN cables down and underneath as shown below.

After successfully attaching the NavQPlus, the next step is to install the MR-CANHUBK344 evaluation board.

MR-B3RB-M

The lower chassis comes partially assembled with the side skirts attached, the side plastic attached, the PDB partially wired, and the LED lighting installed and wired. Remove screws that hold on the side plates and also the screws that hold on the top plate. The screws holding the side skirts and top plate on top will be replaced with Thumbscrews . KEEP these M3x5mm screws for attaching the MR-CANHUBK344 to the top plate later

Lower chassis out of the box.

Remove top plate screws

Use a hex screwdriver or Allen Key and remove all top screws securing the top plate to the metal frame and carefully set them aside.

Introduction

MR-CANHUBK344 is the real time controller board for the robot. After successfully attaching the NavQPlus, the next step is to install the MR-CANHUBK344 evaluation board.

Assemble MR-CANHUBK344 onto top plate

The MR-CANHUBK344 board should be attached in the highlighted holes of the following image. Reuse the M3x5mm screws that were previously removed from the side skirts. M3x5mm screws should be used to screw in from the bottom side.

Be cautious to not squeeze the wires attached to the NavQPlus!

Upon completion, the entire assembly should appear as follows:

Standoff for LIDAR arch stability

There is a orange or black 3d printed plastic standoff post which also acts to protect the cable. The file will also be provided in 3D Printed parts page See image below

Attach the NavQPlus camera to the front plastic mount.

The camera housing included with the NavQPlus mounts to the front "GoPro" style mount on the front plastic:

You must use the screw and bolt that included along with the original camera mount. (This is from the white plastic mount included with the NavQPlus)

The camera flex cable should come out the back of the NavQPlus and loop over top of it. Then route under the lower edge of the front bracket. and up into the camera module. The final setup should look like this:

Front and rear plastic

Screw the front and rear plastic to the top plate using two M3x5 screws from the bottom

The camera flex cable should already be attached to the front plastic.

Wiring instructions will be demonstrated using images and GIFs for clearer visualization of the process.

Introduction

The RGB LEDS communicate using a modified SPI type that is unidirectional. The power for the LEDs is supplied by the PDB, and the SCL SDA lines attach to a SPI port on the MR-CANHUBK344

RGB LED wiring

First, we'll show hot to connect the LEDs cables from the LEDs panels to the PDB and the MR-CANHUBK344.

• Use the 4-pin cable with a protective covering to connect from the front to the rear LED assembly ends.

• Connect the rear LED to the PDB (Power Distribution Board) and the MR-CANHUBK344.

The following image shows the LED lights setup with the left side representing the rear and the right side indicating the front of the car.

The following images show a zoomed vision of the wiring:

The remaining pin is this one:

That must be connected on the following pin of the MR-CANHUBK344:

If you have correctly followed these steps the wiring setup of the LEDs cables should be finished.

Introduction

The kit may include an ARMING board and/or a GPS module. In addition to being used for GPS, the it does also include a arming/safety switch and a beeper. Generally if you have a GPS, it is preferred to use that rather than the ARMING board.

PX4 Arming Board vs GPS

The arming board will provide the same beeper and arming buttons. It does not (currently) include a compass component.

Install M10 GPS module

If provided in your kit, please install the GPS and GPS post mounting, The the pieces needed are listed in the page.

There is a set of screws that comes with the GPS unit. Use the 4 longer screws and Nylock Lock Nuts to attach the base mount.

It should be placed in this furthest back position:

Attach the mounting mast rod and fasten it with one of the smaller two screws left. At this time keep the screws only loosely tightened. Attach the top mount with the remaining screw. Keep it only loosely tighened as well. It should look like this when completed:

Attach the M10 GPS module to the mast

Locate the M10 GPS and the 3M double tape.

Attach the double tape in the center of the top mount.

Carefully align the GPS in the center of this tape. Ensure the arrow on the GPS module is facing forward. The cable of the GPS should be zip tied so it stays very close to the GPS mast in order to not obstruct the LIDAR sensor.

The MR-B3RB is versatile and can support several network wiring configurations. There are also several optional connections. This section will serve to show the BASELINE connections. We will also attach cables that may not be used, but should stay with the B3RB for future expansion

Baseline wiring intentions

• Provide power to the NavQPlus and MR-CANHUBK344

• Connect the two with T1 Ethernet

• Attach the LIDAR to the NavQPlus

• Attach the SERVO and Motor Control PWM to the MR-CANHUBK344

• Quadrature encoding from the motor/PDB to the MR-CANHUBK344

• Connect the RGB LED lighting

• Have debuggers and consoles attached

• Optionally plug in unused RC-PWM input

• Optionally connect CAN-FD cables, which could be used for peripherals and attachments

• (Optionally) connect a serial console from the MR-CANHUBK344 to the NavQPlus <<TODO - add link to section that removes the jumper on the PDB. Add PDB wiring section>>>

The final setup with al the established connections should look like this: <<<TODO UPDATE PHOTOS FROM HERE ON >>>

A closer view on the connection on MR-CANHUBK344:

And in the NavQPlus:

Please follow the steps 3a and 3b for the detailed explanation on these connections.

Introduction

The Quadrature decoder (QDEC) cable connects from PDB to MR-CANHUBK344. The actual quadrature signals are coming from the encoder on the motor itself. The PDB is used to interface between the different cable types. This signal provides information on how many revolutions, and therefore how far, the robot has travelled and is used in the control system as an input.

QDEC (Quadrature Decoder) Cable

This cable is crucial for calculating the odometry, speed and direction of the robot car. The cable should look like this:

One end of the cable must be attached to the QDEC out pin on the PDB:

And the other end must be attached to the following pin on the MR-CANHUBK344:

Introduction

There are two 5 pin JST-GH cables that provide battery power to the MR-CANHUBK344 and the NavQPlus. They are 5 pins, with no wire in the center position. Two wires are battery voltage+ and two wires are battery voltage-. Be sure to limit the voltage applied at the battery to <20V or the specified ratings for any boards plugged in. The nominal battery voltage is expected to be ~12V,

Power cable from PDB to MR-CANHUBK344

• Connect is the EXTRA LONG power cable from the MR-CANHUBK344 to the Power Distribution Board.

• The normal length power cable can be similarly connected to the NavQPlus

• ZIP TIE the cables to the edge of the top plate and make them neat.

These cable connect to the 5 pin JST GH on the PDB. Either connector is ok. They are both the same.

And the other end must be connected to this pin on the MR-CANHUBK344

The following picture depicts the connections in an animated way.

M10 GPS connection

This is the M10 GPS

And this is all the cable connections available for now.

Introduction

The MR-CANHUBK344 sends PWM signals to the Motor controller and also to the Servo. These are standard RC Model type PWM connections. It is important to get the positions correct on the header as the PWM signal timings are different between the motor and the steering servo. Also note that the steering servo gets powered from the +5V that is PROVIDED by the motor PWB connection on the PDB board.

PWM cable wiring to MR-CANHUBK344

The PWM cables that connect between the MR-CANHUBK344 board and the Power Distribution Board should look like this. Two of them are Female-Female and one is Male-Female.

Servo cable color code

Note that an extension cable is used for the servo PWM. The cable on the servo changes to the the alternative coloring as shown in the table below.

The cable color coding is as follows:

EXTRA CARE NEEDED

The PWM cable must be oriented so that the white signal wire is connection the pin labelled (S) on the MR-CANHUBK344.

The wite wire should be "inboard" on the PCB. The black ground wire will be closest to the outboard edge of the PCB.

Steering Servo PWM cable connection

The PWM cable that connects to the servo must be connected to PWM 0 of the MR-CANHUBK344. This is the PWM header CLOSEST to the side of the board with the CAN connectors.

This is depicted in the following GIF:

Motor control PWM cable connection

<<TODO>> make it more clear which cable is which. There is also a debug procedure that can be added. IF the motor starts running immediately on power up, then PWM 1 and PWM 2 need to be swapped. Confirm - This is when only ONE of the PWMs are connected.

The PWM cables that correspond to the motor throttle (PWM 1) and motor ENB (PWM2) must be connected on the following pins on the PDB:

The other end of the cables must be located in PWM 1 and PWM 2 positions of the MR-CANHUBK344:

The following GIF shows the connection of the three cables:

Power cable from PDB to MR-CANHUBK344

The last cable to connect is the EXTRA LONG power cable from the MR-CANHUBK344 to the Power Distribution Board which looks like this. The normal length power cable can be similarly connected to the NavQPlus

This is how it must be connected to the PDB:

And the other end must be connected to this pin on the MR-CANHUBK344

The following picture depicts the connections in an animated way.

M10 GPS connection

This is the M10 GPS

And this is all the cable connections available for now.

Introduction

The GPS module is primarily used to provide the Magnetometer, sound and SAFETY button for the system. Not all systems will use the GPS localization functionality. The software however does injest the data and can be used for navigation outdoors.

M10 GPS connection

The M10 GPS cable attaches to the MR-CANHUBK344 as shown below

Wiring instructions will be demonstrated using images and GIFs for clearer visualization of the process.

RGB LED wiring

First, we'll show hot to connect the LEDs cables from the LEDs panels to the PDB and the MR-CANHUBK344.

• Use the 4-pin cable with a protective covering to connect from the front to the rear LED assembly ends.

• Connect the rear LED to the PDB (Power Distribution Board) and the MR-CANHUBK344.

The following image shows the LED lights setup with the left side representing the rear and the right side indicating the front of the car.

The following images show a zoomed vision of the wiring:

The remaining pin is this one:

That must be connected on the following pin of the MR-CANHUBK344:

If you have correctly followed these steps the wiring setup of the LEDs cables should be finished.

QDEC (Quadrature Decoder) Cable

This cable is crutial for calculating the odometry, speed and direction of the robot car. The cable should look like this:

One end of the cable must be attached to the QDEC out pin on the PDB:

And the other end must be attached to the following pin on the MR-CANHUBK344:

BaseT1 Ethernet wiring between NavQPlus and MR-CANHUBK344

Second, we'll show how to connect the ethernet cable between the NavQPlus and the MR-CANHUBK344.

PWM cable wiring to MR-CANHUBK344

The PWM cables that come from the MR-CANHUBK344 board to the Power Distribution Board should look like this.

Servo cable color code

The cable color code is as follows:

Ensure the cable is oriented so that the white PWM signal is connection the port labelled (S) on the MR-CANHUBK344. This is "inboard" on the PCB. The black ground wire will be closest to the outboard edge of the PCB.

The PWM cable that connects to the servo must be connected to PWM0 of the MR-CANHUBK344 as depicted in the following GIF:

The PWM cables that correspond to the motor throttle (PWM 1) and motor ENB (PWM2) must be connected on the following pins on the PDB:

The other end of the cables must be located in this position of the MR-CANHUBK344:

The following GIF shows the connection of the three cables:

Note that an extension cable is used for the servo PWM. The cable on the servo is the alternative coloring as shown in the table above.

Power cable from PDB to MR-CANHUBK344

The last cable to connect is the EXTRA LONG power cable from the MR-CANHUBK344 to the Power Distribution Board which looks like this. The normal length power cable can be similarly connected to the NavQPlus

This is how it must be connected to the PDB:

And the other end must be connected to this pin on the MR-CANHUBK344

The following picture depicts the connections in an animated way.

M10 GPS connection

This is the M10 GPS

And this is all the cable connections available for now.

Power Cable

The cable shown below is NOT USED in B3RB. Instead connect the 5 pin power cable to the corresponding point on the PDB

Connect the l5 pin (4 wire) JST-GH power cable to the NavQPlus Power input:

BaseT1 Ethernet wiring between NavQPlus and MR-CANHUBK344

This is also explained here: #baset1-ethernet-wiring-between-navqplus-and-mr-canhubk344

Lidar connection

<TODO> refer to the mounting of the LIDAR base

The cable necessary for connect the NavQPus to the LIDAR-STL-27 is the number one in WITB Cables and Screws.

A closer view of this cable:

The Lidar used is the following:

You should connect the smaller end of the cable to the Lidar and the bigger end to the UART3 Serial port of the NavQPlus:

Thse are all the connections available for NavQPlus:

<TODO >

• note on CAN

• note on console

• note on Ethernet

The top cover doubles as a work stand. This will keep the wheels up of the gound and can be useful while testing. You may want to put some soft tape or foam on the underside of the buggy chassis in order to avoid possible scratches on the top cover.

(DRAFT)

Block Diagram of the NavQPlus

<todo> insert a block diagram and or photo of wiring. Image below may be helpful

Prepare: Lidar mounted to metal LIDAR Arch

The screws below and nylon locking nuts are included in the LIDAR box. Use these to attach the LIDAR to the LIDAR Arch.

Connect LIDAR cable to NavQPlus UART

Attach the arch metal upper plate and the Lidar with 4 of the screws M3 X 0.5 X 10MM with socket head, labelled with (6) in the following picture:

The connection to the NavQPlus is shown above, and also explained in #lidar-connection

<<<TODO - move the lidar connection link details to this single page. Delete the other references>>

After connecting all the cables, proceed to attach the metal board frame to the robot car using the screws you removed at the beginning of this tutorial:

Front Plastic Shield with Mount for Camera

Please attach the plastic shield with the camera housing to the robot's front using 1cm M2.5 screws, which are located in this box provided:#m2-m2.5-m3-screw-fastener-kit-for-wltoys-144001-1-14-rc-s.no.-25.

For reference, a picture of the screws is displayed here: <<<TODO - these are not the correct screws. They should be flat head (tapered head> screws. Take picture and add here>>>

The mounting must look like these pictures:

Back Plastic Shield

And the attach the back plastic shield of the robot with the same screws:

Lidar arch metal upper plate

<<<<TODO - update the pictures below. The orientation of the LIDAR is backward!!!>>>

Attach the arch metal upper plate and the Lidar with 4 of the screws M3 X 0.5 X 10MM with socket head, labelled with the number six in the following picture:

It should look like this:

And the connection to the NavQPlus, as explained in #lidar-connection is depicted in this image:

Decorative top cover

METAL UPPER

LIDAR,

FINAL TOUCHES AND STICKERS

Introduction

The NavQPlus and MR-CANHUBK344 communicate to each other using 100Base-T1 Two wire ethernet .

BaseT1 Ethernet wiring between NavQPlus and MR-CANHUBK344

• Connect the ethernet cable between the NavQPlus and the MR-CANHUBK344.

• Zip Tie the cable at both ends, and tuck it under the top plate.

• Note the specific side notches to use.

• Use a piece of tape to hold it neatly out of the way under the plate