Robot Project 2021 Notes

(BBC micro:bit + Sparkfun moto:bit)

Sparkfun moto:bit Carrier Board

The moto:bit - micro:bit Carrier Board (Qwiic) uses a Qwiic interface? and offers pins for:

• six 3-pin sensors,
• two 3-pin servo motors
• two 2-pin “big” motors

and an I2C bus (as well as a Qwiic “port” and power switch)

       +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                              micro:bit CONNECTOR BUS


           ANALOG           DIGITAL
           DIGITAL            ONLY
              |                |
       +-+----+-------+ +------+------+-+
       | |            | |             | |                           SCL  ☐
    P0 • •  P1     P2 • • P8      P12 • • P14      P15 • • P16      SDA  ☐
   3V3 • • 3V3    3V3 • • 3V3     3V3 • • 3V3      VCC • • VCC      3V3  ☐
   GND • • GND    GND • • GND     GND • • GND      GND • • GND      GND  ☐

      SENSOR         SENSOR          SENSOR           SERVO         I2C BUS



        BLACK •   LEFT                           RIGHT  • RED
        RED   •   MOTOR                          MOTOR  • BLACK


   POWER IN
  INPUT RANGE
  VCC: 3 - 11V                                                  QWIIC


                  STOP                RUN
                 MOTORS              MOTORS

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Wheel Motor Assembly

• Geez! They weren’t kidding! Getting the front motor mounts over the big motors was a PITA! Ultimately, brute forcing it with my hand rather than pliers proved the most successful.
• The rear motor mounts were only slightly better.
• Mounting the assemblage to the bottom chassis, I was sure I was going to snap something in two or tear out a wire.
• The motor I’ve mounted on the right side has a black wire whose solder point looks suspect…

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Line folowing sensors

• The pins should be sticking out on the smooth side of the “bottom” mount.
• By contrast, this slipped together so easily that I worry it might be too loose, though it will undoubtedly tighten up when mounted to the chassis.
• This tutorial seems to be a thinly disguised advertisment for electrical tape…

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Chassis

• 10-year-olds my ass. This required a hell of a lot of strength to snap the chassis together without snapping.
• Don’t forget: there are eight snap points: Four at the corners and two above the wheels. I got the outer four, and didn’t notice the wheel ones until after the fact. It took forever to get those to snap into place.

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