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SPACE CADETS

Robot Arm

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ELECTRONICS �&�CODING

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This motor controller can drive 16 servos!

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This is the brain - we will use it to control the motor driver and other interfaces.

Connect the brain to laptop for power - you should see the red LED turn on.

Reset Button

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Concept

Model

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First let’s make sure we can control the brain…

http://a9i.sg/ioty ��This is the coding environment

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FLASHING

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FLASHING - Setup Brain for IoTy

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Click on either Connect buttons and find an active, connected COM Port

If you don’t see a COM port in the window, check your brain is connected via USB and call the teacher!

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1.

2.

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Enter “ioty- <Student #>” assigned by coach

Before you press Flash, reset IoTy once - �click on left/EN/Reset button on Brain

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Each time you reset after you successfully flash, you should see Blue LED flash 3 times.

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Then will start to blink…

Reset Button

CONNECT TO PC

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BASIC CODING

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Press the 3 vertical dots, and choose “Connection Mode”. Inside, pick Serial.

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Press the 3 vertical dots, and choose “Connect (Serial)”. Choose COM port of brain.

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Let’s see if we are connected�Switch to Monitor tab, and reset Brain

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You should see this. Almost…

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In a bit we will type some python instructions.

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First, let’s write the block code to get an idea…

Pin 2 - controls Blue LED

1 means ON

0 means OFF

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Download to Device…

Reset Device…

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Now paste the last line and hit ENTER -

This should turn on Pin 2 on the brain.

You should see the blue LED turn on!

Can you figure out what to type to turn it off?

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MOTOR CONTROLLER

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Brain

Motor Controller

3V3

VCC

VIN

V+

GND

GND

D18

SCL

D19

SDA

CONNECTIONS

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Now let’s write the code that sets up the motor controller system.

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Now let’s write the code that sets up the motor controller system.

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Blocks from I2C and PCA-9685 block tabs

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Blocks from I2C and PCA-9685 block tabs

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And use these instructions to test Robot Arm:

pca9685_device.servo_deg(Ch, Degrees)

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Ch = 0, 2, 4 or 6

Degrees = 0 to 180

Connect each of the 4 servos to a channel:

0(base), 2(left), 4(right), 6(claw)

Make sure not to stress motors to impossible positions!

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ROBOT ARM�CHALLENGES

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How hard is it to use coding instructions to:

  • Move Arm from Side to Side 10 times

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  • Move Arm to 1 Position, and open claw
  • Move Arm to 2nd Position, and close claw