This page (revision-23) was last changed on 2021-04-30 11:40 by Murray Altheim

This page was created on 2019-12-28 03:23 by Murray Altheim

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Version Date Modified Size Author Changes ... Change note
23 2021-04-30 11:40 10 KB Murray Altheim to previous
22 2021-04-30 11:39 10 KB Murray Altheim to previous | to last
21 2021-04-30 11:31 10 KB Murray Altheim to previous | to last

Page References

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KC 01
KC01

Version management

Difference between version and

At line 18 removed 2 lines
[{Image src='attach/KC01/crickit-circuit-playground-thumb.jpg' link='attach/KC01/crickit-circuit-playground.jpg' caption='Crickit for Circuit Playground' align='right' class='imgFloatRight'}]
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* small and lightweight so that it can be run using a pair of micro gear motors
* small and lightweight (''[mini robot|MiniRobot]'' class) so that it can be run using a pair of micro gear motors
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* relatively easy to start
* relatively easy to build and program
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The combination of the Circuit Playground Express and the Crickit board for it provides:
!! Features
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* a microcontroller than can be programmed in [CircuitPython] (a subset of [Python])
* two motor controllers
* four servo controllers
* four channels of 5 volt drivers
* a ring of programmable RGB LEDs on the CircuitPlayground
* a NeoPixel driver (for control of strings of coloured LEDs)
* a small speaker with a 3 watt audio amplifier (!)
* four capacitive touch sensors
* 8 channels of digital I/O or analog inputs
* safety features: the Crickit has kick-back diode protection on the motors and its power supply has an 'eFuse' management chip that turns everything off if the supply power is greater than 5.5V or less than 3V.
[{Image src='attach/KC01/crickit-circuit-playground-thumb.jpg' link='attach/KC01/crickit-circuit-playground.jpg' caption='Crickit for Circuit Playground' align='right' class='imgFloatRight'}]
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!! Upgrades
The Circuit Playground Express provides:
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* 10 x mini NeoPixels, each one can display any color
* 1 x Motion sensor (LIS3DH triple-axis accelerometer with tap detection, free-fall detection)
* 1 x Temperature sensor (thermistor)
* 1 x Light sensor (phototransistor). Can also act as a color sensor and pulse sensor.
* 1 x Sound sensor (MEMS microphone)
* 1 x Mini speaker with class D amplifier (7.5mm magnetic speaker/buzzer)
* 2 x Push buttons, labeled A and B
* 1 x Slide switch
* Infrared receiver and transmitter - can receive and transmit any remote control codes, as well as send messages between Circuit Playground Expresses. Can also act as a proximity sensor.
* 8 x alligator-clip friendly input/output pins
* Includes I2C, UART, 8 pins that can do analog inputs, multiple PWM output
* 7 pads can act as capacitive touch inputs and the 1 remaining is a true analog output
* Green "ON" LED so you know its powered
* Red "#13" LED for basic blinking
* Reset button
* ATSAMD21 ARM Cortex M0 Processor, running at 3.3V and 48MHz
* 2 MB of SPI Flash storage, used primarily with [CircuitPython] to store code and libraries
* MicroUSB port for programming and debugging
* USB port can act like serial port, keyboard, mouse, joystick or MIDI!
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If you want to use odometry, you can __upgrade__ by buying the motor encoders and the motors ''without'' the Push Header Shim (which is incompatible with the motor encoders as they both solder to the same place). You'll want the extended back shaft version.
The Crickit board provides:
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* [Magnetic Encoder Pair Kit for Micro Metal Gearmotors, 12 CPR, 2.7-18V (HPCB compatible)
|https://shop.pimoroni.com/products/magnetic-encoder-pair-kit-for-micro-metal-gearmotors-12-cpr-2-7-18v-hpcb-compatible]
* [Micro Metal Gearmotor (Extended back shaft) – 298:1
|https://shop.pimoroni.com/products/micro-metal-gearmotor-extended-back-shaft?variant=3073681089]
* 4x Analog or Digital Servo control, with precision 16-bit timers
* 2x Bi-directional brushed DC motor control, 1 Amp current limited each, with 8-bit PWM speed control (or one stepper)
* 4x High current "Darlington" 500mA drive outputs with kick-back diode protection. For solenoids, relays, large LEDs, or one uni-polar stepper
* 4x Capacitive touch sensors with alligator-pads
* 8x Signal pins, digital in/out or analog inputs
* 1x NeoPixel driver with 5V level shifter
* 1x Class D, 4-8 ohm speaker, 3W-max audio amplifier
At line 54 removed one line
There are a variety of gear ratios available: 11:1, 20:1, 50:1, 298:1 and 1006:1. This will effect both the upper speed of the motor and its torque (power). I chose the 298:1 because I want my robot to be a bit slower and stronger. The 50:1 might work but if you have to reduce the power sent to the motor in order to get it to drive slow enough, it won't have much torque. The choice of gear ratio is always a __compromise__.
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Other upgrades include adding sensors and IO devices to any of the above-listed connections on the Crickit board.
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|| Total | | | __NZ$147__
| 1x | [Moon Buggy Wheels - Pair|https://shop.pimoroni.com/products/moon-buggy-wheels-pair] | £4.50 | NZ$8.77 | Pimoroni
|| Total | | | __NZ$156__
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!! Options
* AdaFruit sell some nice [90:1 gearbox motors|https://www.adafruit.com/product/3802] for US$5.95
* there are many options for wheels - just be sure you get some that match the 3mm shafts of whatever motors you choose
!! Upgrades
If you want to use odometry, you can __upgrade__ by buying the motor encoders and the motors ''without'' the Push Header Shim (which is incompatible with the motor encoders as they both solder to the same place). You'll want the extended back shaft version.
* [Magnetic Encoder Pair Kit for Micro Metal Gearmotors, 12 CPR, 2.7-18V (HPCB compatible)
|https://shop.pimoroni.com/products/magnetic-encoder-pair-kit-for-micro-metal-gearmotors-12-cpr-2-7-18v-hpcb-compatible]
* [Micro Metal Gearmotor (Extended back shaft) – 298:1
|https://shop.pimoroni.com/products/micro-metal-gearmotor-extended-back-shaft?variant=3073681089]
There are a variety of gear ratios available: 11:1, 20:1, 50:1, 298:1 and 1006:1. This will effect both the upper speed of the motor and its torque (power). I chose the 298:1 because I want my robot to be a bit slower and stronger. The 50:1 might work but if you have to reduce the power sent to the motor in order to get it to drive slow enough, it won't have much torque. The choice of gear ratio is always a __compromise__.
Other upgrades include adding sensors and IO devices to any of the above-listed connections on the Crickit board.
This page (revision-23) was last changed on 2021-04-30 11:40 by Murray AltheimTop