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

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KC 01
KC01

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!! Description
It's highly recommended that you read the [AdaFruit Crickit|https://learn.adafruit.com/adafruit-crickit-creative-robotic-interactive-construction-kit] and the [Circuit Playground Express|https://learn.adafruit.com/adafruit-circuit-playground-express] guides so you can better understand their features, and how the Circuit Playground Express can be programmed.
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Here are the requirements for the robot: [{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'}]
[{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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* around NZ$100 if possible as a base price
Here are the requirements for the robot:
* around NZ$150 if possible as a base price
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* relatively easy to start
* provide an expandable base for further experimentation
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The combination of the Circuit Playground Express and the Crickit board for it provides:
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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.
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!! 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.
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Below is the Bill of Materials, with an estimated cost of __NZ$143__. This doesn't include miscellaneous
Below is the Bill of Materials, with an estimated cost of __NZ$147__. This doesn't include miscellaneous
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| 1x | 90mm x 90mm chassis plate (2-4mm thick wood or plastic: nylon, polycarbonate, Delrin or ) | NA | NZ$5
| 1x | USB battery | NA | NZ$25 (est)
| 1x | 90mm x 90mm chassis plate (2-4mm thick wood or plastic: nylon, polycarbonate, Delrin or ) | NA | NZ$5 | Macplas or Cactus Plastics
| 1x | USB battery | NA | NZ$25 (est) | anywhere
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|| Total | | | NZ$143
|| Total | | | __NZ$147__
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* Circuit Playground requires __exactly__ a 5 volt supply (AA/AAA batteries not suitable)
* what will we use for the free-wheeling caster?
* likely cannot handle transitions between carpet and floor, i.e., requires a smooth operating surface
* Circuit Playground requires __exactly__ a 5 volt supply (so AA/AAA batteries are not suitable)
* what will we use for the free-wheeling caster? It needs to be between 20-25mm total height.
* this robot is pretty small and likely cannot handle transitions between carpet and floor, i.e., requires a smooth operating surface
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[{Tag RobotPrototype}]
This page (revision-23) was last changed on 2021-04-30 11:40 by Murray AltheimTop