Sparkfun Gator:bit v2 Technical document

SparkFun gator:bit v2 Hookup Guide

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Introduction

The SparkFun gator:bit v2 is a development board for the BBC micro:bit. Almost every pad of the micro:bit is

broken out to alligator clippable pads, on the gator:bit, so you can get the most out of it. The gator:bit comes

equipped with five addressable LEDs, a built-in buzzer (speaker), as well as a power management system that

gives you access to 3.3V and 5V. The gator:bit can be powered from 2.7V - 9V giving you quite a range of

powering options.

SparkFun gator:bit v2.0 - micro:bit Carrier Board

 DEV-15162

Product Showcase: SparkFun gator:bit v2.0Product Showcase: SparkFun gator:bit v2.0Product Showcase: SparkFun gator:bit v2.0

gator:bit v2 Hookup Guide Wishlist SparkFun Wish List

Without any external hardware, the gator:bit (v2) is still an exploratory development board for micro:bit. Whether it

is data visualization using the on board addressable LEDs or creating musical works of art using the built-in

speaker we’ve got it covered with the with the gator:bit.

With some alligator clips and extra hardware you’ll be able to explore inputs like sensors, potentiometers, and

buttons and control outputs like lights, motors, and speakers.

Required Materials

Here are some products that will help you get started with the gator:bit:

SparkFun gator:bit v2.0 - micro:bit Carrier Board

DEV-15162

micro:bit Board

DEV-14208

The BBC micro:bit is a pocket-sized computer that lets you get creative with digital technology. Each order contains…

USB Micro-B Cable - 6"

CAB-13244

This is a USB 2.0 type B to Micro-B 5-pin black cable. You know, the mini-B connector that usually comes with cell …

Battery Holder - 4xAA to Barrel Jack Connector

PRT-09835

This is a simple 4 cell AA battery holder. The 5 inch cable is terminated with a standard 5.5x2.1mm, center positive …

Suggested Materials

In addition to the above, here are some products to get you started with building circuits to control inputs and

outputs using the gator:bit:

SparkFun gator:starter ProtoSnap

 SEN-14891

SparkFun gator:color ProtoSnap

 COM-14890

CLICK TO SEE MORE COMPONENTS!

Suggested Reading

If you aren’t familiar with the following concepts, we recommend checking out these tutorials before continuing.

Hardware Overview

SparkFun gator:control ProtoSnap

 COM-14968

Alligator Test Leads - Multicolored (10 Pack)

 PRT-12978

What is a Circuit?

Every electrical project starts with a circuit. Don't know

what a circuit is? We're here to help.

Voltage, Current, Resistance, and Ohm's Law

Learn about Ohm's Law, one of the most fundamental

equations in all electrical engineering.

What is Electricity?

We can see electricity in action on our computers,

lighting our houses, as lightning strikes in

thunderstorms, but what is it? This is not an easy

question, but this tutorial will shed some light on it!

Light-Emitting Diodes (LEDs)

Learn the basics about LEDs as well as some more

advanced topics to help you calculate requirements for

projects containing many LEDs.

Features:

micro:bit card edge connector

Barrel Jack (5.5 x 2.1mm)

Input voltage: 2.7V - 9V

5 built in addressable LEDs

Built in buzzer

5V output

3.3V output

7 protected input/output pins

3 pins for SPI communication

2 pins for I C

Powering Your gator:bit

There are 3 ways of powering your gator:bit v2, either from the barrel jack, the alligator clippable pads labeled

VIN, or through the micro:bit itself. On the gator:bit, any input voltage between 2.7V and 9V will be regulated to

3.3V to power the micro:bit, the speaker, and for use by any of the alligator clippable pins. 5V is also regulated or

boosted from the input voltage to power the LEDs and any off-board hardware you would like to use like servo

motors. When the gator:bit is powered, the power indication LED, highlighted in red below, will turn on.

Whether you are providing power from either the barrel jack or from a clipped source, the gator:bit can be used

with a USB on the micro:bit. The power circuitry for the gator:bit is arranged so that the board uses the largest

power source.

Power options. Power indication LED highlighted in red.

Input Pins

I/O Protected Pins

The point of gator:bit (v2) is to give you access to as much GPIO as possible from the micro:bit, safely. Not only

are pins 0, 1, 2, 8, 16, 5 (Button A), and 11 (Button B) broken out, but they are also protected against overvoltage

and overcurrent/short circuit. Pins 0, 1, and 2 are ADC pins; while, pins 8, 16, 5, and 11 are digital pins capable of

read and write.

Note: Due to the protection diodes, the capacitive sense functionality of pins 0, 1, and 2 may be limited, if not

non-existent.

Input pins.

I2C and SPI Serial

The gator:bit also provides access to pins 13, 14, 15, 19 & 20. These are digital pins that can be used to read and

write digital signals. Pins 13, 14, & 15 are also SPI communication pins giving you the ability to use SparkFun’s

SPI sensors with the gator:bit. Pins 19 & 20 are I C communication pins which extend the use of the micro:bit to

include all of SparkFun’s I C sensors.

Read/Write digital ports.

Outputs

Voltage Output

The gator:bit (v2) gives you access to more micro:bit pins and it also gives you access to 3.3V and 5V. Your servo

action is about to get a little cleaner and you’ll be able to easily power peripheral hardware.

In order to use the voltage out tabs, the VOUT switch needs to be switched on. Having the option to turn it off is

great when when you don’t need it.

VOUT switch.

On the right side of the board there are two “OUT” pins. One for 5V and one for 3.3V. You will know when the

output voltage is available because two red LEDs will turn on right above the pad. You can use either of the two

ground pads since all ground is connected.

VOUT Ports.

Now let’s look at the fun kind of output, light and sound! On the bottom left is a buzzer. We chose a small speaker

on purpose. You’ll be able to explore creating digital music and then listen to it right on the gator:bit. You can easily

attach a larger speaker when you are ready to show off your work.

Piezo Speaker

You’ll notice another switch here. The speaker is attached to pin 0, so if you want to play music the music switch

needs to be on and you won’t be able to use pin 0. Conversely, if you want to use pin 0, the music switch needs to

be switched off.

Speaker and music switch.

Addressable LEDs

LEDs! Addressable LEDs! Connected to pin 12 are 5 addressable LEDs with the first LED on the left. The

Neopixel MakeCode extension is an excellent way to control these. We have a few examples using the extension

coming up.

LEDs!

Programming Environments

There are several programming environments to use your micro:bit and gator:bit with.

MakeCode

Makecode is a web application based on block programming. The blocks then directly convert to Javascript; you

can switch back and forth for ease of inspection. To upload your program to the micro:bit you download the project

and drag and drop it on the micro:bit.

A quick start guide on MakeCode is the best way to become familiar with blocks, extensions, downloading and

running programs on the micro:bit.

GET STARTED WITH MAKECODE!

From the start you are presented with the basic building blocks on a program. on start is where your setup is,

variable declarations, and any other start up messages or images. forever is your looping function. If you want to

blink an LED you’d turn an LED on for some amount of time and off for some amount of time the loop would allow

that to repeat forever.