SPARK CORE – A DIY guide for KingMakers

http://www.spark.io

KANDARP JANI (janikd@hotmail.com)

DAN TEBBS

What is the Spark Core?

A Wi-Fi based module for connecting sensors, controllers and other gizmos to the Internet.

The Core includes the powerful STM32F103CB ARM 32-bit Cortex™-M3 CPU Core 72Mhz operating frequency, 1.25 DMIPS/MHz (Dhrystone 2.1) 128KB of Flash memory 20KB of SRAM 12 bit ADC USB 2.0 full-speed interface USART, SPI and I2C interfaces JTAG Debug mode

Spark Core Development is Arduino-like (gotcha is: most libs won't work without porting)o Small, low-cost, low-power computer that can run a single application.o Has a set of "pins" GPIO (General Purpose Input and Output) pins, both digital and analog.

D0 to D7 A0 to A7

o Supports Serial (also called UART), SPI, or I2C (also called Wire).

Has a Wi-Fi module, Uses “SmartConfig” to receive SSID & Password from the Spark Core Phone App

Connects it to your local Wi-Fi network using the SSID/Password

Establishes a connection to the Spark Cloud. (REST API)

Buttons

The RESET button

- Put the Core in a hard reset, effectively powering down and then re-powering the micro-controller

The MODE Button

- Smart Config mode

- Clear the Wifi-Network’s from Core’s memory

- Bootloader mode for flashing new firmware via USB

- Factory reset mode for bringing the core to original firmware

LEDs- The small blue LED is the user LED. It is connected to D7.

- The larger LED in the middle is a full-color RGB LED which always shows the status of the Core's Wi-Fi / internet connection.

The RGB LED states:

Flashing blue Listening mode, waiting for network information.

Solid blue Smart Config complete, network information found.

Flashing green Connecting to local Wi-Fi network.

Flashing cyan Connecting to Spark Cloud.

High-speed flashing cyan Spark Cloud handshake.

Slow breathing cyan Successfully connected to Spark Cloud.

Flashing magenta Updating firmware.

Pins

SETUP - Step 1 - Phone or Tablet

Setting up Spark on Phone

1. Go to the Google Play Store or iPhone apps

2. Search for “Spark Core”

a. https://play.google.com/store/apps/details?id=io.spark.core.android

3. Install the app.

4. Sign up for an account simply using an email address.

SETUP - Step 2 - Core1. Power the Core

2. Make sure it is blinking blue.a. If not - Hold down the MODE button until it starts blinking blue, then continue.

SETUP - Step 3 – WIFI / CLAIMING1. Make sure your phone is connected to the WiFi you want to use

2. Click on the wifi button in the app

3. SSID of the phone should show up on the app

4. Enter your password and

5. click CONNECT!

6. Be PATIENT , Observe the RGB LED on your core

7. If this works, you have now “claimed” this core and only your account has access to it.

This may take a little while- but be patient. It should go through the following colors:

The RGB LED states:

Flashing blue Listening mode, waiting for network information.

Solid blue Smart Config complete, network information found.

Flashing green Connecting to local Wi-Fi network.

Flashing cyan Connecting to Spark Cloud.

High-speed flashing cyan Spark Cloud handshake.

Slow breathing cyan Successfully connected to Spark Cloud.

Flashing magenta Updating firmware.

SETUP - Step 4 - The Tinker Screen

LETS TINKER

Blink an LED with Tinker

1. Tap D7

2. Then digitalWrite in the popup.

3. Then tap the D7 circle

The tiny blue LED should turn off and on.

SETUP - Step 5 - Web IDE

Go to Spark.io/build1. Sign in using the same user name ID (email) you used earlier.

See Your Core Via The Web

1. CLICK on the on the bottom left

2. CLICK on the > (GREATER THAN ICON)

3. Device ID: identifies the device uniquely

Blink Your LED via THE WEB

1. Click on the “CODE” ICON

2. Click "BLINK AN LED" under the Example apps title.

3. Brings up the familiar Arduino IDE like Code environment.

4. Click FORK THIS SAMPLE

FLASH THE FIRMWARE FROM THE CLOUD 1. Click on verify if you want to verify that the code compile s

2. Click on the flash button

3. Spark Cores should start flashing magenta, then more magenta, then green, then cyan (fast), then cyan (breathing)

Cloud Functions

REST API (Cloud API ) 1. Allows reading the value of a variable exposed in the spark firmware via the Cloud using

“HTTP GET”

GET /v1/devices/{DEVICE_ID}/{VARIABLE}.

2. Allows calling a function that you implement in the spark firmware via the Cloud using

“HTTP POST”

POST /v1/devices/{DEVICE_ID}/{FUNCTION}

Reading a variable from Spark Core via the Cloud

Step 1: Expose the Variable via Spark.variable()

Expose a variable through the Spark Cloud so that it can be called with:

// EXAMPLE USAGE

int analogvalue = 0;

double tempC = 0;

char *message = "my name is spark";

void setup()

{

// variable name max length is 12 characters long

Spark.variable("analogvalue", &analogvalue, INT);

Spark.variable("temp", &tempC, DOUBLE);

Spark.variable("mess", message, STRING);

pinMode(A0, INPUT);

}

void loop()

{

// Read the analog value of the sensor (TMP36)

analogvalue = analogRead(A0);

//Convert the reading into degree celcius

tempC = (((analogvalue * 3.3)/4095) - 0.5) * 100;

delay(200);

}

STEP 2: Get your API TOKEN.

STEP 3: Read from the Cloud OPTION 1: http://jflasher.github.io/spark-helper/

1. Enter your CORE ID

2. Enter your API Token

STEP 3: Read from the Cloud with CURL

OPTION 2: USE CURL

1. Download : http://curl.haxx.se/dlwiz/

2. Open cmd.exe on windows and run the following commands

# Core ID is 0123456789abcdef

# Your access token is 123412341234

curl "https://api.spark.io/v1/devices/0123456789abcdef/analogvalue?access_token=123412341234"

curl "https://api.spark.io/v1/devices/0123456789abcdef/temp?access_token=123412341234"

curl "https://api.spark.io/v1/devices/0123456789abcdef/mess?access_token=123412341234"

# In return you'll get something like this:

960

27.44322344322344

my name is spark

Calling a function on Spark Core via the Cloud

Spark.function()

Expose a function through the Spark Cloud so that it can be called with POST device/{FUNCTION}.

int brewCoffee(String command);

void setup()

{

// register the Spark function

Spark.function("brew", brewCoffee);

}

void loop()

{

// this loops forever

}

// this function automagically gets called upon a matching POST request

int brewCoffee(String command)

{

// look for the matching argument "coffee" <-- max of 64 characters long

if(command == "coffee")

{

// do something here

activateWaterHeater();

activateWaterPump();

return 1;

}

else return -1;

}

COMPLEMENTARY API CALL

POST /v1/devices/{DEVICE_ID}/{FUNCTION}

# EXAMPLE REQUEST

curl https://api.spark.io/v1/devices/0123456789abcdef/brew \

-d access_token=123412341234 \

-d "args=coffee"

Appendix – TroubleshootingWi-Fi Setup -

It needs to be blinking blue before attempting setup, but it is green or cyan:

Hold down the Mode Button for 10 sec.

The LED will change to blue.

The LED will do several quick flashes.

At this point it is ready for a Wi-Fi Setup attempt.

The core never progresses past the blinking green stage:

Did you select the right Wi-Fi network SSID?

Did you use the correct password for that network?

Is your phone/tablet device already connected to that network?

Claiming the Core -

The core is slow blinking cyan, but still doesn't show in the app:

This can happen if the core is already claimed on someone else's account.

Have that person sign in to the app, and release that core.

Then try again to claim the core from your own app and account.