CY8CKIT-021: Example 10 — The iOS App

Now that we have completely tested PRoC and PSoC4200M firmware the next step is to build an iOS App called Example 10.  The Xcode project is available in the Xcode directory in the project directory at

Ill try to build this App to be as simple as possible.   Here is what the (single) screen looks like in three different state (nothing pressed, button0 pressed, led0 on):

IMG_0027     IMG_0028    IMG_0029

This App is built up with four files

  1. ViewController.swift: an object which controls the screen (button clicks)
  2. BluetoothNeighborhood.swift: an object which controls the Bluetooth in the phone and represents the CY8CKIT021 board (the Model)
  3. globals.swift: Defines the NSNotifications that can be sent
  4. Main.storyboard: The screen layout

The code will do the following:

  1. When the ViewController (VC) starts it will instantiate a BluetoothNeighborhood (BN) object
  2. VC: Tell the BN to start the bluetooth central in the phone
  3. BN: Scan for BLE Peripherals that are advertising the CY8CKIT-021 Service UUID
  4. BN: When it hears the peripheral with the correct UUID then connect
  5. BN: Read the state of the button0 and led0 then send an NSNotification
  6. BN: Turn on the notify for button0 (to cause the PRoC to send an NSNotification when there are changes)
  7. VC: update the screen when it gets the NSNotification from (5)
  8. VC: If the LED0 switch on the screen is switched then tell the BN to write to the PRoC
  9. BN: If the button0 is changed then send an NSNotification to the VC
  10. VC: If there is an NSNotification (9) of a button0 change then update the screen
  11. VC: If the bootloader button is pressed tell the BN to write the bootloader characteristic
  12. BN: If there is a disconnect event then send an NSNotification to the VC to disable the GUI elements and start scanning again (step 3)


The viewDidLoad method runs when the Apps starts and loads the first screen.  This method

  1. Initializes the BluetoothNeighborhood object
  2. Tell it to start the bluetooth scanning
  3. Disables the UI buttons
  4. Then registers with the NSNotificationCenter that it wants to hear the 4 possible messages that the model can send
    1. Connect: enable the buttons
    2. Disconnect: disable the buttons
    3. UpdateLED: reflect the current state of the LED on the screen
    4. UpdateButton: reflect the current state of the button on the screen


The GUI part of the code just acts when the button/switch is pressed to send messages to the model.  These methods are linked to the GUI elements on the main.storyboard


This file contains all of the code that interacts with the CY8CKIT021 board.  The first block of code defines a structure with a list of the UUIDs that we need to search for.  These are defined in the Bluetooth Component Customizer from the PRoC firmware.

The next block of code

The last block of code is responsible for interacting with the board

In the next post Ill show you how to build the Android App.

index description
CY8CKIT-021: A Simple FM/PSoC + BLE Demonstration Board Introduction to CY8CKIT021
CY8CKIT-021: The first four example projects Use the LEDs Buzzer 7-Segment display and the Potentiometer
CY8CKIT-021: The next three example projects Use theThermistor and two Capsense Examples
CY8CKIT-021: Bootloading the PRoC How to put firmware into the PRoC
CY8CKIT-021: The BLEIOT Component A custom component to communicate with the PRoC/PSoC
CY8CKIT-021: Using the BLEIOT Component A full example of the tho MCUs talking
CY8CKIT-021: The PRoC BLE Firmware How to make PRoC Firmware and use it with the BLEIOT Component
CY8CKIT-021: Example 10 - the new IOS App How to build and IOS App to talk to the development kit