Overview

To connect to a Clover Go reader, discover devices within Bluetooth (BLE) range, then request a connection. During the connection process, the Clover Go software development kit (SDK) checks for valid reader and merchant configuration settings, and updates firmware and encryption keys as needed.

Prerequisites

• Read Overview of the Clover Platform.
• Set up a developer account (including your test merchant settings).
• Order a Clover Developer Kit (Dev Kit) and set it up.
• Use required Android SDK versions.
• Have BLUETOOTH_CONNECT permission in your AndroidManifest to request the devices list. Android uses the permission to request BLE access your app's user.

Steps

1. Discover devices

Initiate device discovery with the Clover GoSDK.scanForReaders function. Receive results back with collectLatest on the flow function or using the GoSdkCallback implementation.

Methods

fun scanForReaders(): Flow<ReaderInfo>
 
fun scanForReaders(lifecycleOwner: LifecycleOwner, callback: GoSdkCallback<ReaderInfo>)
//lifecycleOwner: Class that contains Android Activity/Fragment Lifecycle information.
//callback: Callback interface to get ReaderInfo results or error
 
interface GoSdkCallback<ReaderInfo> {
    fun onNext(result: ReaderInfo) //Gets called when a card reader is discovered
    //result: Card reader object
 
    fun onError(e: Throwable) //Gets called when there is an error while scanning for readers
    //e: Throwable exception containing error information
}

Recommended implementation

Scanning for devices can take time. For example, the user might not have turned on their device when they first scan for devices, unless you remind them to first.

• Implement a backing data store for the ListView or RecyclerView in which you want to present the list of readers.
• Call GoSdk.scanForReaders() in a coroutine scope or suspend function, add the discovered reader to your backing data source, and handle any errors returned in onScanError.

lifecycleScope.launch {  
    goSdk.scanForReaders()  
    .collectLatest { reader->  
        println("Scanned Reader: $reader")  
        recyclerViewAdapter.addDevice(reader)  
    }  
    .catch { error->  
        println("Error scanning for readers: $error")  
    }  
}

2. Connect to a discovered device

• Call the Clover GoSDK.connectBluetoothReader method. Pass in the reader object you received from the discovery process. 
• To receive the device connection status callbacks, call Clover GoSDK.observeCardReaderStatus.
• To subscribe to device connection status callbacks, call collectLatest on the flow function or use the GoSdkCallback implementation.

Methods

fun connectBluetoothReader(readerInfo: ReaderInfo)
//readerInfo: The specific `CardReader` to connect to
 
fun observeCardReaderStatus(): SharedFlow<CardReaderStatus>
 
fun observeCardReaderStatus(lifecycleOwner: LifecycleOwner, callback: GoSdkCallback<CardReaderStatus>)
//lifecycleOwner: Class that contains Android Activity/Fragment Lifecycle information.
//callback: Callback interface to get CardReaderStatus results or error
 
interface GoSdkCallback<CardReaderStatus> {
    fun onNext(result: CardReaderStatus) //Gets called when the CardReaderStatus gets updated
    //result: Card reader object
 
    fun onError(e: Throwable) //Gets called when there is an error while scanning for readers
    //e: Throwable exception containing error information
}
 
sealed class CardReaderStatus {
    data class Disconnected(val readerInfo: ReaderInfo) : CardReaderStatus()
    //readerInfo: CardReader object containing all available information
 
    data class Deleted(val readerInfo: ReaderInfo) : CardReaderStatus()
    //readerInfo: CardReader object containing all available information
 
    data class Connected(val readerInfo: ReaderInfo) : CardReaderStatus()
    //readerInfo: CardReader object containing all available information
 
    object Connecting : CardReaderStatus()
 
    object CheckingForUpdate : CardReaderStatus()
 
    data class Ready(val readerInfo: ReaderInfo) : CardReaderStatus()
    //readerInfo: CardReader object containing all available information
 
    data class ResetInProgress(val readerType: ReaderInfo.ReaderType) : CardReaderStatus()
    //readerType: The type of reader we're connecting to. One of: RP350, RP450 or C600
 
    object UpdateComplete : CardReaderStatus()
 
    data class BleFirmwareUpdateInProgress(val progress: Int) : CardReaderStatus()
    //progress: Firmware Update percentage from 0-100
 
    data class SpFirmwareUpdateInProgress(val progress: Int) : CardReaderStatus()
    //progress: Firmware Update percentage from 0-100
 
    object RkiInProgress : CardReaderStatus()
 
    data class BatteryPercentChanged(val readerInfo: ReaderInfo) : CardReaderStatus()
    //readerInfo: CardReader object containing all available information
 
    fun isConnected(): Boolean = !(this is Disconnected || this is Deleted)
}

Connection flow

When you connect to a card reader for the first time, you may need to update firmware and encryption keys which can take a few minutes. Subsequent connections take a few seconds as the configuration is checked and verified as valid. It is important that you inform your users during this process that the device is connecting and undergoing needed updates. Use the status information to inform your users about the connection flow process. A typical connection flow status is shown below.

connectBluetoothReader > Connecting > Connected > CheckingForUpdate > ResetInProgress (optional) > BleFirmwareUpdateInProgress (optional) > SpFirmwareUpdateInProgress (optional) > UpdateComplete (optional) > RkiInProgress (optional) > Ready

connectBluetoothReader

Your code calls this method to initiate the connection, passing in a reader object received during the discovery process. Depending on the use cases of your app, you may automatically connect to the last connected reader, or you may present your users with a list of readers to choose from. When you call this method, the Clover Go SDK:

• Establishes a BLE connection to the reader.
• Requests the reader's configuration from the reader.
• Inspects the configuration.
• Begins the firmware and encryption key update process.

📘

NOTE

The update process involves network calls to Clover servers to look for software updates and is performed every time a reader connects, and so network conditions may delay the completion of this process.

👍

HINT

Since this call initiates a BLE connection with the Clover reader, you can expect to navigate the specific OS BLE pairing process during this time.  The OS asks if the user wants to connect to the specified device, but the SDK handles the pairing code part of the process without user input.

Status descriptions