Allow BluetoothSerial::connect() with specified channel and more options (espressif#6380)

* BTAddress const, add bool()

* BTAdvertisedDevice: const functions

* BluetoothSerial: add: getChannels, add isClosed, add read/peek timeout, add connect with channel#

* BluetoothSerial: add sec_mask, role in ::connect

* BluetoothSerial add discover and connect with channel number example

* DiscoverConnect: add SPP_ENABLED check

* DiscoverConnect: disable on esp32s3

Author: ferbar

Diff for: libraries/BluetoothSerial/examples/DiscoverConnect/.skip.esp32c3

@@ -0,0 +1,114 @@
+/**
+ * Bluetooth Classic Example
+ * Scan for devices - asyncronously, print device as soon as found
+ * query devices for SPP - SDP profile
+ * connect to first device offering a SPP connection
+ * 
+ * Example python server:
+ * source: https://gist.github.com/ukBaz/217875c83c2535d22a16ba38fc8f2a91
+ *
+ * Tested with Raspberry Pi onboard Wifi/BT, USB BT 4.0 dongles, USB BT 1.1 dongles, 
+ * 202202: does NOT work with USB BT 2.0 dongles when esp32 aduino lib is compiled with SSP support!
+ *         see https://github.com/espressif/esp-idf/issues/8394
+ *         
+ * use ESP_SPP_SEC_ENCRYPT|ESP_SPP_SEC_AUTHENTICATE in connect() if remote side requests 'RequireAuthentication': dbus.Boolean(True),
+ * use ESP_SPP_SEC_NONE or ESP_SPP_SEC_ENCRYPT|ESP_SPP_SEC_AUTHENTICATE in connect() if remote side has Authentication: False
+ */
+
+#include <map>
+#include <BluetoothSerial.h>
+
+#if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BLUEDROID_ENABLED)
+#error Bluetooth is not enabled! Please run `make menuconfig` to and enable it
+#endif
+
+#if !defined(CONFIG_BT_SPP_ENABLED)
+#error Serial Bluetooth not available or not enabled. It is only available for the ESP32 chip.
+#endif
+
+BluetoothSerial SerialBT;
+
+
+#define BT_DISCOVER_TIME  10000
+esp_spp_sec_t sec_mask=ESP_SPP_SEC_NONE; // or ESP_SPP_SEC_ENCRYPT|ESP_SPP_SEC_AUTHENTICATE to request pincode confirmation
+esp_spp_role_t role=ESP_SPP_ROLE_SLAVE; // or ESP_SPP_ROLE_MASTER
+
+// std::map<BTAddress, BTAdvertisedDeviceSet> btDeviceList;
+
+void setup() {
+  Serial.begin(115200);
+  if(! SerialBT.begin("ESP32test", true) ) {
+    Serial.println("========== serialBT failed!");
+    abort();
+  }
+  // SerialBT.setPin("1234"); // doesn't seem to change anything
+  // SerialBT.enableSSP(); // doesn't seem to change anything
+
+
+  Serial.println("Starting discoverAsync...");
+  BTScanResults* btDeviceList = SerialBT.getScanResults();  // maybe accessing from different threads!
+  if (SerialBT.discoverAsync([](BTAdvertisedDevice* pDevice) {
+      // BTAdvertisedDeviceSet*set = reinterpret_cast<BTAdvertisedDeviceSet*>(pDevice);
+      // btDeviceList[pDevice->getAddress()] = * set;
+      Serial.printf(">>>>>>>>>>>Found a new device asynchronously: %s\n", pDevice->toString().c_str());
+    } )
+    ) {
+    delay(BT_DISCOVER_TIME);
+    Serial.print("Stopping discoverAsync... ");
+    SerialBT.discoverAsyncStop();
+    Serial.println("discoverAsync stopped");
+    delay(5000);
+    if(btDeviceList->getCount() > 0) {
+      BTAddress addr;
+      int channel=0;
+      Serial.println("Found devices:");
+      for (int i=0; i < btDeviceList->getCount(); i++) {
+        BTAdvertisedDevice *device=btDeviceList->getDevice(i);
+        Serial.printf(" ----- %s  %s %d\n", device->getAddress().toString().c_str(), device->getName().c_str(), device->getRSSI());
+        std::map<int,std::string> channels=SerialBT.getChannels(device->getAddress());
+        Serial.printf("scanned for services, found %d\n", channels.size());
+        for(auto const &entry : channels) {
+          Serial.printf("     channel %d (%s)\n", entry.first, entry.second.c_str());
+        }
+        if(channels.size() > 0) {
+          addr = device->getAddress();
+          channel=channels.begin()->first;
+        }
+      }
+      if(addr) {
+        Serial.printf("connecting to %s - %d\n", addr.toString().c_str(), channel);
+        SerialBT.connect(addr, channel, sec_mask, role);
+      }
+    } else {
+      Serial.println("Didn't find any devices");
+    }
+  } else {
+    Serial.println("Error on discoverAsync f.e. not workin after a \"connect\"");
+  }
+}
+
+
+String sendData="Hi from esp32!\n";
+
+void loop() {
+  if(! SerialBT.isClosed() && SerialBT.connected()) {
+    if( SerialBT.write((const uint8_t*) sendData.c_str(),sendData.length()) != sendData.length()) {
+      Serial.println("tx: error");
+    } else {
+      Serial.printf("tx: %s",sendData.c_str());
+    }
+    if(SerialBT.available()) {
+      Serial.print("rx: ");
+      while(SerialBT.available()) {
+        int c=SerialBT.read();
+        if(c >= 0) {
+          Serial.print((char) c);
+        }
+      }
+      Serial.println();
+    }
+  } else {
+    Serial.println("not connected");
+  }
+  delay(1000);
+}

Diff for: libraries/BluetoothSerial/examples/DiscoverConnect/.skip.esp32s2

@@ -29,6 +29,9 @@ BTAddress::BTAddress(esp_bd_addr_t address) {
 	memcpy(m_address, address, ESP_BD_ADDR_LEN);
 } // BTAddress
 
+BTAddress::BTAddress() {
+	bzero(m_address, ESP_BD_ADDR_LEN);
+} // BTAddress
 
 /**
  * @brief Create an address from a hex string
@@ -64,13 +67,20 @@ bool BTAddress::equals(BTAddress otherAddress) {
 	return memcmp(otherAddress.getNative(), m_address, 6) == 0;
 } // equals
 
+BTAddress::operator bool () const {
+	for(int i = 0; i < ESP_BD_ADDR_LEN; i++){
+		if(this->m_address[i])
+			return true;
+	}
+	return false;
+} // operator ()
 
 /**
  * @brief Return the native representation of the address.
  * @return The native representation of the address.
  */
-esp_bd_addr_t *BTAddress::getNative() {
-	return &m_address;
+esp_bd_addr_t *BTAddress::getNative() const {
+	return const_cast<esp_bd_addr_t *>(&m_address);
 } // getNative
 
 
@@ -85,7 +95,7 @@ esp_bd_addr_t *BTAddress::getNative() {
  *
  * @return The string representation of the address.
  */
-std::string BTAddress::toString() {
+std::string BTAddress::toString() const {
 	auto size = 18;
 	char *res = (char*)malloc(size);
 	snprintf(res, size, "%02x:%02x:%02x:%02x:%02x:%02x", m_address[0], m_address[1], m_address[2], m_address[3], m_address[4], m_address[5]);

Diff for: libraries/BluetoothSerial/examples/DiscoverConnect/.skip.esp32s3

@@ -22,11 +22,14 @@
  */
 class BTAddress {
 public:
+	BTAddress();
 	BTAddress(esp_bd_addr_t address);
 	BTAddress(std::string stringAddress);
 	bool           equals(BTAddress otherAddress);
-	esp_bd_addr_t* getNative();
-	std::string    toString();
+	operator bool () const;
+
+	esp_bd_addr_t* getNative() const;
+	std::string    toString() const;
 
 private:
 	esp_bd_addr_t m_address;

Diff for: libraries/BluetoothSerial/examples/DiscoverConnect/DiscoverConnect.ino

@@ -16,14 +16,14 @@ class BTAdvertisedDevice {
     virtual ~BTAdvertisedDevice() = default;
 
     virtual BTAddress   getAddress();
-    virtual uint32_t    getCOD();
-    virtual std::string getName();
-    virtual int8_t      getRSSI();
+    virtual uint32_t    getCOD() const;
+    virtual std::string getName() const;
+    virtual int8_t      getRSSI() const;
 
 
-    virtual bool        haveCOD();
-    virtual bool        haveName();
-    virtual bool        haveRSSI();
+    virtual bool        haveCOD() const;
+    virtual bool        haveName() const;
+    virtual bool        haveRSSI() const;
 
     virtual std::string toString();
 };
@@ -35,14 +35,14 @@ class BTAdvertisedDeviceSet : public virtual BTAdvertisedDevice {
 
 
     BTAddress   getAddress();
-    uint32_t    getCOD();
-    std::string getName();
-    int8_t      getRSSI();
+    uint32_t    getCOD() const;
+    std::string getName() const;
+    int8_t      getRSSI() const;
 
 
-    bool        haveCOD();
-    bool        haveName();
-    bool        haveRSSI();
+    bool        haveCOD() const;
+    bool        haveName() const;
+    bool        haveRSSI() const;
 
     std::string toString();
 
@@ -62,4 +62,4 @@ class BTAdvertisedDeviceSet : public virtual BTAdvertisedDevice {
     int8_t      m_rssi;
 };
 
-#endif
+#endif

Diff for: libraries/BluetoothSerial/src/BTAddress.cpp

@@ -25,14 +25,14 @@ BTAdvertisedDeviceSet::BTAdvertisedDeviceSet() {
 } // BTAdvertisedDeviceSet
 
 BTAddress   BTAdvertisedDeviceSet::getAddress()    { return m_address; }
-uint32_t    BTAdvertisedDeviceSet::getCOD()        { return m_cod; }
-std::string BTAdvertisedDeviceSet::getName()       { return m_name; }
-int8_t      BTAdvertisedDeviceSet::getRSSI()	    { return m_rssi; }
+uint32_t    BTAdvertisedDeviceSet::getCOD() const       { return m_cod; }
+std::string BTAdvertisedDeviceSet::getName() const      { return m_name; }
+int8_t      BTAdvertisedDeviceSet::getRSSI() const	    { return m_rssi; }
 
 
-bool        BTAdvertisedDeviceSet::haveCOD()   { return m_haveCOD; }
-bool        BTAdvertisedDeviceSet::haveName()  { return m_haveName; }
-bool        BTAdvertisedDeviceSet::haveRSSI()  { return m_haveRSSI; }
+bool        BTAdvertisedDeviceSet::haveCOD() const  { return m_haveCOD; }
+bool        BTAdvertisedDeviceSet::haveName() const { return m_haveName; }
+bool        BTAdvertisedDeviceSet::haveRSSI() const { return m_haveRSSI; }
 
 /**
  * @brief Create a string representation of this device.