Merge pull request #66 from rigado/feat/readRssi

Read RSSI

client.go

@@ -53,7 +53,7 @@ type Client interface {
 	WriteDescriptor(d *Descriptor, v []byte) error
 
 	// ReadRSSI retrieves the current RSSI value of remote peripheral. [Vol 2, Part E, 7.5.4]
-	ReadRSSI() int
+	ReadRSSI() (int8, error)
 
 	// ExchangeMTU set the ATT_MTU to the maximum possible value that can be supported by both devices [Vol 3, Part G, 4.3.1]
 	ExchangeMTU(rxMTU int) (txMTU int, err error)

conn.go

@@ -28,6 +28,9 @@ type Conn interface {
 	// RemoteAddr returns remote device's address.
 	RemoteAddr() Addr
 
+	// ReadRSSI returns the remote device's RSSI.
+	ReadRSSI() (int8, error)
+
 	// RxMTU returns the ATT_MTU which the local device is capable of accepting.
 	RxMTU() int
 

linux/att/client.go

@@ -115,6 +115,10 @@ func (c *Client) ExchangeMTU(clientRxMTU int) (serverRxMTU int, err error) {
 	return txMTU, nil
 }
 
+func (c *Client) ReadRSSI() (int8, error) {
+	return c.l2c.ReadRSSI()
+}
+
 // FindInformation obtains the mapping of attribute handles with their associated types.
 // This allows a Client to discover the list of attributes and their types on a server.
 // [Vol 3, Part F, 3.4.3.1 & 3.4.3.2]

linux/gatt/client.go

@@ -325,11 +325,11 @@ func (p *Client) WriteDescriptor(d *ble.Descriptor, v []byte) error {
 }
 
 // ReadRSSI retrieves the current RSSI value of remote peripheral. [Vol 2, Part E, 7.5.4]
-func (p *Client) ReadRSSI() int {
+func (p *Client) ReadRSSI() (int8, error) {
 	p.Lock()
 	defer p.Unlock()
-	// TODO:
-	return 0
+
+	return p.ac.ReadRSSI()
 }
 
 // ExchangeMTU informs the server of the client’s maximum receive MTU size and

linux/hci/conn.go

@@ -505,6 +505,22 @@ func (c *Conn) RemoteAddr() ble.Addr {
 	return ble.NewAddr(net.HardwareAddr([]byte{a[5], a[4], a[3], a[2], a[1], a[0]}).String())
 }
 
+func (c *Conn) ReadRSSI() (int8, error) {
+	read := &cmd.ReadRSSI{Handle: c.param.ConnectionHandle()}
+	readRsp := cmd.ReadRSSIRP{}
+
+	err := c.hci.Send(read, &readRsp)
+	if err != nil {
+		return 127, fmt.Errorf("failed to read rssi: %v", err)
+	}
+
+	if readRsp.Status != 0 {
+		return 127, fmt.Errorf("read rssi failed with status %x", readRsp.Status)
+	}
+
+	return readRsp.RSSI, nil
+}
+
 // RxMTU returns the MTU which the upper layer is capable of accepting.
 func (c *Conn) RxMTU() int { return c.rxMTU }