added set_data_length

src/utility/ATT.cpp

@@ -256,6 +256,8 @@ void ATTClass::addConnection(uint16_t handle, uint8_t role, uint8_t peerBdaddrTy
   if (_eventHandlers[BLEConnected]) {
     _eventHandlers[BLEConnected](BLEDevice(peerBdaddrType, peerBdaddr));
   }
+  // TODO (krm) increase speed!
+  HCI.hciSetDataLength(handle, 251, 2120);
 }
 
 void ATTClass::handleData(uint16_t connectionHandle, uint8_t dlen, uint8_t data[])

src/utility/HCI.cpp

@@ -672,6 +672,20 @@ void HCIClass::setTransport(HCITransportInterface *HCITransport)
   _HCITransport = HCITransport;
 }
 
+int HCIClass::hciSetDataLength(uint16_t connectionHandle, uint16_t txOctects, uint16_t txTime){
+    const uint8_t payload_len = 6;
+    const uint16_t opcode = 0x2022;
+    uint8_t cmd_buffer[BLE_CMD_MAX_PARAM_LEN];
+    hci_le_set_data_length_cp0 *cp0 = (hci_le_set_data_length_cp0*)(cmd_buffer);
+
+    // create payload
+    cp0->Connection_Handle = connectionHandle;
+    cp0->TxOctets = txOctects;
+    cp0->TxTime = txTime;
+
+    return sendCommand(opcode, payload_len, cmd_buffer);
+}
+
 #if !defined(FAKE_HCI)
 HCIClass HCIObj;
 HCIClass& HCI = HCIObj;

src/utility/HCI.h

@@ -23,6 +23,14 @@
 #include <Arduino.h>
 #include "HCITransport.h"
 
+#define BLE_CMD_MAX_PARAM_LEN 255
+
+struct hci_le_set_data_length_cp0{
+    uint16_t Connection_Handle;
+    uint16_t TxOctets;
+    uint16_t TxTime;
+};
+
 class HCIClass {
 public:
   HCIClass();
@@ -74,6 +82,21 @@ class HCIClass {
 
   void setTransport(HCITransportInterface *HCITransport);
 
+  //-----------------------------
+  // @brief 
+  // @param connectionHandle Connection_Handle Connection handle for which the command applies. 
+  //          Values: 0x0000 ... 0x0EFF
+  // @param txOctects TxOctets Preferred maximum number of payload octets that the local
+  //          Controller should include in a single Link Layer packet on this
+  //          connection.
+  //          Values: 0x001B ... 0x00FB
+  // @param txTime TxTime Preferred maximum number of microseconds that the local
+  //         Controller should use to transmit a single Link Layer packet on this
+  //         connection.
+  //         Values: 0x0148 ... 0x4290
+  // @return Value indicating success or error code.
+  int hciSetDataLength(uint16_t connectionHandle, uint16_t txOctects, uint16_t txTime);
+
 private:
   virtual int sendCommand(uint16_t opcode, uint8_t plen = 0, void* parameters = NULL);