change(ble): Increase MTU to 241 bytes

By default the MTU is set to 23 bytes, use 241 bytes instead to make the
UART and file transfer service more efficient. The MTU also contains
some BLE headers and is not only the usable data.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

epicardium/ble/ble_main.c

@@ -120,6 +120,15 @@ static const smpCfg_t bleSmpCfg =
   DM_AUTH_MITM_FLAG,                      /*! Device authentication requirements */
 };
 
+/* Configuration structure */
+static const attCfg_t bleAttCfg =
+{
+  15,                                  /* ATT server service discovery connection idle timeout in seconds */
+  241,                                 /* desired ATT MTU */
+  ATT_MAX_TRANS_TIMEOUT,               /* transaction timeout in seconds */
+  1                                    /* number of queued prepare writes supported by server */
+};
+
 /**************************************************************************************************
   Advertising Data
 **************************************************************************************************/
@@ -454,6 +463,7 @@ static void BleHandlerInit(void)
 
   /* Set stack configuration pointers */
   pSmpCfg = (smpCfg_t *) &bleSmpCfg;
+  pAttCfg = (attCfg_t *) &bleAttCfg;
 
   /* initialize battery service server */
   BasInit(bleHandlerId, (basCfg_t *) &bleBasCfg);