Sending multiple notify packets per connection interval

[Neil_CPD]

Hi,

Device: NRF53

I'm trying to send 3 notify packets in a 15ms connection internal but I can send 2.

I'm using Nrf connect and Zephyr.  is there a limit or a define to set this.

Thank you for any guidance and help

Regards

[Simon]

Sorry for the delay on this, I'm currently looking into it

Best regards,

Simon

[Neil_CPD]

Hi Simon,

Did you find anything after looking into this?

Thanks

[Simon]

I did some testing and was able to send 3 packets in a connection interval.

I modifed the peripheral_uart sample from NCS v1.6.0 such that a 15 ms connection interval would be used:

diff --git a/samples/bluetooth/peripheral_uart/prj.conf b/samples/bluetooth/peripheral_uart/prj.conf
index cd6df0664..2decfd725 100644
--- a/samples/bluetooth/peripheral_uart/prj.conf
+++ b/samples/bluetooth/peripheral_uart/prj.conf
@@ -48,3 +48,12 @@ CONFIG_LOG_BACKEND_RTT=y
 CONFIG_LOG_BACKEND_UART=n
 
 CONFIG_ASSERT=y
+
+CONFIG_DEBUG_OPTIMIZATIONS=y
+
+
+
+CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS=y
+CONFIG_BT_PERIPHERAL_PREF_MIN_INT=12
+CONFIG_BT_PERIPHERAL_PREF_MAX_INT=12
+CONFIG_BT_PERIPHERAL_PREF_SLAVE_LATENCY=0
diff --git a/samples/bluetooth/peripheral_uart/src/main.c b/samples/bluetooth/peripheral_uart/src/main.c
index cf51a899f..0e9bbc03d 100644
--- a/samples/bluetooth/peripheral_uart/src/main.c
+++ b/samples/bluetooth/peripheral_uart/src/main.c
@@ -288,9 +288,34 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 }
 #endif
 
+//struct bt_conn *conn, uint16_t interval, uint16_t latency, uint16_t timeout
+static void le_param_updated(struct bt_conn *conn, uint16_t interval, uint16_t latency, uint16_t timeout)
+{
+	struct bt_conn_info info; 
+	char addr[BT_ADDR_LE_STR_LEN];
+	
+	if(bt_conn_get_info(conn, &info))
+	{
+		printk("Could not parse connection info\n");
+	}
+	else
+	{
+		bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
+		
+		printk("Connection parameters updated!	\n\
+		Connected to: %s						\n\
+		New Connection Interval: %u				\n\
+		New Slave Latency: %u					\n\
+		New Connection Supervisory Timeout: %u	\n"
+		, addr, info.le.interval, info.le.latency, info.le.timeout);
+	}
+}
+
+
 static struct bt_conn_cb conn_callbacks = {
 	.connected    = connected,
 	.disconnected = disconnected,
+	.le_param_updated = le_param_updated,
 #ifdef CONFIG_BT_NUS_SECURITY_ENABLED
 	.security_changed = security_changed,
 #endif
@@ -479,6 +504,8 @@ static void configure_gpio(void)
 	}
 }
 
+
+
 void main(void)
 {
 	int blink_status = 0;

Then I programmed the peripheral_uart on an nRF52 DK and the central_uart on an nRF53 DK and sniffed the data using a third nordic device and the nRF Sniffer software.

I sent a long string from the peripheral_uart sample to the central_uart

Which resulted in the following output in the nRF Sniffer:

As you can see, three packets are sent within a single connection event

Best regards,

Simon

[Neil_CPD]

Thanks for doing this testing.  My peripheral is an nrf53,  would it be possible to swap the roles of your test and make the peripheral a nrf53 please?

I have two nrf53 so I'll try that this end.

Thanks

[Neil_CPD]

Hi Simon,

I've tested with the nrf53 uart peripheral example and a phone and I'm also able to send 3 packets.  I now need to see why my project can't.

Thanks for your help.

Neil