diff --git a/include/libdivecomputer/Makefile.am b/include/libdivecomputer/Makefile.am
index 6ba4bd7..e666f61 100644
--- a/include/libdivecomputer/Makefile.am
+++ b/include/libdivecomputer/Makefile.am
@@ -3,7 +3,7 @@ libdivecomputer_HEADERS = 	\
 	version.h \
 	common.h \
 	context.h \
-	custom_serial.h \
+	custom_io.h \
 	buffer.h \
 	descriptor.h \
 	iterator.h \
diff --git a/include/libdivecomputer/context.h b/include/libdivecomputer/context.h
index e75a845..757245b 100644
--- a/include/libdivecomputer/context.h
+++ b/include/libdivecomputer/context.h
@@ -23,7 +23,7 @@
 #define DC_CONTEXT_H
 
 #include "common.h"
-#include "custom_serial.h"
+#include "custom_io.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -49,7 +49,7 @@ dc_status_t
 dc_context_free (dc_context_t *context);
 
 dc_status_t
-dc_context_set_custom_serial (dc_context_t *context, dc_custom_serial_t *custom_serial);
+dc_context_set_custom_io (dc_context_t *context, dc_custom_io_t *custom_io);
 
 dc_status_t
 dc_context_set_loglevel (dc_context_t *context, dc_loglevel_t loglevel);
diff --git a/include/libdivecomputer/custom_serial.h b/include/libdivecomputer/custom_io.h
similarity index 56%
rename from include/libdivecomputer/custom_serial.h
rename to include/libdivecomputer/custom_io.h
index 1a2b44e..6cbf766 100644
--- a/include/libdivecomputer/custom_serial.h
+++ b/include/libdivecomputer/custom_io.h
@@ -1,5 +1,5 @@
-#ifndef CUSTOM_SERIAL_H
-#define CUSTOM_SERIAL_H
+#ifndef CUSTOM_IO_H
+#define CUSTOM_IO_H
 
 #include "common.h"
 
@@ -62,29 +62,40 @@ typedef enum dc_line_t {
 
 #endif /* __SERIAL_TYPES__ */
 
-typedef struct dc_custom_serial_t
+struct dc_context_t;
+
+typedef struct dc_custom_io_t
 {
 	void *userdata;
-	dc_status_t (*open) (void **userdata, const char *name);
-	dc_status_t (*close) (void **userdata);
-	dc_status_t (*read) (void **userdata, void* data, size_t size, size_t *actual);
-	dc_status_t (*write) (void **userdata, const void* data, size_t size, size_t *actual);
-	dc_status_t (*purge) (void **userdata, dc_direction_t);
-	dc_status_t (*get_available) (void **userdata, size_t *value);
-	dc_status_t (*set_timeout) (void **userdata, long timeout);
-	dc_status_t (*configure) (void **userdata, unsigned int baudrate, unsigned int databits, dc_parity_t parity, dc_stopbits_t stopbits, dc_flowcontrol_t flowcontrol);
-	dc_status_t (*set_dtr) (void **userdata, int level);
-	dc_status_t (*set_rts) (void **userdata, int level);
-	dc_status_t (*set_halfduplex) (void **userdata, unsigned int value);
-	dc_status_t (*set_break) (void **userdata, unsigned int level);
+
+	// Custom serial (generally BT rfcomm)
+	dc_status_t (*serial_open) (void **userdata, const char *name);
+	dc_status_t (*serial_close) (void **userdata);
+	dc_status_t (*serial_read) (void **userdata, void* data, size_t size, size_t *actual);
+	dc_status_t (*serial_write) (void **userdata, const void* data, size_t size, size_t *actual);
+	dc_status_t (*serial_purge) (void **userdata, dc_direction_t);
+	dc_status_t (*serial_get_available) (void **userdata, size_t *value);
+	dc_status_t (*serial_set_timeout) (void **userdata, long timeout);
+	dc_status_t (*serial_configure) (void **userdata, unsigned int baudrate, unsigned int databits, dc_parity_t parity, dc_stopbits_t stopbits, dc_flowcontrol_t flowcontrol);
+	dc_status_t (*serial_set_dtr) (void **userdata, int level);
+	dc_status_t (*serial_set_rts) (void **userdata, int level);
+	dc_status_t (*serial_set_halfduplex) (void **userdata, unsigned int value);
+	dc_status_t (*serial_set_break) (void **userdata, unsigned int level);
 	//dc_serial_set_latency (dc_serial_t *device, unsigned int milliseconds) - Unused
 	//dc_serial_get_lines (dc_serial_t *device, unsigned int *value) - Unused
 	//dc_serial_flush (dc_serial_t *device) - No device interaction
 	//dc_serial_sleep (dc_serial_t *device, unsigned int timeout) - No device interaction
-} dc_custom_serial_t;
+
+	// Custom packet transfer (generally BLE GATT)
+	int packet_size;
+	dc_status_t (*packet_open) (struct dc_custom_io_t *, struct dc_context_t *, const char *);
+	dc_status_t (*packet_close) (struct dc_custom_io_t *);
+	dc_status_t (*packet_read) (struct dc_custom_io_t *, void* data, size_t size, size_t *actual);
+	dc_status_t (*packet_write) (struct dc_custom_io_t *, const void* data, size_t size, size_t *actual);
+} dc_custom_io_t;
 
 
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
-#endif /* CUSTOM_SERIAL_H */
+#endif /* CUSTOM_IO_H */
diff --git a/include/libdivecomputer/version.h.in b/include/libdivecomputer/version.h.in
index 4a29f26..2a35b30 100644
--- a/include/libdivecomputer/version.h.in
+++ b/include/libdivecomputer/version.h.in
@@ -28,7 +28,7 @@ extern "C" {
 
 /* use these defines to detect Subsurface specific features */
 #define SSRF_LIBDC_VERSION 1
-#define SSRF_CUSTOM_SERIAL 1
+#define SSRF_CUSTOM_IO 1
 
 #define DC_VERSION "@DC_VERSION@"
 #define DC_VERSION_MAJOR @DC_VERSION_MAJOR@
diff --git a/src/context-private.h b/src/context-private.h
index 0a0dcb8..96fc0af 100644
--- a/src/context-private.h
+++ b/src/context-private.h
@@ -27,7 +27,7 @@
 #endif
 
 #include <libdivecomputer/context.h>
-#include <libdivecomputer/custom_serial.h>
+#include <libdivecomputer/custom_io.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -72,16 +72,16 @@ dc_context_syserror (dc_context_t *context, dc_loglevel_t loglevel, const char *
 dc_status_t
 dc_context_hexdump (dc_context_t *context, dc_loglevel_t loglevel, const char *file, unsigned int line, const char *function, const char *prefix, const unsigned char data[], unsigned int size);
 
-dc_custom_serial_t*
-_dc_context_custom_serial (dc_context_t *context);
+dc_custom_io_t*
+_dc_context_custom_io (dc_context_t *context);
 
 #define RETURN_IF_CUSTOM_SERIAL(context, block, function, ...)	\
 	do { \
-		dc_custom_serial_t *c = _dc_context_custom_serial(context); \
+		dc_custom_io_t *c = _dc_context_custom_io(context); \
 		dc_status_t _rc; \
 		if (c) { \
-			if (c->function) \
-				_rc = c->function(&c->userdata, ##__VA_ARGS__); \
+			if (c->serial_##function) \
+				_rc = c->serial_##function(&c->userdata, ##__VA_ARGS__); \
 			else \
 				_rc = DC_STATUS_SUCCESS; \
 			block ;\
diff --git a/src/context.c b/src/context.c
index 6b300c2..b15a9fc 100644
--- a/src/context.c
+++ b/src/context.c
@@ -32,7 +32,7 @@
 #endif
 
 #include "context-private.h"
-#include <libdivecomputer/custom_serial.h>
+#include <libdivecomputer/custom_io.h>
 
 struct dc_context_t {
 	dc_loglevel_t loglevel;
@@ -46,7 +46,7 @@ struct dc_context_t {
 	struct timeval timestamp;
 #endif
 #endif
-	dc_custom_serial_t *custom_serial;
+	dc_custom_io_t *custom_io;
 };
 
 #ifdef ENABLE_LOGGING
@@ -197,7 +197,7 @@ dc_context_new (dc_context_t **out)
 #endif
 #endif
 
-	context->custom_serial = NULL;
+	context->custom_io = NULL;
 
 	*out = context;
 
@@ -213,20 +213,20 @@ dc_context_free (dc_context_t *context)
 }
 
 dc_status_t
-dc_context_set_custom_serial (dc_context_t *context, dc_custom_serial_t *custom_serial)
+dc_context_set_custom_io (dc_context_t *context, dc_custom_io_t *custom_io)
 {
 	if (context == NULL)
 		return DC_STATUS_INVALIDARGS;
 
-	context->custom_serial = custom_serial;
+	context->custom_io = custom_io;
 
 	return DC_STATUS_SUCCESS;
 }
 
-dc_custom_serial_t*
-_dc_context_custom_serial (dc_context_t *context)
+dc_custom_io_t*
+_dc_context_custom_io (dc_context_t *context)
 {
-	return context->custom_serial;
+	return context->custom_io;
 }
 
 dc_status_t
diff --git a/src/libdivecomputer.symbols b/src/libdivecomputer.symbols
index ef89623..ba12d56 100644
--- a/src/libdivecomputer.symbols
+++ b/src/libdivecomputer.symbols
@@ -21,7 +21,7 @@ dc_context_new
 dc_context_free
 dc_context_set_loglevel
 dc_context_set_logfunc
-dc_context_set_custom_serial
+dc_context_set_custom_io
 
 dc_iterator_next
 dc_iterator_free