Hi,
1) I want to collect sensor data using BLE like the following topology, the sensor devices are battery-powered, which sample in the NCS is suitable to modify?
2) Does NUS central/peripheral can do many-to-one topology in this usage? or need to use BLE mesh?
Hi,
After some modifications based on multi-NUS sample, the two peripheral_uart can connect to central_uart now, but the central_uart is failed to send nus_index in
static void discovery_complete(struct bt_gatt_dm *dm,
void *context)
{
struct bt_nus_client *nus = context;
LOG_INF("Service discovery completed");
bt_gatt_dm_data_print(dm);
bt_nus_handles_assign(dm, nus);
bt_nus_subscribe_receive(nus);
bt_gatt_dm_data_release(dm);
int err = bt_scan_start(BT_SCAN_TYPE_SCAN_ACTIVE);
if (err) {
LOG_ERR("Scanning failed to start (err %d)", err);
} else {
LOG_INF("Scanning started");
}
/* Send a message to the new NUS server informing it of its ID in this
* mini-network
* The new NUS will have been added to the connection context library and so
* will be the highest index as they are added incrementally upwards.
* This is a bit of a workaround because in this function, I don't know
* the ID of this connection which is the piece of info I want to transmit.
*/
size_t num_nus_conns = bt_conn_ctx_count(&conns_ctx_lib);
size_t nus_index = 99;
/* This is a little inelegant but we must get the index of the device to
* convey it
*/
for (size_t i = 0; i < num_nus_conns; i++) {
const struct bt_conn_ctx *ctx =
bt_conn_ctx_get_by_id(&conns_ctx_lib, i);
if (ctx) {
if (ctx->data == nus) {
nus_index = i;
char message[3];
sprintf(message, "%d", nus_index);
message[2] = '\r';
int length = 3;
err = bt_nus_client_send(nus, message, length);
if (err) {
LOG_WRN("Failed to send data over BLE connection"
"(err %d)",
err);
} else {
LOG_INF("Sent to server %d: %s",
nus_index, message);
}
bt_conn_ctx_release(&conns_ctx_lib,
(void *)ctx->data);
break;
} else {
bt_conn_ctx_release(&conns_ctx_lib,
(void *)ctx->data);
}
}
}
}