ble: Add device information service

src/ble.rs

@@ -39,9 +39,73 @@ pub enum BleSendable {
     SpatemRaw(io::msg::RawMsgRx),
 }
 
+pub const DIS_SERIAL_MAX_LEN: usize = 17;
+pub const DIS_FW_REVISION_MAX_LEN: usize = 20; // git-describe
+pub const DIS_SW_REVISION_MAX_LEN: usize = 66; // max length of get_feature_list, joined with comma
+
+pub struct DeviceInfo {
+    /// WiFi MAC
+    pub serial_number: [u8; DIS_SERIAL_MAX_LEN],
+    /// git tag/ revision
+    pub fw_revision: [u8; DIS_FW_REVISION_MAX_LEN],
+    /// used for feature flags
+    pub sw_revision: [u8; DIS_SW_REVISION_MAX_LEN],
+}
+
+impl DeviceInfo {
+    pub fn new(serial_number: &str, fw_revision: &str, sw_revision: &str) -> Self {
+        Self {
+            serial_number: string_as_padded_buf(serial_number, DIS_SERIAL_MAX_LEN)
+                .try_into()
+                .unwrap(),
+            fw_revision: string_as_padded_buf(fw_revision, DIS_FW_REVISION_MAX_LEN)
+                .try_into()
+                .unwrap(),
+            sw_revision: string_as_padded_buf(sw_revision, DIS_SW_REVISION_MAX_LEN)
+                .try_into()
+                .unwrap(),
+        }
+    }
+}
+
+pub fn string_as_padded_buf(value: &str, length: usize) -> alloc::vec::Vec<u8> {
+    let buf = value.as_bytes();
+    let buf_len = buf.len();
+
+    // cut buffer at maximum length or pad with whitespace
+    if buf_len > length {
+        buf[..length].to_vec()
+    } else {
+        let padding_len = length - buf_len;
+        let padding = alloc::vec![b' '; padding_len];
+
+        [buf, &padding].concat()
+    }
+}
+
 #[gatt_server]
 struct Server {
     c_its_events: CITSEvents,
+    device_info_service: DeviceInfoService,
+}
+
+#[gatt_service(uuid = service::DEVICE_INFORMATION)]
+struct DeviceInfoService {
+    /// Manufacturer name
+    #[characteristic(uuid = characteristic::MANUFACTURER_NAME_STRING, read, value = "jtbx")]
+    mfg_name: &'static str,
+    /// Model number
+    #[characteristic(uuid = characteristic::MODEL_NUMBER_STRING, read, value = "ESP32-C5 C-ITS Companion")]
+    model_number: &'static str,
+    // Serial Number String
+    #[characteristic(uuid = characteristic::SERIAL_NUMBER_STRING, read, value = [0u8; DIS_SERIAL_MAX_LEN])]
+    serial_number: [u8; DIS_SERIAL_MAX_LEN],
+    // Firmware Revision String
+    #[characteristic(uuid = characteristic::FIRMWARE_REVISION_STRING, read, value = [0u8; DIS_FW_REVISION_MAX_LEN])]
+    fw_revision: [u8; DIS_FW_REVISION_MAX_LEN],
+    // Software Revision String
+    #[characteristic(uuid = characteristic::SOFTWARE_REVISION_STRING, read, value = [0u8; DIS_SW_REVISION_MAX_LEN])]
+    sw_revision: [u8; DIS_SW_REVISION_MAX_LEN],
 }
 
 #[gatt_service(uuid = "c0b70000-d4f4-4000-ada8-f99a02ee315c")]
@@ -111,6 +175,7 @@ pub async fn run(
     >,
     name: alloc::string::String,
     short_name: alloc::string::String,
+    device_info: DeviceInfo,
 ) {
     let mut resources: HostResources<DefaultPacketPool, CONNECTIONS_MAX, L2CAP_CHANNELS_MAX> =
         HostResources::new();
@@ -132,6 +197,21 @@ pub async fn run(
     }))
     .unwrap();
 
+    // set "dynamic" device info data
+    let _ = server
+        .device_info_service
+        .serial_number
+        .set(&server, &device_info.serial_number);
+    let _ = server
+        .device_info_service
+        .fw_revision
+        .set(&server, &device_info.fw_revision);
+    let _ = server
+        .device_info_service
+        .sw_revision
+        .set(&server, &device_info.sw_revision);
+
+    // advertise and run update logic
     let _ = embassy_futures::join::join(ble_task(runner), async {
         loop {
             match advertise(&mut peripheral, &server, &short_name).await {