add consolenotifier for peripheral system alerts

docs/rover-peripherals.md

@@ -879,6 +879,18 @@ If an ESP32 is unplugged or its serial connection fails while `roverd` is runnin
 3. The failed command is logged by the existing rover WebSocket command path.
 4. The advertised inventory does not change during that process lifetime.
 
+The first terminal read or write error also produces one concise `tty1`
+broadcast through the existing `ConsoleNotifier`:
+
+```text
+Rover peripheral "Rover GPIO" (firmata-0) disconnected: <error>. Reconnect it and restart roverd.
+```
+
+Normal startup uses the same local-console mechanism to announce every fixed
+peripheral, the selected native or ESP32 backend for camera servo, headlight,
+and laser, any ignored ESP32 roles, or that no ESP32 was found. Detailed Linux
+paths and Firmata handshake diagnostics remain in the systemd journal.
+
 The disconnected device is never replaced automatically by another serial device. This ensures that a command cannot be redirected merely because Linux reused a `/dev/ttyACM*` path.
 
 ### Server WebSocket reconnect

pi/roverd/camera_servo.go

@@ -134,6 +134,10 @@ func (s *CameraServo) Configuration() CameraServoConfig {
 	return s.cfg
 }
 
+func (s *CameraServo) BackendDescription() string {
+	return "native GPIO"
+}
+
 func (s *CameraServo) applyPulseLocked(micros int) {
 	micros = clampInt(micros, s.cfg.MinPulseUs, s.cfg.MaxPulseUs)
 	s.pin.DutyCycle(uint32(micros), uint32(s.cfg.CycleLen))

pi/roverd/camera_servo_debian_laptop.go

@@ -39,3 +39,7 @@ func (c *CameraServo) CurrentAngle() float64 {
 func (c *CameraServo) Configuration() CameraServoConfig {
 	return CameraServoConfig{}
 }
+
+func (c *CameraServo) BackendDescription() string {
+	return "native GPIO"
+}

pi/roverd/camera_servo_dummy.go

@@ -34,3 +34,7 @@ func (c *CameraServo) CurrentAngle() float64 {
 func (c *CameraServo) Configuration() CameraServoConfig {
 	return CameraServoConfig{}
 }
+
+func (c *CameraServo) BackendDescription() string {
+	return "native GPIO"
+}

pi/roverd/cmd/roverd/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"flag"
+	"fmt"
 	"log"
 	"os"
 	"os/signal"
@@ -42,9 +43,13 @@ func main() {
 	// rebuilt only when the roverd process itself restarts.
 	peripherals, err := roverd.DiscoverPeripheralManager(ctx, cfg.Serial.Device, logger)
 	if err != nil {
+		console.Notify(fmt.Sprintf("Rover peripheral startup failed: %v", err))
 		logger.Fatalf("discover rover peripherals: %v", err)
 	}
 	defer peripherals.Close()
+	for _, message := range peripherals.StartupBroadcasts() {
+		console.Notify(message)
+	}
 
 	var pulser *roverd.BRCPulser
 	if cfg.BRC.Enabled() {
@@ -74,9 +79,32 @@ func main() {
 	// GPIO wins, otherwise a discovered ESP32 may provide the built-in role.
 	hardwareControllers, err := roverd.ResolveRoverHardwareControllers(cfg, peripherals, logger)
 	if err != nil {
+		console.Notify(fmt.Sprintf("Rover peripheral startup failed while selecting hardware: %v", err))
 		logger.Fatalf("resolve rover hardware controllers: %v", err)
 	}
 	defer hardwareControllers.Close()
+	for _, message := range hardwareControllers.StartupBroadcasts() {
+		console.Notify(message)
+	}
+
+	// A peripheral is never hot-reconnected. Report the first terminal serial
+	// failure for each discovered board and tell the local operator exactly what
+	// recovery action the fixed boot-time lifecycle requires.
+	go func() {
+		for {
+			select {
+			case failure := <-peripherals.Failures():
+				console.Notify(fmt.Sprintf(
+					"Rover peripheral %q (%s) disconnected: %v. Reconnect it and restart roverd.",
+					failure.Name,
+					failure.ID,
+					failure.Err,
+				))
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
 
 	autoCharge := roverd.NewAutoChargeController(adapter, eventStream, logger)
 	go autoCharge.Run(ctx, sensorSamples)

pi/roverd/firmata.go

@@ -358,6 +358,10 @@ type FirmataClient struct {
 	requestMu   sync.Mutex
 	stateMu     sync.RWMutex
 	terminalErr error
+	// terminalErrorHandler is invoked only for the first non-timeout read
+	// failure while the client context remains active. PeripheralManager uses it
+	// to turn an unexpected USB loss into one operator-facing broadcast.
+	terminalErrorHandler func(error)
 }
 
 func NewFirmataClient(connection io.ReadWriteCloser) *FirmataClient {
@@ -420,11 +424,10 @@ func (client *FirmataClient) readLoop(ctx context.Context) {
 }
 
 func (client *FirmataClient) publishError(ctx context.Context, err error) {
-	client.stateMu.Lock()
-	if client.terminalErr == nil {
-		client.terminalErr = err
+	firstTerminalError, handler := client.recordTerminalError(err)
+	if firstTerminalError && handler != nil && ctx.Err() == nil {
+		handler(err)
 	}
-	client.stateMu.Unlock()
 
 	select {
 	case client.errors <- err:
@@ -433,6 +436,30 @@ func (client *FirmataClient) publishError(ctx context.Context, err error) {
 	}
 }
 
+func (client *FirmataClient) recordTerminalError(err error) (bool, func(error)) {
+	client.stateMu.Lock()
+	defer client.stateMu.Unlock()
+	firstTerminalError := client.terminalErr == nil
+	if client.terminalErr == nil {
+		client.terminalErr = err
+	}
+	handler := client.terminalErrorHandler
+	return firstTerminalError, handler
+}
+
+// SetTerminalErrorHandler registers the one-shot observer used after a device
+// has completed discovery. If the connection already failed, the observer is
+// called immediately so a narrow handshake-to-registration race is not lost.
+func (client *FirmataClient) SetTerminalErrorHandler(handler func(error)) {
+	client.stateMu.Lock()
+	client.terminalErrorHandler = handler
+	terminalErr := client.terminalErr
+	client.stateMu.Unlock()
+	if terminalErr != nil && handler != nil {
+		handler(terminalErr)
+	}
+}
+
 func (client *FirmataClient) write(message []byte) error {
 	client.writeMu.Lock()
 	defer client.writeMu.Unlock()
@@ -445,10 +472,19 @@ func (client *FirmataClient) write(message []byte) error {
 
 	written, err := client.connection.Write(message)
 	if err != nil {
+		firstTerminalError, handler := client.recordTerminalError(err)
+		if firstTerminalError && handler != nil {
+			handler(err)
+		}
 		return err
 	}
 	if written != len(message) {
-		return fmt.Errorf("short Firmata write %d/%d", written, len(message))
+		err := fmt.Errorf("short Firmata write %d/%d", written, len(message))
+		firstTerminalError, handler := client.recordTerminalError(err)
+		if firstTerminalError && handler != nil {
+			handler(err)
+		}
+		return err
 	}
 	return nil
 }

pi/roverd/firmata_hardware_controllers.go

@@ -16,6 +16,7 @@ type FirmataCameraServo struct {
 	cfg          CameraServoConfig
 	client       *FirmataClient
 	pin          byte
+	peripheralID string
 	mu           sync.Mutex
 	currentAngle float64
 	desiredAngle float64
@@ -41,10 +42,11 @@ func newFirmataCameraServo(peripheral *managedPeripheral, declaration Peripheral
 		Invert:        declaration.Inverted,
 	}
 	servo := &FirmataCameraServo{
-		cfg:    cfg,
-		client: peripheral.client,
-		pin:    byte(declaration.Pin),
-		stopCh: make(chan struct{}),
+		cfg:          cfg,
+		client:       peripheral.client,
+		pin:          byte(declaration.Pin),
+		peripheralID: peripheral.metadata.ID,
+		stopCh:       make(chan struct{}),
 	}
 
 	// SERVO_CONFIG establishes the peripheral-owned pulse calibration before
@@ -116,6 +118,10 @@ func (servo *FirmataCameraServo) Configuration() CameraServoConfig {
 	return servo.cfg
 }
 
+func (servo *FirmataCameraServo) BackendDescription() string {
+	return "ESP32 " + servo.peripheralID
+}
+
 func (servo *FirmataCameraServo) Close() {
 	servo.mu.Lock()
 	defer servo.mu.Unlock()
@@ -209,18 +215,26 @@ func (servo *FirmataCameraServo) startMoveLoopLocked() {
 // FirmataToggle owns logical state exactly like GPIOToggle but sends the final
 // electrical level through Firmata's standard digital-pin command.
 type FirmataToggle struct {
-	cfg    GPIOToggleConfig
-	name   string
-	client *FirmataClient
-	pin    byte
-	mu     sync.Mutex
-	on     bool
-	closed bool
+	cfg          GPIOToggleConfig
+	name         string
+	client       *FirmataClient
+	pin          byte
+	peripheralID string
+	mu           sync.Mutex
+	on           bool
+	closed       bool
 }
 
 func newFirmataToggle(name string, peripheral *managedPeripheral, declaration PeripheralDigitalRole, logger *log.Logger) (*FirmataToggle, error) {
 	cfg := GPIOToggleConfig{Enabled: true, GPIOPin: declaration.Pin, InitialOn: declaration.InitiallyOn, ActiveLow: declaration.ActiveLow}
-	toggle := &FirmataToggle{cfg: cfg, name: name, client: peripheral.client, pin: byte(declaration.Pin), on: cfg.InitialOn}
+	toggle := &FirmataToggle{
+		cfg:          cfg,
+		name:         name,
+		client:       peripheral.client,
+		pin:          byte(declaration.Pin),
+		peripheralID: peripheral.metadata.ID,
+		on:           cfg.InitialOn,
+	}
 	if err := toggle.client.SetPinMode(toggle.pin, FirmataPinModeOutput); err != nil {
 		return nil, fmt.Errorf("select Firmata output mode: %w", err)
 	}
@@ -275,6 +289,10 @@ func (toggle *FirmataToggle) Configuration() GPIOToggleConfig {
 	return toggle.cfg
 }
 
+func (toggle *FirmataToggle) BackendDescription() string {
+	return "ESP32 " + toggle.peripheralID
+}
+
 func (toggle *FirmataToggle) Close() {
 	toggle.mu.Lock()
 	defer toggle.mu.Unlock()

pi/roverd/firmata_hardware_controllers_test.go

@@ -47,6 +47,10 @@ func TestDisabledNativeRolesResolveToFirmataOnEveryHostBuild(t *testing.T) {
 	if !controllers.CameraServo.Configuration().Enabled || !controllers.Headlight.Configuration().Enabled || !controllers.Laser.Configuration().Enabled {
 		t.Fatal("ESP32-backed roles were not advertised as enabled")
 	}
+	wantHardwareBroadcast := "Rover hardware ready: camera servo via ESP32 firmata-0, headlight via ESP32 firmata-0, laser via ESP32 firmata-0."
+	if messages := controllers.StartupBroadcasts(); len(messages) != 1 || messages[0] != wantHardwareBroadcast {
+		t.Fatalf("hardware broadcasts = %#v, want %q", messages, wantHardwareBroadcast)
+	}
 
 	// Initialization uses only standard Firmata: servo calibration and mode,
 	// followed by the home position and digital initial states. The active-low
@@ -129,6 +133,10 @@ func TestEnabledNativeRolesWinEvenWithSeveralFirmataProviders(t *testing.T) {
 	if controllers.CameraServo != nativeCamera || controllers.Headlight != nativeToggles["headlight"] || controllers.Laser != nativeToggles["laser"] {
 		t.Fatal("resolver did not retain native controllers")
 	}
+	messages := controllers.StartupBroadcasts()
+	if len(messages) != 2 || messages[0] != "Ignored ESP32 camera servo, headlight, laser because native GPIO is enabled." || messages[1] != "Rover hardware ready: camera servo via native GPIO, headlight via native GPIO, laser via native GPIO." {
+		t.Fatalf("native precedence broadcasts = %#v", messages)
+	}
 }
 
 type testCameraServoController struct {
@@ -140,6 +148,7 @@ func (controller *testCameraServoController) Nudge(float64) error              {
 func (controller *testCameraServoController) SetPulseWidth(int) error          { return nil }
 func (controller *testCameraServoController) CurrentAngle() float64            { return 0 }
 func (controller *testCameraServoController) Configuration() CameraServoConfig { return controller.cfg }
+func (controller *testCameraServoController) BackendDescription() string       { return "native GPIO" }
 func (controller *testCameraServoController) Close()                           {}
 
 type testToggleController struct {
@@ -150,4 +159,5 @@ type testToggleController struct {
 func (controller *testToggleController) HandleAction(string) error       { return nil }
 func (controller *testToggleController) On() bool                        { return controller.on }
 func (controller *testToggleController) Configuration() GPIOToggleConfig { return controller.cfg }
+func (controller *testToggleController) BackendDescription() string      { return "native GPIO" }
 func (controller *testToggleController) Close()                          {}

pi/roverd/firmata_test.go

@@ -389,6 +389,7 @@ type scriptedConnection struct {
 	reads              chan []byte
 	timeoutsBeforeRead int
 	pendingRead        []byte
+	closeOnce          sync.Once
 }
 
 func newScriptedConnection(responses ...[]byte) *scriptedConnection {
@@ -432,7 +433,9 @@ func (connection *scriptedConnection) Write(data []byte) (int, error) {
 }
 
 func (connection *scriptedConnection) Close() error {
-	_ = connection.recordingConnection.Close()
-	close(connection.reads)
+	connection.closeOnce.Do(func() {
+		_ = connection.recordingConnection.Close()
+		close(connection.reads)
+	})
 	return nil
 }

pi/roverd/gpio_toggle.go

@@ -92,6 +92,10 @@ func (g *GPIOToggle) Configuration() GPIOToggleConfig {
 	return g.cfg
 }
 
+func (g *GPIOToggle) BackendDescription() string {
+	return "native GPIO"
+}
+
 func (g *GPIOToggle) setLocked(on bool) error {
 	// This is the only place a logical device state becomes an electrical GPIO
 	// value. Hardware that turns on when pulled low sets activeLow in roverd

pi/roverd/gpio_toggle_debian_laptop.go

@@ -34,3 +34,7 @@ func (g *GPIOToggle) On() bool {
 func (g *GPIOToggle) Configuration() GPIOToggleConfig {
 	return GPIOToggleConfig{}
 }
+
+func (g *GPIOToggle) BackendDescription() string {
+	return "native GPIO"
+}

pi/roverd/gpio_toggle_dummy.go

@@ -28,3 +28,7 @@ func (g *GPIOToggle) On() bool {
 func (g *GPIOToggle) Configuration() GPIOToggleConfig {
 	return GPIOToggleConfig{}
 }
+
+func (g *GPIOToggle) BackendDescription() string {
+	return "native GPIO"
+}

pi/roverd/hardware_controllers.go

@@ -3,6 +3,7 @@ package roverd
 import (
 	"fmt"
 	"log"
+	"strings"
 	"time"
 )
 
@@ -24,6 +25,7 @@ type CameraServoController interface {
 	SetPulseWidth(micros int) error
 	CurrentAngle() float64
 	Configuration() CameraServoConfig
+	BackendDescription() string
 	Close()
 }
 
@@ -33,6 +35,7 @@ type ToggleController interface {
 	HandleAction(action string) error
 	On() bool
 	Configuration() GPIOToggleConfig
+	BackendDescription() string
 	Close()
 }
 
@@ -40,9 +43,37 @@ type ToggleController interface {
 // decision. Its effective configurations are derived from whichever backend
 // won, making the normal rover hello accurate on both Pi and laptop hosts.
 type RoverHardwareControllers struct {
-	CameraServo CameraServoController
-	Headlight   ToggleController
-	Laser       ToggleController
+	CameraServo       CameraServoController
+	Headlight         ToggleController
+	Laser             ToggleController
+	ignoredESP32Roles []string
+}
+
+// StartupBroadcasts returns short operator-facing messages. Detailed pin and
+// protocol information remains in the journal; tty1 only explains which
+// physical backend won and whether an advertised ESP32 role was ignored.
+func (controllers RoverHardwareControllers) StartupBroadcasts() []string {
+	var messages []string
+	if len(controllers.ignoredESP32Roles) > 0 {
+		messages = append(messages, fmt.Sprintf(
+			"Ignored ESP32 %s because native GPIO is enabled.",
+			strings.Join(controllers.ignoredESP32Roles, ", "),
+		))
+	}
+	messages = append(messages, fmt.Sprintf(
+		"Rover hardware ready: camera servo via %s, headlight via %s, laser via %s.",
+		controllerBackend(controllers.CameraServo),
+		controllerBackend(controllers.Headlight),
+		controllerBackend(controllers.Laser),
+	))
+	return messages
+}
+
+func controllerBackend(controller interface{ BackendDescription() string }) string {
+	if controller == nil {
+		return "disabled"
+	}
+	return controller.BackendDescription()
 }
 
 type nativeHardwareControllerFactories struct {
@@ -68,6 +99,17 @@ func ResolveRoverHardwareControllers(cfg *Config, peripherals *PeripheralManager
 func resolveRoverHardwareControllers(cfg *Config, peripherals *PeripheralManager, logger *log.Logger, factories nativeHardwareControllerFactories) (RoverHardwareControllers, error) {
 	var controllers RoverHardwareControllers
 	var err error
+	// Record ignored declarations separately from selecting controllers so the
+	// same native-first decision can be explained on the local rover console.
+	if cfg.CameraServo.Enabled && peripherals.HasRoverRole("cameraServo") {
+		controllers.ignoredESP32Roles = append(controllers.ignoredESP32Roles, "camera servo")
+	}
+	if cfg.Headlight.Enabled && peripherals.HasRoverRole("headlight") {
+		controllers.ignoredESP32Roles = append(controllers.ignoredESP32Roles, "headlight")
+	}
+	if cfg.Laser.Enabled && peripherals.HasRoverRole("laser") {
+		controllers.ignoredESP32Roles = append(controllers.ignoredESP32Roles, "laser")
+	}
 
 	controllers.CameraServo, err = resolveCameraServoController(cfg.CameraServo, peripherals, logger, factories.newCameraServo)
 	if err != nil {

pi/roverd/peripheral_manager.go

@@ -63,6 +63,16 @@ type PeripheralManager struct {
 	cancel      context.CancelFunc
 	closeOnce   sync.Once
 	logger      *log.Logger
+	failures    chan PeripheralFailure
+}
+
+// PeripheralFailure is emitted once when a successfully discovered device's
+// serial reader terminates unexpectedly. Device identity is retained even
+// though reconnection still requires restarting roverd.
+type PeripheralFailure struct {
+	ID   string
+	Name string
+	Err  error
 }
 
 type peripheralDiscoveryDependencies struct {
@@ -76,9 +86,10 @@ type peripheralDiscoveryDependencies struct {
 func discoverPeripheralManager(ctx context.Context, excludedDevice string, logger *log.Logger, dependencies peripheralDiscoveryDependencies) (*PeripheralManager, error) {
 	managerContext, cancel := context.WithCancel(ctx)
 	manager := &PeripheralManager{
-		byID:   make(map[string]*managedPeripheral),
-		cancel: cancel,
-		logger: logger,
+		byID:     make(map[string]*managedPeripheral),
+		cancel:   cancel,
+		logger:   logger,
+		failures: make(chan PeripheralFailure, 16),
 	}
 
 	candidates, err := dependencies.listCandidates(excludedDevice)
@@ -139,12 +150,51 @@ func discoverPeripheralManager(ctx context.Context, excludedDevice string, logge
 		}
 		manager.peripherals = append(manager.peripherals, peripheral)
 		manager.byID[peripheral.metadata.ID] = peripheral
+		client.SetTerminalErrorHandler(func(terminalErr error) {
+			failure := PeripheralFailure{ID: peripheral.metadata.ID, Name: peripheral.metadata.Name, Err: terminalErr}
+			select {
+			case manager.failures <- failure:
+			default:
+				// The channel is intentionally bounded because broadcasts are
+				// diagnostic. Never block a Firmata reader during a fleet-wide
+				// shutdown or an unlikely burst of simultaneous USB failures.
+				logger.Printf("peripheral failure notification queue full for %s: %v", peripheral.metadata.ID, terminalErr)
+			}
+		})
 		logger.Printf("discovered rover peripheral %s on %s with %d generic controls", description.Name, devicePath, len(description.Controls))
 	}
 
 	return manager, nil
 }
 
+// StartupBroadcasts describes the fixed inventory without exposing device
+// paths or wiring details on the rover's local console.
+func (manager *PeripheralManager) StartupBroadcasts() []string {
+	inventory := manager.Inventory()
+	if len(inventory) == 0 {
+		return []string{"No ESP32 rover peripherals detected during startup."}
+	}
+	messages := make([]string, 0, len(inventory))
+	for _, peripheral := range inventory {
+		messages = append(messages, fmt.Sprintf(
+			"Rover peripheral %q connected as %s with %d additional controls.",
+			peripheral.Name,
+			peripheral.ID,
+			len(peripheral.Controls),
+		))
+	}
+	return messages
+}
+
+// Failures exposes unexpected runtime disconnects to the daemon entry point,
+// which owns the ConsoleNotifier and therefore owns user-facing wording.
+func (manager *PeripheralManager) Failures() <-chan PeripheralFailure {
+	if manager == nil {
+		return nil
+	}
+	return manager.failures
+}
+
 func listPeripheralCandidates(excludedDevice string) ([]string, error) {
 	patterns := []string{
 		"/dev/serial/by-id/*",

pi/roverd/peripheral_manager_test.go

@@ -35,6 +35,10 @@ func TestPeripheralManagerDiscoversInventoryAndDispatchesControls(t *testing.T)
 	if inventory[0].ID != "firmata-0" || inventory[0].Name != "Bench accessory" {
 		t.Fatalf("unexpected peripheral metadata: %#v", inventory[0])
 	}
+	wantBroadcast := `Rover peripheral "Bench accessory" connected as firmata-0 with 3 additional controls.`
+	if broadcasts := manager.StartupBroadcasts(); len(broadcasts) != 1 || broadcasts[0] != wantBroadcast {
+		t.Fatalf("startup broadcasts = %#v, want %q", broadcasts, wantBroadcast)
+	}
 	wantOrder := []string{"servoPosition", "lightBrightness", "specialAction"}
 	for index, controlID := range wantOrder {
 		if inventory[0].Controls[index].ID != controlID {
@@ -79,6 +83,45 @@ func TestPeripheralManagerDiscoversInventoryAndDispatchesControls(t *testing.T)
 	}
 }
 
+func TestPeripheralManagerBroadcastsNoDevices(t *testing.T) {
+	manager := &PeripheralManager{byID: make(map[string]*managedPeripheral)}
+	want := "No ESP32 rover peripherals detected during startup."
+	if messages := manager.StartupBroadcasts(); len(messages) != 1 || messages[0] != want {
+		t.Fatalf("startup broadcasts = %#v, want %q", messages, want)
+	}
+}
+
+func TestPeripheralManagerReportsUnexpectedDisconnectOnce(t *testing.T) {
+	connection := scriptedPeripheralConnection(t, testPeripheralDescription("Bench accessory", false))
+	manager, err := discoverPeripheralManager(
+		context.Background(),
+		"/dev/roomba",
+		discardLogger(),
+		testPeripheralDiscoveryDependencies([]string{"/dev/accessory"}, map[string]*scriptedConnection{"/dev/accessory": connection}),
+	)
+	if err != nil {
+		t.Fatalf("discover: %v", err)
+	}
+	defer manager.Close()
+
+	// Closing the fake read stream models an unplugged USB serial adapter. The
+	// manager should publish one identified failure and never attempt reconnect.
+	_ = connection.Close()
+	select {
+	case failure := <-manager.Failures():
+		if failure.ID != "firmata-0" || failure.Name != "Bench accessory" || !errors.Is(failure.Err, io.ErrClosedPipe) {
+			t.Fatalf("unexpected failure: %#v", failure)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("timed out waiting for peripheral disconnect")
+	}
+	select {
+	case duplicate := <-manager.Failures():
+		t.Fatalf("unexpected duplicate disconnect: %#v", duplicate)
+	case <-time.After(20 * time.Millisecond):
+	}
+}
+
 func TestPeripheralManagerRejectsInvalidValuesBeforeWriting(t *testing.T) {
 	connection := scriptedPeripheralConnection(t, testPeripheralDescription("Bench accessory", false))
 	manager, err := discoverPeripheralManager(
@@ -229,6 +272,14 @@ func TestPeripheralManagerReturnsHardwareWriteFailure(t *testing.T) {
 	if err == nil || !strings.Contains(err.Error(), "USB device removed") {
 		t.Fatalf("expected hardware error, got %v", err)
 	}
+	select {
+	case failure := <-manager.Failures():
+		if failure.ID != "firmata-0" || !strings.Contains(failure.Err.Error(), "USB device removed") {
+			t.Fatalf("unexpected write failure notification: %#v", failure)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("timed out waiting for write failure notification")
+	}
 }
 
 func TestPeripheralManagerPassesRoombaDeviceToCandidateExclusion(t *testing.T) {