src/hq.ts

@@ -0,0 +1,47 @@
+import { GPIO } from "./pins"
+
+console.log(`kill -9 ${process.pid}`)
+
+const gpio = new GPIO({ resetOnClose: true })
+
+// // Blink an LED
+using led = gpio.output(21)
+
+// Read a button
+using inputs = gpio.inputGroup({
+  button: { pin: 20, pull: "up", debounce: 10 },
+  switch: { pin: 16, pull: "up", debounce: 10 }
+})
+
+led.value = inputs.pins.button.value
+
+const iteratorEvents = new Promise(async (resolve) => {
+  for await (const event of inputs.events()) {
+    if (event.pin === "button") {
+      console.log(`🌭`, event.value)
+      led.value = event.value
+    }
+  }
+})
+
+const switchEvent = new Promise<void>(async (resolve) => {
+  await inputs.pins.switch.waitForValue(0)
+  console.log("Switch pressed!")
+  resolve()
+})
+
+process.on("SIGINT", () => {
+  inputs.close()
+  led.close()
+  process.exit(0)
+})
+
+process.on("SIGTERM", () => {
+  inputs.close()
+  
+  process.exit(0)
+})
+
+await Promise.race([iteratorEvents, switchEvent])
+
+console.log(`👋 Goodbye!`)

src/phone.ts

@@ -22,19 +22,25 @@ type PhoneContext = {
   cancelAgent?: CancelableTask
 }
 
-const gpio = new GPIO()
-using ringer = gpio.output(17, { resetOnClose: true })
-using hook = gpio.input(27, { pull: "up", debounce: 3 })
-using rotaryInUse = gpio.input(22, { pull: "up", debounce: 3 })
-using rotaryNumber = gpio.input(23, { pull: "up", debounce: 3 })
+const gpio = new GPIO({ resetOnClose: true })
+using ringer = gpio.output(17)
+using inputs = gpio.inputGroup({
+  hook: { pin: 27, debounce: 50 },
+  rotaryInUse: { pin: 22, debounce: 50 },
+  rotaryNumber: { pin: 23, debounce: 10 },
+})
 
 export const startPhone = async (agentId: string, apiKey: string) => {
   await Buzz.setVolume(0.4)
-  log.info(`📞 Hook ${hook.value}`)
+  log.info(`📞 Hook ${inputs.pins.hook.value}`)
+  await handleInputEvents()
+}
 
+const handleInputEvents = async () => {
   let digit = 0
-
-  hook.onChange((event) => {
+  for await (const event of inputs.events()) {
+    switch (event.pin) {
+      case "hook":
         const type = event.value == 0 ? "hang_up" : "pick_up"
         log.info(`📞 Hook ${event.value} sending ${type}`)
         if (type === "hang_up") {
@@ -42,24 +48,27 @@ export const startPhone = async (agentId: string, apiKey: string) => {
         } else {
           ringer.value = 0
         }
-  })
+        break
 
-  rotaryInUse.onChange((event) => {
+      case "rotaryInUse":
         if (event.value === 0) {
           digit = 0
         } else {
           log.info(`📞 Dialed digit: ${digit}`)
         }
-  })
+        break
 
-  rotaryNumber.onChange((event) => {
+      case "rotaryNumber":
         if (event.value === 1) {
           digit += 1
         }
-  })
+        break
 
-  // Keep process running
-  await new Promise(() => {})
+      default:
+        log.error(`📞 Unknown pin event: ${event.pin}`)
+        break
+    }
+  }
 }
 
 const apiKey = process.env.ELEVEN_API_KEY

src/pins/README.md

@@ -4,12 +4,11 @@ High-level GPIO library for Bun using libgpiod v2 with automatic resource manage
 
 ## Features
 
-- True event-driven GPIO with worker-based architecture (<10ms latency)
-- Zero CPU usage when idle (blocking on hardware events)
-- Type-safe TypeScript API
+- Type-safe TypeScript API with autocomplete for pin names
 - Automatic resource cleanup with `using` keyword
 - Hardware debouncing via kernel
-- Callback-based event handling with multiple listeners
+- Event-driven input handling
+- Efficient multi-pin monitoring with input groups
 - Zero external dependencies (uses Bun FFI)
 
 ## Requirements
@@ -37,13 +36,10 @@ for (let i = 0; i < 10; i++) {
 using button = gpio.input(20, { pull: "up", debounce: 10 })
 console.log(button.value)
 
-// Listen for button events with callback
-button.onChange((event) => {
+// Listen for button events
+for await (const event of button.events()) {
   console.log(event.value === 0 ? "Pressed!" : "Released")
-})
-
-// Keep process running
-await new Promise(() => {})
+}
 ```
 
 ## API
@@ -90,6 +86,27 @@ Options:
 - `debounce?: number` - Debounce period in milliseconds (default: 0)
 - `edge?: 'rising' | 'falling' | 'both'` - Edge detection (default: 'both')
 
+#### `gpio.inputGroup(config)`
+
+Monitor multiple inputs efficiently with a single file descriptor. Pin names are fully type-safe!
+
+```typescript
+using inputs = gpio.inputGroup({
+  hook: { pin: 20, pull: "up" },
+  rotary: { pin: 21, pull: "up", debounce: 1 },
+  button: { pin: 22, pull: "down" },
+})
+
+// Access individual pins (fully typed!)
+console.log(inputs.pins.hook.value)     // TypeScript knows about .hook
+console.log(inputs.pins.button.value)   // TypeScript knows about .button
+
+// Monitor all pins
+for await (const event of inputs.events()) {
+  console.log(`${event.pin}: ${event.value}`)  // event.pin is "hook" | "rotary" | "button"
+}
+```
+
 #### `gpio.listChips()`
 
 List available GPIO chips.
@@ -100,30 +117,22 @@ console.log(chips)
 // [{ path: '/dev/gpiochip0', name: 'pinctrl-bcm2835', label: '...', numLines: 58 }]
 ```
 
-### Input
+### InputPin
 
 ```typescript
 using button = gpio.input(20)
 
-// Read current state (cached from last event)
+// Read current state
 const value: 0 | 1 = button.value
 
-// Listen for changes (returns unsubscribe function)
-const unsubscribe = button.onChange((event) => {
-  console.log(event.value, event.timestamp)
-})
-
-// Add multiple listeners
-const unsub2 = button.onChange((event) => {
-  console.log("Second listener:", event.value)
-})
-
-// Remove specific listener
-unsubscribe()
-
 // Wait for specific value
 await button.waitForValue(0)        // wait for LOW
 await button.waitForValue(1, 5000)  // wait for HIGH with 5s timeout
+
+// Event stream
+for await (const event of button.events()) {
+  console.log(event.value, event.timestamp)
+}
 ```
 
 ### OutputPin
@@ -137,23 +146,29 @@ const value = led.value
 led.toggle()
 ```
 
-## Architecture
+### InputGroup
 
-### Worker-Based Event Handling
+```typescript
+using inputs = gpio.inputGroup({
+  switch: { pin: 16, pull: "up" },
+  button: { pin: 20, pull: "up", debounce: 10 }
+})
 
-Each input spawns a dedicated Web Worker that:
+// Access pins with full type safety
+inputs.pins.switch.value  // ✓ TypeScript autocomplete
+inputs.pins.button.value  // ✓ TypeScript autocomplete
 
-1. Blocks on `gpiod_line_request_wait_edge_events()` with `-1` timeout (infinite)
-2. Wakes instantly when hardware GPIO edge event occurs
-3. Reads event and posts message to main thread
-4. Main thread fires registered callbacks
+// Wait for specific pin values
+await inputs.pins.button.waitForValue(0)        // wait for button to go LOW
+await inputs.pins.switch.waitForValue(1, 3000)  // wait for switch to go HIGH with timeout
 
-**Benefits:**
-
-- **True blocking**: Zero CPU usage when idle
-- **Low latency**: <10ms response time (vs 100ms with polling)
-- **Independent inputs**: Each input has its own worker
-- **Clean shutdown**: Workers terminated on close, kernel handles GPIO cleanup
+// Monitor all pins
+for await (const event of inputs.events()) {
+  event.pin        // Type: 'switch' | 'button'
+  event.value      // Type: 0 | 1
+  event.timestamp  // Type: bigint (nanoseconds)
+}
+```
 
 ## Resource Management
 
@@ -161,24 +176,17 @@ Each input spawns a dedicated Web Worker that:
 
 ```typescript
 // Good - automatic cleanup
-using led = gpio.output(17) // Automatically released because of `using`
+{
+  using led = gpio.output(17)
   led.value = 1
-```
+} // Automatically released
 
-```typescript
-// Meh - manual cleanup required
+// Bad - manual cleanup required
 const led = gpio.output(17)
 led.value = 1
 led.close() // Must call manually
 ```
 
-```typescript
-// Bad - leaks resources
-const led = gpio.output(17)
-led.value = 1
-// Forgot to close() - resource leak!
-```
-
 ## Hardware Setup
 
 ### Pull Resistors
@@ -189,7 +197,6 @@ Pull resistors prevent floating input values when nothing is connected to the pi
 - **Pull-down + button to VCC**: When released, pin reads LOW (0). When pressed, pin reads HIGH (1).
 
 **Important:** Match your pull resistor to your wiring:
-
 - Button to ground → use `pull: "up"`
 - Button to VCC (3.3V) → use `pull: "down"`
 
@@ -245,27 +252,26 @@ import { GPIO } from "@/pins"
 
 const gpio = new GPIO()
 
-using button = gpio.input(20, { pull: "up", debounce: 10 })
-using switchInput = gpio.input(16, { pull: "up" })
+using inputs = gpio.inputGroup({
+  button: { pin: 20, pull: "up", debounce: 10 },
+  switch: { pin: 16, pull: "up" }
+})
+
 using led = gpio.output(21)
 
 // Set LED based on switch state
-led.value = switchInput.value
+if (inputs.pins.switch.value === 1) {
+  led.value = 1
+}
 
 // Toggle LED when button pressed
-button.onChange((event) => {
-  if (event.value === 0) {
+for await (const event of inputs.events()) {
+  if (event.pin === "button" && event.value === 0) {
     led.toggle()
-  }
-})
-
-// Mirror switch to LED
-switchInput.onChange((event) => {
+  } else if (event.pin === "switch") {
     led.value = event.value
-})
-
-// Keep process running
-await new Promise(() => {})
+  }
+}
 ```
 
 ### Rotary Phone Dialer
@@ -275,31 +281,18 @@ import { GPIO } from "@/pins"
 
 const gpio = new GPIO()
 
-using hook = gpio.input(27, { pull: "up", debounce: 3 })
-using rotaryInUse = gpio.input(22, { pull: "up", debounce: 3 })
-using rotaryNumber = gpio.input(23, { pull: "up", debounce: 3 })
+using inputs = gpio.inputGroup({
+  hook: { pin: 20, pull: "up" },
+  rotary: { pin: 21, pull: "up", debounce: 1 },
+})
 
-let digit = 0
-
-hook.onChange((event) => {
+for await (const event of inputs.events()) {
+  if (event.pin === "hook") {
     console.log(event.value === 0 ? "Phone picked up" : "Phone hung up")
-})
-
-rotaryInUse.onChange((event) => {
-  if (event.value === 0) {
-    digit = 0
-  } else {
-    console.log(`Dialed digit: ${digit}`)
+  } else if (event.pin === "rotary" && event.value === 0) {
+    console.log("Rotary pulse")
   }
-})
-
-rotaryNumber.onChange((event) => {
-  if (event.value === 1) {
-    digit += 1
 }
-})
-
-await new Promise(() => {})
 ```
 
 ## Troubleshooting

src/pins/gpio-helpers.ts

@@ -1,101 +0,0 @@
-import type { Pointer } from "bun:ffi"
-import { gpiod, GPIOD_LINE_DIRECTION_INPUT, GPIOD_LINE_DIRECTION_OUTPUT } from "./ffi"
-import { cstr, mapPullToLibgpiod, mapEdgeToLibgpiod } from "./utils"
-import type { PullMode, EdgeMode } from "./types"
-
-type LineRequestResult = {
-  chip: Pointer
-  request: Pointer
-}
-
-export type InputLineConfig = {
-  chipPath: string
-  offset: number
-  pull: PullMode
-  debounce: number
-  edge: EdgeMode
-}
-
-export type OutputLineConfig = {
-  chipPath: string
-  offset: number
-  initialValue: 0 | 1
-}
-
-const cleanup = (message: string): never => {
-  throw new Error(message)
-}
-
-const requestLine = (
-  chipPath: string,
-  offset: number,
-  consumer: string,
-  configureSettings: (settings: Pointer) => void
-): LineRequestResult => {
-  const chip = gpiod.gpiod_chip_open(cstr(chipPath))
-  if (!chip) cleanup("Failed to open GPIO chip")
-
-  const settings = gpiod.gpiod_line_settings_new()
-  if (!settings) {
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to create line settings")
-  }
-
-  configureSettings(settings!)
-
-  const lineConfig = gpiod.gpiod_line_config_new()
-  if (!lineConfig) {
-    gpiod.gpiod_line_settings_free(settings)
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to create line config")
-  }
-
-  const offsets = new Uint32Array([offset])
-  const ret = gpiod.gpiod_line_config_add_line_settings(lineConfig, offsets, 1, settings)
-  gpiod.gpiod_line_settings_free(settings)
-
-  if (ret !== 0) {
-    gpiod.gpiod_line_config_free(lineConfig)
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to add line settings")
-  }
-
-  const requestConfig = gpiod.gpiod_request_config_new()
-  if (!requestConfig) {
-    gpiod.gpiod_line_config_free(lineConfig)
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to create request config")
-  }
-
-  gpiod.gpiod_request_config_set_consumer(requestConfig, cstr(consumer))
-
-  const request = gpiod.gpiod_chip_request_lines(chip, requestConfig, lineConfig)
-  gpiod.gpiod_request_config_free(requestConfig)
-  gpiod.gpiod_line_config_free(lineConfig)
-
-  if (!request) {
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to request GPIO line")
-  }
-
-  return { chip: chip!, request: request! }
-}
-
-export const requestInputLine = (config: InputLineConfig): LineRequestResult => {
-  return requestLine(config.chipPath, config.offset, "bun-gpio-input", (settings) => {
-    gpiod.gpiod_line_settings_set_direction(settings, GPIOD_LINE_DIRECTION_INPUT)
-    gpiod.gpiod_line_settings_set_bias(settings, mapPullToLibgpiod(config.pull))
-    gpiod.gpiod_line_settings_set_edge_detection(settings, mapEdgeToLibgpiod(config.edge))
-
-    if (config.debounce > 0) {
-      gpiod.gpiod_line_settings_set_debounce_period_us(settings, config.debounce * 1000)
-    }
-  })
-}
-
-export const requestOutputLine = (config: OutputLineConfig): LineRequestResult => {
-  return requestLine(config.chipPath, config.offset, "bun-gpio", (settings) => {
-    gpiod.gpiod_line_settings_set_direction(settings, GPIOD_LINE_DIRECTION_OUTPUT)
-    gpiod.gpiod_line_settings_set_output_value(settings, config.initialValue)
-  })
-}

src/pins/gpio.ts

@@ -1,23 +1,157 @@
+import { ptr } from "bun:ffi"
 import { readdir } from "node:fs/promises"
-import { gpiod, cstr } from "./ffi"
-import { Output } from "./output"
-import { Input } from "./input"
-import { ChipNotFoundError } from "./errors"
-import type { OutputOptions, InputOptions, ChipInfo } from "./types"
+import { gpiod, cstr, GPIOD_LINE_DIRECTION_OUTPUT, GPIOD_LINE_DIRECTION_INPUT } from "./ffi"
+import { OutputPin } from "./output"
+import { InputPin } from "./input"
+import { InputGroup } from "./input-group"
+import { ChipNotFoundError, PinInUseError } from "./errors"
+import { mapPullToLibgpiod, mapEdgeToLibgpiod, hashInputConfig } from "./utils"
+import type { OutputOptions, InputOptions, PullMode, ChipInfo } from "./types"
 
 export class GPIO {
   #chipPath: string
+  #resetOnClose: boolean
 
-  constructor(options?: { chip?: string }) {
+  constructor(options?: { chip?: string; resetOnClose?: boolean }) {
     this.#chipPath = options?.chip ?? "/dev/gpiochip0"
+    this.#resetOnClose = options?.resetOnClose ?? false
   }
 
-  output(pin: number, options?: OutputOptions): Output {
-    return new Output(this.#chipPath, pin, options)
+  output(pin: number, options?: OutputOptions): OutputPin {
+    const initialValue = options?.initialValue ?? 0
+
+    const chip = gpiod.gpiod_chip_open(cstr(this.#chipPath))
+    if (!chip) {
+      throw new ChipNotFoundError(this.#chipPath)
     }
 
-  input(pin: number, options?: InputOptions): Input {
-    return new Input(this.#chipPath, pin, options)
+    try {
+      const reqConfig = gpiod.gpiod_request_config_new()
+      gpiod.gpiod_request_config_set_consumer(reqConfig, cstr("bun-gpio"))
+
+      const lineSettings = gpiod.gpiod_line_settings_new()
+      gpiod.gpiod_line_settings_set_direction(lineSettings, GPIOD_LINE_DIRECTION_OUTPUT)
+      gpiod.gpiod_line_settings_set_output_value(lineSettings, initialValue)
+
+      const lineConfig = gpiod.gpiod_line_config_new()
+      const offsets = new Uint32Array([pin])
+      gpiod.gpiod_line_config_add_line_settings(lineConfig, ptr(offsets), 1, lineSettings)
+
+      const request = gpiod.gpiod_chip_request_lines(chip, reqConfig, lineConfig)
+
+      gpiod.gpiod_line_settings_free(lineSettings)
+      gpiod.gpiod_line_config_free(lineConfig)
+      gpiod.gpiod_request_config_free(reqConfig)
+
+      if (!request) {
+        gpiod.gpiod_chip_close(chip)
+        throw new PinInUseError(pin)
+      }
+
+      let resetValue: 0 | 1 | undefined
+      if (this.#resetOnClose) {
+        const currentValue = gpiod.gpiod_line_request_get_value(request, pin)
+        if (currentValue === -1) {
+          console.warn(`Failed to read initial value for pin ${pin}, assuming 0`)
+          resetValue = 0
+        } else {
+          resetValue = currentValue as 0 | 1
+        }
+      }
+
+      return new OutputPin(chip, request, pin, resetValue)
+    } catch (err) {
+      gpiod.gpiod_chip_close(chip)
+      throw err
+    }
+  }
+
+  input(pin: number, options?: InputOptions): InputPin<"pin"> {
+    const group = this.inputGroup({
+      pin: { pin, ...options },
+    })
+
+    return new InputPin(group, "pin")
+  }
+
+  inputGroup<T extends Record<string, { pin: number } & InputOptions>>(
+    config: T
+  ): InputGroup<keyof T & string> {
+    const chip = gpiod.gpiod_chip_open(cstr(this.#chipPath))
+    if (!chip) {
+      throw new ChipNotFoundError(this.#chipPath)
+    }
+
+    try {
+      const reqConfig = gpiod.gpiod_request_config_new()
+      gpiod.gpiod_request_config_set_consumer(reqConfig, cstr("bun-gpio"))
+
+      const lineConfig = gpiod.gpiod_line_config_new()
+
+      const groups = new Map<
+        string,
+        Array<{ name: string; pin: number; pull: PullMode; options: InputOptions }>
+      >()
+
+      for (const [name, pinConfig] of Object.entries(config)) {
+        const pull = pinConfig.pull ?? "up"
+        const debounce = pinConfig.debounce ?? 0
+        const edge = pinConfig.edge ?? "both"
+
+        const hash = hashInputConfig(pull, debounce, edge)
+        if (!groups.has(hash)) groups.set(hash, [])
+        groups.get(hash)!.push({ name, pin: pinConfig.pin, pull, options: pinConfig })
+      }
+
+      for (const [hash, pins] of groups) {
+        const firstPin = pins[0]
+        if (!firstPin) continue
+
+        const pull = firstPin.options.pull ?? "up"
+        const debounce = firstPin.options.debounce ?? 0
+        const edge = firstPin.options.edge ?? "both"
+
+        const lineSettings = gpiod.gpiod_line_settings_new()
+        gpiod.gpiod_line_settings_set_direction(lineSettings, GPIOD_LINE_DIRECTION_INPUT)
+        gpiod.gpiod_line_settings_set_bias(lineSettings, mapPullToLibgpiod(pull))
+        gpiod.gpiod_line_settings_set_edge_detection(lineSettings, mapEdgeToLibgpiod(edge))
+        gpiod.gpiod_line_settings_set_debounce_period_us(lineSettings, debounce * 1000)
+
+        const offsets = new Uint32Array(pins.map((p) => p.pin))
+        gpiod.gpiod_line_config_add_line_settings(
+          lineConfig,
+          ptr(offsets),
+          pins.length,
+          lineSettings
+        )
+
+        gpiod.gpiod_line_settings_free(lineSettings)
+      }
+
+      const request = gpiod.gpiod_chip_request_lines(chip, reqConfig, lineConfig)
+
+      gpiod.gpiod_line_config_free(lineConfig)
+      gpiod.gpiod_request_config_free(reqConfig)
+
+      if (!request) {
+        gpiod.gpiod_chip_close(chip)
+        const firstConfig = Object.values(config)[0]
+        throw new PinInUseError(firstConfig?.pin ?? 0)
+      }
+
+      const pinMap: Record<string, { offset: number; pull: PullMode }> = {}
+      for (const [name, pinConfig] of Object.entries(config)) {
+        pinMap[name] = {
+          offset: pinConfig.pin,
+          pull: pinConfig.pull ?? "up",
+        }
+      }
+
+      return new InputGroup(chip, request, pinMap)
+    } catch (err) {
+      gpiod.gpiod_chip_close(chip)
+      throw err
+    }
   }
 
   async listChips(): Promise<ChipInfo[]> {

src/pins/input-group.ts

@@ -0,0 +1,205 @@
+import type { Pointer } from "bun:ffi"
+import { gpiod } from "./ffi"
+import { mapLibgpiodEdgeToPressedState } from "./utils"
+import type { PullMode, InputEvent, InputGroupEvent, PinConfig } from "./types"
+
+export class InputGroup<T extends string = string> {
+  #closed = false
+  #chip: Pointer
+  #request: Pointer
+  #pinMap: Map<string, { offset: number; pull: PullMode }>
+  #offsetMap: Map<number, { name: string; pull: PullMode }>
+  #eventBuffer: Pointer | undefined
+  #eventListeners: Array<(event: InputGroupEvent<T>) => void> = []
+  #closeHandlers: Array<() => void> = []
+
+  constructor(chip: Pointer, request: Pointer, pinConfig: PinConfig) {
+    this.#chip = chip
+    this.#request = request
+
+    this.#pinMap = new Map()
+    this.#offsetMap = new Map()
+
+    for (const [name, config] of Object.entries(pinConfig)) {
+      this.#pinMap.set(name, config)
+      this.#offsetMap.set(config.offset, { name, pull: config.pull })
+    }
+  }
+
+  get pins(): Record<
+    T,
+    { readonly value: 0 | 1; waitForValue: (targetValue: 0 | 1, timeout?: number) => Promise<void> }
+  > {
+    const result = {} as Record<
+      T,
+      {
+        readonly value: 0 | 1
+        waitForValue: (targetValue: 0 | 1, timeout?: number) => Promise<void>
+      }
+    >
+
+    for (const [name, config] of this.#pinMap) {
+      const offset = config.offset
+      const closed = () => this.#closed
+      const request = this.#request
+      const pinName = name
+
+      Object.defineProperty(result, name, {
+        get: () => ({
+          get value(): 0 | 1 {
+            if (closed()) throw new Error("InputGroup is closed")
+            const ret = gpiod.gpiod_line_request_get_value(request, offset)
+            if (ret === -1) throw new Error("Failed to get pin value")
+            return ret as 0 | 1
+          },
+          waitForValue: (targetValue: 0 | 1, timeout?: number) =>
+            this.#waitForPinValue(pinName as T, targetValue, timeout),
+        }),
+        enumerable: true,
+      })
+    }
+
+    return result
+  }
+
+  async #waitForPinValue(pinName: T, targetValue: 0 | 1, timeout?: number): Promise<void> {
+    return new Promise((resolve, reject) => {
+      if (this.#closed) {
+        reject(new Error("InputGroup is closed"))
+        return
+      }
+
+      let timeoutId: ReturnType<typeof setTimeout> | undefined
+
+      const cleanup = () => {
+        if (timeoutId) clearTimeout(timeoutId)
+        this.#eventListeners = this.#eventListeners.filter((l) => l !== listener)
+        this.#closeHandlers = this.#closeHandlers.filter((h) => h !== onClose)
+      }
+
+      const onClose = () => {
+        cleanup()
+        reject(new Error("InputGroup closed while waiting"))
+      }
+
+      const listener = (event: InputGroupEvent<T>) => {
+        if (event.pin !== pinName) return
+        if (event.value !== targetValue) return
+
+        cleanup()
+        resolve()
+      }
+
+      if (timeout) {
+        timeoutId = setTimeout(() => {
+          cleanup()
+          reject(new Error(`Timeout waiting for pin ${pinName} to become ${targetValue}`))
+        }, timeout)
+      }
+
+      this.#eventListeners.push(listener)
+      this.#closeHandlers.push(onClose)
+      this.#startEventLoop()
+    })
+  }
+
+  async *events(): AsyncGenerator<InputGroupEvent<T>> {
+    if (this.#closed) throw new Error("InputGroup is closed")
+
+    const eventQueue: InputGroupEvent<T>[] = []
+    const listener = (event: InputGroupEvent<T>) => {
+      eventQueue.push(event)
+    }
+
+    this.#eventListeners.push(listener)
+    this.#startEventLoop()
+
+    try {
+      while (!this.#closed) {
+        if (eventQueue.length > 0) {
+          for (const event of eventQueue) {
+            yield event
+          }
+          eventQueue.length = 0
+        } else {
+          await Bun.sleep(0)
+        }
+      }
+    } finally {
+      this.#eventListeners = this.#eventListeners.filter((l) => l !== listener)
+    }
+  }
+
+  #startEventLoop() {
+    if (this.#eventBuffer !== undefined) return
+
+    const buffer = gpiod.gpiod_edge_event_buffer_new(1)
+    if (!buffer) throw new Error("Failed to create event buffer")
+
+    this.#eventBuffer = buffer
+    this.#runEventLoop()
+  }
+
+  async #runEventLoop() {
+    try {
+      while (!this.#closed && this.#eventListeners.length > 0) {
+        const ret = gpiod.gpiod_line_request_wait_edge_events(this.#request, 100_000_000)
+
+        if (ret === -1 || ret === 0) {
+          await Bun.sleep(0)
+          continue
+        }
+
+        const numEvents = gpiod.gpiod_line_request_read_edge_events(
+          this.#request,
+          this.#eventBuffer!,
+          1
+        )
+
+        if (numEvents > 0) {
+          const event = gpiod.gpiod_edge_event_buffer_get_event(this.#eventBuffer!, 0)
+          const edgeType = gpiod.gpiod_edge_event_get_event_type(event)
+          const timestamp = gpiod.gpiod_edge_event_get_timestamp_ns(event)
+          const offset = gpiod.gpiod_edge_event_get_line_offset(event)
+
+          const pinInfo = this.#offsetMap.get(offset)
+          if (!pinInfo) continue
+
+          const pressed = mapLibgpiodEdgeToPressedState(edgeType, pinInfo.pull)
+          const value = (
+            pressed ? (pinInfo.pull === "up" ? 0 : 1) : pinInfo.pull === "up" ? 1 : 0
+          ) as 0 | 1
+          const inputEvent: InputGroupEvent<T> = { pin: pinInfo.name as T, value, timestamp }
+
+          for (const listener of this.#eventListeners) {
+            listener(inputEvent)
+          }
+
+          await Bun.sleep(0)
+        }
+      }
+    } finally {
+      if (this.#eventBuffer) {
+        gpiod.gpiod_edge_event_buffer_free(this.#eventBuffer)
+        this.#eventBuffer = undefined
+      }
+    }
+  }
+
+  close() {
+    if (this.#closed) return
+    this.#closed = true
+
+    for (const handler of this.#closeHandlers) {
+      handler()
+    }
+    this.#closeHandlers = []
+
+    gpiod.gpiod_line_request_release(this.#request)
+    gpiod.gpiod_chip_close(this.#chip)
+  }
+
+  [Symbol.dispose]() {
+    this.close()
+  }
+}

src/pins/input-worker.ts

@@ -1,84 +0,0 @@
-import { gpiod, GPIOD_EDGE_EVENT_RISING_EDGE } from "./ffi"
-import { requestInputLine } from "./gpio-helpers"
-import type { PullMode, EdgeMode } from "./types"
-
-type WorkerConfig = {
-  chipPath: string
-  offset: number
-  pull: PullMode
-  debounce: number
-  edge: EdgeMode
-}
-
-type WorkerMessage =
-  | { type: "ready"; initialValue: 0 | 1 }
-  | { type: "event"; value: 0 | 1; timestamp: bigint }
-  | { type: "error"; message: string }
-
-const postMessage = (message: WorkerMessage) => {
-  self.postMessage(message)
-}
-
-const cleanup = (message: string): never => {
-  postMessage({ type: "error", message })
-  self.close()
-  throw new Error(message)
-}
-
-const mapEdgeToValue = (edgeType: number, pull: PullMode): 0 | 1 => {
-  // Pull-up: rising edge = released (1), falling edge = pressed (0)
-  // Pull-down: rising edge = pressed (1), falling edge = released (0)
-  if (pull === "up") {
-    return edgeType === GPIOD_EDGE_EVENT_RISING_EDGE ? 1 : 0
-  }
-  return edgeType === GPIOD_EDGE_EVENT_RISING_EDGE ? 1 : 0
-}
-
-const run = (config: WorkerConfig) => {
-  const { chip, request } = requestInputLine(config)
-
-  const initialValue = gpiod.gpiod_line_request_get_value(request, config.offset)
-  if (initialValue === -1) {
-    gpiod.gpiod_line_request_release(request)
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to read initial value")
-  }
-
-  postMessage({ type: "ready", initialValue: initialValue as 0 | 1 })
-
-  const buffer = gpiod.gpiod_edge_event_buffer_new(1)
-  if (!buffer) {
-    gpiod.gpiod_line_request_release(request)
-    gpiod.gpiod_chip_close(chip)
-    cleanup("Failed to create event buffer")
-  }
-
-  while (true) {
-    // Block forever (-1 timeout) until edge event occurs
-    const waitResult = gpiod.gpiod_line_request_wait_edge_events(request, -1)
-
-    if (waitResult === 1) {
-      const numEvents = gpiod.gpiod_line_request_read_edge_events(request, buffer, 1)
-      if (numEvents === -1) cleanup("Failed to read edge events")
-
-      const event = gpiod.gpiod_edge_event_buffer_get_event(buffer, 0)
-      const edgeType = gpiod.gpiod_edge_event_get_event_type(event)
-      const timestamp = gpiod.gpiod_edge_event_get_timestamp_ns(event)
-
-      const value = mapEdgeToValue(edgeType, config.pull)
-
-      postMessage({ type: "event", value, timestamp })
-    } else if (waitResult === -1) {
-      cleanup("GPIO wait_edge_events failed")
-    }
-  }
-
-  // Worker terminates - kernel cleans up GPIO resources automatically
-}
-
-self.onmessage = (event: MessageEvent<WorkerConfig>) => {
-  self.onmessage = () => {
-    throw new Error("Worker already initialized")
-  }
-  run(event.data)
-}

src/pins/input.ts

@@ -1,90 +1,36 @@
-import type { InputEvent, InputOptions } from "./types"
+import type { Pointer } from "bun:ffi"
+import { InputGroup } from "./input-group"
+import type { PullMode, InputEvent } from "./types"
 
-type WorkerMessage =
-  | { type: "ready"; initialValue: 0 | 1 }
-  | { type: "event"; value: 0 | 1; timestamp: bigint }
-  | { type: "error"; message: string }
+export class InputPin<T extends string = string> {
+  #group: InputGroup<T>
+  #pinName: T
 
-export class Input {
-  #worker: Worker
-  #callbacks = new Set<(event: InputEvent) => void>()
-  #closed = false
-  #lastValue: 0 | 1 = 0
-
-  constructor(chipPath: string, offset: number, options: InputOptions = {}) {
-    const pull = options.pull ?? "up"
-    const debounce = options.debounce ?? 0
-    const edge = options.edge ?? "both"
-
-    this.#worker = new Worker(new URL("./input-worker.ts", import.meta.url).href)
-
-    this.#worker.onmessage = (msg: MessageEvent<WorkerMessage>) => {
-      if (this.#closed) return
-
-      const data = msg.data
-
-      if (data.type === "ready") {
-        this.#lastValue = data.initialValue
-      } else if (data.type === "event") {
-        this.#lastValue = data.value
-        for (const callback of this.#callbacks) {
-          callback({ value: data.value, timestamp: data.timestamp })
-        }
-      } else if (data.type === "error") {
-        console.error(`GPIO Input Error (pin ${offset}):`, data.message)
-      }
-    }
-
-    this.#worker.postMessage({ chipPath, offset, pull, debounce, edge })
+  constructor(group: InputGroup<T>, pinName: T) {
+    this.#group = group
+    this.#pinName = pinName
   }
 
   get value(): 0 | 1 {
-    if (this.#closed) throw new Error("Input is closed")
-    return this.#lastValue
-  }
-
-  onChange(callback: (event: InputEvent) => void): () => void {
-    if (this.#closed) throw new Error("Input is closed")
-    this.#callbacks.add(callback)
-    return () => this.#callbacks.delete(callback)
+    return this.#group.pins[this.#pinName]!.value
   }
 
   async waitForValue(targetValue: 0 | 1, timeout?: number): Promise<void> {
-    if (this.#closed) throw new Error("Input is closed")
-
-    if (this.#lastValue === targetValue) return
-
-    return new Promise((resolve, reject) => {
-      let timeoutId: ReturnType<typeof setTimeout> | undefined
-
-      const cleanup = () => {
-        if (timeoutId) clearTimeout(timeoutId)
-        unsubscribe()
-      }
-
-      const unsubscribe = this.onChange((event) => {
+    for await (const event of this.#group.events()) {
       if (event.value === targetValue) {
-          cleanup()
-          resolve()
+        return
+      }
+    }
   }
-      })
 
-      if (!timeout) return
-
-      timeoutId = setTimeout(() => {
-        cleanup()
-        reject(new Error(`Timeout waiting for value ${targetValue}`))
-      }, timeout)
-    })
+  async *events(): AsyncGenerator<InputEvent> {
+    for await (const event of this.#group.events()) {
+      yield { value: event.value, timestamp: event.timestamp }
+    }
   }
 
   close() {
-    if (this.#closed) return
-    this.#closed = true
-
-    this.#callbacks.clear()
-    this.#worker.onmessage = null
-    this.#worker.terminate()
+    this.#group.close()
   }
 
   [Symbol.dispose]() {

src/pins/output.ts

@@ -1,39 +1,30 @@
 import type { Pointer } from "bun:ffi"
 import { gpiod } from "./ffi"
-import { requestOutputLine } from "./gpio-helpers"
-import type { OutputOptions } from "./types"
 
-export class Output {
+export class OutputPin {
   #closed = false
   #chip: Pointer
   #request: Pointer
-  #offset: number
+  #pin: number
   #resetValue?: 0 | 1
 
-  constructor(chipPath: string, offset: number, options: OutputOptions = {}) {
-    const initialValue = options.initialValue ?? 0
-    const { chip, request } = requestOutputLine({ chipPath, offset, initialValue })
-
+  constructor(chip: Pointer, request: Pointer, pin: number, resetValue?: 0 | 1) {
     this.#chip = chip
     this.#request = request
-    this.#offset = offset
-
-    if (options.resetOnClose) {
-      const currentValue = gpiod.gpiod_line_request_get_value(request, offset)
-      this.#resetValue = currentValue === -1 ? 0 : (currentValue as 0 | 1)
-    }
+    this.#pin = pin
+    this.#resetValue = resetValue
   }
 
   get value(): 0 | 1 {
-    if (this.#closed) throw new Error("Output is closed")
-    const ret = gpiod.gpiod_line_request_get_value(this.#request, this.#offset)
+    if (this.#closed) throw new Error("OutputPin is closed")
+    const ret = gpiod.gpiod_line_request_get_value(this.#request, this.#pin)
     if (ret === -1) throw new Error("Failed to get pin value")
     return ret as 0 | 1
   }
 
   set value(val: 0 | 1) {
-    if (this.#closed) throw new Error("Output is closed")
-    const ret = gpiod.gpiod_line_request_set_value(this.#request, this.#offset, val)
+    if (this.#closed) throw new Error("OutputPin is closed")
+    const ret = gpiod.gpiod_line_request_set_value(this.#request, this.#pin, val)
     if (ret === -1) throw new Error("Failed to set pin value")
   }
 
@@ -46,7 +37,7 @@ export class Output {
     this.#closed = true
 
     if (this.#resetValue !== undefined) {
-      gpiod.gpiod_line_request_set_value(this.#request, this.#offset, this.#resetValue)
+      gpiod.gpiod_line_request_set_value(this.#request, this.#pin, this.#resetValue)
     }
 
     gpiod.gpiod_line_request_release(this.#request)

src/pins/tsconfig.worker.json

@@ -1,7 +0,0 @@
-{
-  "extends": "../../tsconfig.json",
-  "compilerOptions": {
-    "lib": ["ESNext", "WebWorker"]
-  },
-  "include": ["input-worker.ts"]
-}

src/pins/types.ts

@@ -9,7 +9,6 @@ export type InputOptions = {
 
 export type OutputOptions = {
   initialValue?: 0 | 1 // default: 0
-  resetOnClose?: boolean // default: false
 }
 
 export type InputEvent = {

src/pins/utils.ts

@@ -38,7 +38,10 @@ export const mapEdgeToLibgpiod = (edge: EdgeMode): number => {
 // Hardware logic:
 // - Pull-up + button to GND: pressing pulls line LOW (falling edge = pressed)
 // - Pull-down + button to VCC: pressing pulls line HIGH (rising edge = pressed)
-export const mapLibgpiodEdgeToPressedState = (edgeType: number, pull: PullMode): boolean => {
+export const mapLibgpiodEdgeToPressedState = (
+  edgeType: number,
+  pull: PullMode
+): boolean => {
   if (pull === "up") {
     return edgeType === GPIOD_EDGE_EVENT_FALLING_EDGE
   } else if (pull === "down") {
@@ -48,6 +51,10 @@ export const mapLibgpiodEdgeToPressedState = (edgeType: number, pull: PullMode):
   }
 }
 
-export const hashInputConfig = (pull: PullMode, debounce: number, edge: EdgeMode): string => {
+export const hashInputConfig = (
+  pull: PullMode,
+  debounce: number,
+  edge: EdgeMode
+): string => {
   return `${pull}-${debounce}-${edge}`
 }

src/test-pins.ts

@@ -2,38 +2,45 @@ import { GPIO } from "./pins"
 
 console.log(`kill -9 ${process.pid}`)
 
-const gpio = new GPIO()
+const gpio = new GPIO({ resetOnClose: true })
 
+// // Blink an LED
 using led = gpio.output(21)
-using button = gpio.input(20, { pull: "up", debounce: 10 })
-using switchInput = gpio.input(16, { pull: "up", debounce: 10 })
 
-led.value = button.value
+// Read a button
+using inputs = gpio.inputGroup({
+  button: { pin: 20, pull: "up", debounce: 10 },
+  switch: { pin: 16, pull: "up", debounce: 10 }
+})
 
-button.onChange((event) => {
+led.value = inputs.pins.button.value
+
+const iteratorEvents = new Promise(async (resolve) => {
+  for await (const event of inputs.events()) {
+    if (event.pin === "button") {
       led.value = event.value
+    }
+  }
 })
 
 const switchEvent = new Promise<void>(async (resolve) => {
-  await switchInput.waitForValue(0)
+  await inputs.pins.switch.waitForValue(0)
   console.log("Switch pressed!")
   resolve()
 })
 
 process.on("SIGINT", () => {
-  button.close()
-  switchInput.close()
+  inputs.close()
   led.close()
   process.exit(0)
 })
 
 process.on("SIGTERM", () => {
-  button.close()
-  switchInput.close()
-  led.close()
+  inputs.close()
+  
   process.exit(0)
 })
 
-await switchEvent
+await Promise.race([iteratorEvents, switchEvent])
 
 console.log(`👋 Goodbye!`)

tsconfig.json

@@ -26,6 +26,5 @@
     "noUnusedLocals": false,
     "noUnusedParameters": false,
     "noPropertyAccessFromIndexSignature": false
-  },
-  "exclude": ["src/pins/input-worker.ts"]
+  }
 }