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bcb3ab5dd8
This commit adds interrupt-based GPIO expander support to eliminate continuous
polling and significantly reduce I2C/SPI traffic and CPU usage.
## Key Changes
### Core Infrastructure (gpio_expander/cached_gpio.h)
- Extended CachedGpioExpander base class with interrupt pin support
- Added setup_interrupt_pin() method to attach native GPIO interrupt handlers
- Implemented interrupt-driven cache management:
- ISR sets flag and enables component loop when interrupt fires
- process_interrupt_() reads chip-specific interrupt status registers
- Cache remains valid between interrupts (no polling)
- Component loop automatically disabled until next interrupt
- Added virtual read_interrupt_status_() for chip-specific implementations
- Maintains backward compatibility: interrupt_pin is optional, defaults to polling
### MCP23xxx Family Support
- MCP23x17 (16-pin): Added INTF/INTCAP register reading
- MCP23x08 (8-pin): Added INTF/INTCAP register reading
- Configured IOCON register for interrupt mirroring (INTA=INTB)
- Combined with existing open_drain_ints support
- Chips: MCP23017, MCP23008, MCP23S17, MCP23S08
### PI4IOE5V6408 Support
- Implemented interrupt status register (0x13) reading
- Reads input state register (0x0F) to capture values and clear interrupt
- Single 8-pin bank design
### Python Configuration
- Added CONF_INTERRUPT_PIN to component schemas
- Uses pins.internal_gpio_input_pin_schema for validation
- Optional configuration maintains full backward compatibility
- Example:
```yaml
mcp23017:
id: my_expander
interrupt_pin: GPIO5 # Connect to INTA/INTB
binary_sensor:
- platform: gpio
pin:
mcp23xxx: my_expander
number: 0
interrupt: CHANGE # Existing config, now uses hardware interrupt
```
### Testing
- Updated component test configurations
- Added interrupt_pin test cases for both MCP23017 and PI4IOE5V6408
- Tests both polling mode (no interrupt_pin) and interrupt mode
## Benefits
| Aspect | Before (Polling) | After (Interrupts) |
|----------------|------------------|-------------------|
| I2C Reads | 60-120/sec | 2 per state change|
| CPU Usage | Continuous loop | ISR + event-driven|
| Latency | ~16ms (loop) | <1ms (ISR) |
| Power | Higher | Lower (sleep) |
## Implementation Details
**Interrupt Flow:**
1. Setup: Native GPIO interrupt attached to INTA/INTB pin (FALLING edge)
2. ISR: Sets pending flag, calls enable_loop_soon_any_context()
3. Loop: Reads interrupt status register to identify changed pins
4. Cache: Updates only changed pins, keeps cache valid
5. Optimization: Calls disable_loop() until next interrupt
**Safety:**
- Uses volatile bool for interrupt_pending_ flag
- IRAM_ATTR on ISR for fast execution
- Gracefully falls back to polling if interrupt_pin not configured
- No changes required to binary_sensor platform code
## Backward Compatibility
✅ Existing configurations work unchanged (polling mode)
✅ interrupt_pin is optional - add when ready
✅ No breaking changes to any APIs
✅ Binary sensors automatically benefit from interrupt efficiency
Addresses the need for efficient GPIO expander operation by eliminating
unnecessary continuous polling when hardware interrupts are available.
Tests for ESPHome
This directory contains some tests for ESPHome.
At the moment, all the tests only work by simply executing
esphome over some YAML files that are made to test
whether the yaml gets converted to the proper C++ code.
Of course this is all just very high-level and things like unit tests would be much better. So if you have time and know how to set up a unit testing framework for python, please do give it a try.
When adding entries in test_.yaml files we usually need only
one file updated, unless conflicting code is generated for
different configurations, e.g. wifi and ethernet cannot
be tested on the same device.
Current test_.yaml file contents.
| Test name | Platform | Network | BLE |
|---|---|---|---|
| test1.yaml | ESP32 | wifi | None |
| test2.yaml | ESP32 | ethernet | esp32_ble_tracker |
| test3.yaml | ESP8266 | wifi | N/A |
| test4.yaml | ESP32 | ethernet | None |
| test5.yaml | ESP32 | wifi | ble_server |
| test6.yaml | RP2040 | wifi | N/A |
| test7.yaml | ESP32-C3 | wifi | N/A |
| test8.yaml | ESP32-S3 | wifi | None |
| test10.yaml | ESP32 | wifi | None |