PCA9685 Comprehensive Test Suite

The pca9685_comprehensive_test application runs a full set of tests against the PCA9685 driver and hardware. Use it to verify wiring, I2C address, and all driver features.

What It Tests

Test Sections (12 tasks total)

  1. Initialization
    • i2c_bus_initialization: I2C bus init (SDA/SCL, 100 kHz).
    • driver_initialization: Driver creation and Reset().
  2. Frequency
    • pwm_frequency: Set 50, 100, 200, 500, 1000 Hz; check invalid 10 Hz / 2000 Hz handling.
  3. PWM
    • channel_pwm: Set 50% duty on each of the 16 channels.
  4. Duty cycle
    • duty_cycle: Sweep duty on all channels; clamp test (negative / >1.0).
    • all_channel_control: SetAllPwm, SetChannelFullOn, SetChannelFullOff on all 16.
    • prescale_readback: Set frequency, read prescale, verify (50, 200, 1000, 24, 1526 Hz).
    • sleep_wake: Sleep() / Wake() and PWM after wake; 5 sleep/wake cycles.
    • output_config: SetOutputInvert, SetOutputDriverMode (totem-pole / open-drain).
  5. Error handling
    • error_handling: Invalid channel (255), invalid PWM (5000), invalid frequency (5 Hz); GetLastError, ClearError, HasAnyError.
  6. Stress
    • stress_rapid_writes: Many back-to-back SetDuty and SetAllPwm and frequency changes.
    • stress_boundary_values: Min/max/staggered PWM on all channels; FullOn to FullOff to PWM; 5 reset cycles.

I2C bus scan

If the first attempt to connect to the PCA9685 at the configured address fails, the app runs an I2C bus scan (all 0x08 to 0x77) and logs which addresses respond. Use this to confirm the device address and bus.

Source and Configuration

  • Source: main/pca9685_comprehensive_test.cpp
  • I2C bus: main/esp32_pca9685_bus.hpp (default SDA=GPIO4, SCL=GPIO5, 100 kHz)
  • Address: PCA9685_I2C_ADDRESS (default 0x40)
  • Sections: Enable/disable via ENABLE_*_TESTS defines at the top of the test file.

Build and Run

From examples/esp32:

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./scripts/build_app.sh pca9685_comprehensive_test Debug
./scripts/flash_app.sh flash_monitor pca9685_comprehensive_test Debug

Expected: all 12 tests pass, summary shows Total: 12, Passed: 12, Failed: 0. GPIO14 is used as a progress indicator.

Customization

  • I2C pins: Build with CMake override, e.g.
    -DPCA9685_EXAMPLE_I2C_SDA_GPIO=8 -DPCA9685_EXAMPLE_I2C_SCL_GPIO=9
  • Address: Change PCA9685_I2C_ADDRESS in the test file to match A0 to A5.
  • Sections: Set ENABLE_*_TESTS to false to skip a section.

Relation to the API

The test exercises the public API as in the main docs API reference:

  • Init: EnsureInitialized(), Reset(), IsInitialized()
  • Frequency: SetPwmFreq(), GetPrescale()
  • PWM: SetPwm(), SetDuty(), SetAllPwm(), SetChannelFullOn(), SetChannelFullOff()
  • Power: Sleep(), Wake()
  • Output: SetOutputInvert(), SetOutputDriverMode()
  • Errors: GetLastError(), GetErrorFlags(), HasError(), HasAnyError(), ClearError(), ClearErrorFlags()

See ../../../docs/api_reference.md for full method list.