Variable pca9685Const

Type Declaration

• channels: number

  How many channels it drives.

• counts: number

  How many counts each period is divided into.

• defaultAddress: number

  The address it answers at with its six address pins low.

• internalOscHz: number

  The part's internal oscillator frequency, in hertz.

• mode1: { autoIncrement: number; extclk: number; restart: number; sleep: number }

  MODE1's bits.

  • autoIncrement: number

    The register pointer moves on after each byte.

  • extclk: number

    The prescaler divides the EXTCLK pin rather than the oscillator.

  • restart: number

    Set when the part slept with a channel running; cleared by a written 1.

  • sleep: number

    The oscillator is off and PRE_SCALE takes a write.

• mode1Reset: number

  MODE1 at power-up: asleep, answering the All Call address.

• mode2Reset: number

  MODE2 at power-up: totem-pole outputs.

• oscillatorStartupMicros: number

  How long the oscillator takes to run once woken, in microseconds.

• preScaleMin: number

  The smallest value the part loads into PRE_SCALE.

• preScaleReset: number

  PRE_SCALE at power-up: 200 Hz on the internal oscillator.

• register: {
      allLedOnL: number;
      led0OnL: number;
      mode1: number;
      mode2: number;
      preScale: number;
  }

  The registers a driver writes and a program reads back.

  • allLedOnL: number

    The first of the four registers that load every channel at once.

  • led0OnL: number

    The first of channel 0's four registers; channelRegister gives the rest.

  • mode1: number

    Mode register 1: restart, clock, auto-increment, sleep, and the addresses answered.

  • mode2: number

    Mode register 2: how the outputs are wired and when they change.

  • preScale: number

    The prescaler, writable only while the part sleeps.

• sim: { part(address?: number): hal.I2cPart }

  A PCA9685 that is not there. It holds the part's power-on registers and keeps its datasheet's rules: PRE_SCALE takes a write only while the part sleeps, the register pointer moves on only with auto-increment set, and one write to the ALL_LED registers loads every channel.

  • part: function

    • part(address?: number): hal.I2cPart

      A simulated PCA9685 as it powers up: asleep at 200 Hz with every output off.

      Parameters

      • Optionaladdress: number

        The address it answers to, defaultAddress unless given.

      Returns hal.I2cPart

      A part to put on a simulated bus.

• channelRegister: function

  • channelRegister(channel: number): number

    Returns the first of a channel's four consecutive registers.

    Parameters

    • channel: number

      The channel, 0 to 15.

    Returns number

    The register address.

    Throws

    If the channel is beyond the part.

• frequencyForPrescale: function

  • frequencyForPrescale(prescale: number, oscHz?: number): number

    Returns the update rate a prescale value produces.

    Parameters

    • prescale: number

      The prescale register value.

    • OptionaloscHz: number

      The oscillator frequency, usually internalOscHz.

    Returns number

    The frequency in hertz.

• prescaleForFrequency: function

  • prescaleForFrequency(updateRateHz: number, oscHz?: number): number

    Returns the prescale value that sets an update rate.

    Parameters

    • updateRateHz: number

      The PWM frequency wanted.

    • OptionaloscHz: number

      The oscillator frequency, usually internalOscHz.

    Returns number

    The prescale register value.