allwpilib/hal/src/main/native/systemcore/SmartIo.cpp

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

#include "SmartIo.h"

#include <atomic>

#include "HALInitializer.h"
#include "SystemServer.h"

namespace hal {

wpi::mutex smartIoMutex;
DigitalHandleResource<HAL_DigitalHandle, SmartIo, kNumSmartIo>* smartIoHandles;

namespace init {
void InitializeSmartIo() {
  static DigitalHandleResource<HAL_DigitalHandle, SmartIo, kNumSmartIo> dcH;
  smartIoHandles = &dcH;
}
}  // namespace init

int32_t SmartIo::InitializeMode(SmartIoMode mode) {
  auto inst = hal::GetSystemServer();

  nt::PubSubOptions options;
  options.sendAll = true;
  options.keepDuplicates = true;
  options.periodic = 0.005;

  auto channelString = std::to_string(channel);

  modePublisher = inst.GetDoubleTopic("/io/type" + channelString).Publish();
  getSubscriber = inst.GetDoubleTopic("/io/valread" + channelString)
                      .Subscribe(0.0, options);

  currentMode = mode;
  switch (mode) {
    case SmartIoMode::PWMOutput:
      modePublisher.Set(3);
      setPublisher =
          inst.GetDoubleTopic("/io/valset" + channelString).Publish(options);
      setPublisher.Set(0);
      pwmMinPublisher =
          inst.GetDoubleTopic("/io/pwmmin" + channelString).Publish();
      pwmMinPublisher.Set(0);
      pwmMaxPublisher =
          inst.GetDoubleTopic("/io/pwmmax" + channelString).Publish();
      pwmMaxPublisher.Set(4096);
      return 0;

    default:

      return INCOMPATIBLE_STATE;
  }
}

int32_t SmartIo::SetPwmMicroseconds(uint16_t microseconds) {
  if (currentMode != SmartIoMode::PWMOutput) {
    return INCOMPATIBLE_STATE;
  }

  // TODO(thad) add support for always on signal

  if (microseconds > 4095) {
    microseconds = 4095;
  }

  // Scale from 0-4096 to 0.0-2.0, then to -1.0-1.0
  setPublisher.Set((microseconds / 2048.0) - 1);

  return 0;
}

int32_t SmartIo::GetPwmMicroseconds(uint16_t* microseconds) {
  if (currentMode != SmartIoMode::PWMOutput) {
    return INCOMPATIBLE_STATE;
  }

  double val = getSubscriber.Get();

  // Get to 0-2, then scale to 0-4096;
  *microseconds = (val + 1) * 2048;

  return 0;
}

}  // namespace hal