【九联科技Unionpi Tiger开发板试用体验】ROS noteic 实时读取ZE08-CH2O

1. 重烧镜像

参照上一个贴子操作

镜像地址：
链接: https://pan.baidu.com/s/1roXNRNPnhH5S7uVqFkEwng?pwd=8k6t
提取码: 8k6t
Ubuntu-20.04.4-LTS-5.18

2. 更改两个配置

1、resize2fs根文件系统
$ sudo resize2fs /dev/system
2、串口终端输入，需修改console为ttyAML0，完整命令如下（Ctrl+C进入uboot后修改环境变量）
$ setenv initargs 'rootfstype=ext4 rw root=/dev/mmcblk0p16 init=/sbin/init console=ttyAML0,115200 no_console_suspend earlycon=meson,0xff803000 ramoops.pstore_en=1 ramoops.record_size=0x8000 ramoops.console_size=0x4000 skip_initramfs'
$ save

3. 硬件连接

4. 部分软件代码

uint8_t FormaldehydeUart::check_sum(uint8_t *data, uint8_t len)
{
  uint8_t tmp = 0;
  for(int j = 1; j < len - 1; j++)
  {
    tmp += data[j];
  }
  return (~tmp + 1);
}

bool FormaldehydeUart::is_check_sum(uint8_t *data, uint8_t len)
{
  if(check_sum(data, len) == data[len - 1])
  {
    return true;
  }
  return false;
}

void FormaldehydeUart::update(void)
{
  ros::Rate r(5);
  while (ros::ok())
  {
  if (serial_->isOpen())
  {
    uint8_t read_buffer[read_buffer_size];

    size_t n = serial_->available();

    if ( n != 0)
    {
      serial_->read(read_buffer, read_buffer_size);
      if(!is_check_sum(read_buffer, read_buffer_size))
      {
      	continue;
      }
      uint16_t formaldehyde;
      formaldehyde = ((uint16_t)read_buffer[4] << 8)| read_buffer[5];
      std_msgs::Float64 msg;
      //ROS_INFO_STREAM("formaldehyde: " << formaldehyde);
      msg.data = (double)formaldehyde/1000.0;//*1.25;
      formaldehyde_pub_.publish(msg);
    }
  }
  else
  {
    int max_count = output_hz_ * 5;
    open_count_++;
    if (open_count_ >= max_count)
    {
      open_count_ = 0;
      try
      {
        serial_->open();
      }
      catch (std::exception &e)
      {
        ROS_WARN("open serial port failed");
      }
    }
  }
  updateDiagnostics();
  	r.sleep();
  }
}

5. 启动ROS

$ roscore
$ rosrun

6. 获取甲醛值