發送短信 : On-off-keying communication system based on low power receiver

  _  _     ______               ___      _____   
 | \| ||  /_   _//   ____      / _ \\   |__  //  
 |  ' ||   -| ||-   |    \\   | / \ ||    / //   
 | .  ||   _| ||_   | [] ||   | \_/ ||   / //__  
 |_|\_||  /_____//  |  __//    \___//   /_____|| 
 `-` -`   `-----`   |_|`-`     `---`    `-----`  
                    `-`