File content as of revision 0:07a5cc567526:

#include "mbed.h"
#include "BufferedSerial.h"


#define GET_LOW_char(A) (uint8_t)((A))
//Macro function  get lower 8 bits of A
#define GET_HIGH_char(A) (uint8_t)((A) >> 8)
//Macro function  get higher 8 bits of A
#define char_TO_HW(A, B) ((((uint16_t)(A)) << 8) | (uint8_t)(B))
//put A as higher 8 bits   B as lower 8 bits   which amalgamated into 16 bits integer
#define ID1 1
#define ID2 2
#define ID3 3
#define ID4 4

#define LOBOT_SERVO_FRAME_HEADER         0x55
#define LOBOT_SERVO_MOVE_TIME_WRITE      1

using namespace std;

BufferedSerial serial_port(PA_9, PA_10, 16, 16); // tx, rx, buffer size, multiple

DigitalOut myled(LED1);

char LobotCheckSum(char buf[])
{
  char i;
  uint16_t temp = 0;
  for (i = 2; i < buf[3] + 2; i++) {
    temp += buf[i];
  }
  temp = ~temp;
  i = (char)temp;
  return i;
}


void LobotSerialoneServoMove(uint8_t id, int16_t position, uint16_t time)
{
  char buf[10];
  if(position < 0)
    position = 0;
  if(position > 1000)
    position = 1000;
  buf[0] = buf[1] = LOBOT_SERVO_FRAME_HEADER;
  buf[2] = 0x08;
  buf[3] = 0x03;
  buf[4] = 0x01;
  buf[5] = GET_LOW_char(time);
  buf[6] = GET_HIGH_char(time);
  buf[7] = id;
  buf[8] = GET_LOW_char(position);
  buf[9] = GET_HIGH_char(position);
  serial_port.write(buf, 10);
}


int main() {
    //serial_port.set_baud(115200);
    //serial_port.set_format(8,BufferedSerial::None,1);
    //char buf[10]={0};
    while(1){
        myled = 1;
        LobotSerialoneServoMove(ID1, 700, 1000);//id, pos, time
        LobotSerialoneServoMove(ID2, 500, 1000);
        wait_ms(1000);
        LobotSerialoneServoMove(ID1, 500, 1000);
        LobotSerialoneServoMove(ID2, 600, 1000);
        wait_ms(1000);
        LobotSerialoneServoMove(ID1, 900, 1000);
        LobotSerialoneServoMove(ID2, 700, 1000);
        wait_ms(1000);
        LobotSerialoneServoMove(ID1, 500, 1000);
        LobotSerialoneServoMove(ID2, 600, 1000);
        wait_ms(1000);
        myled = 0;
        wait_ms(1000);
    }
}