function s_out(n,v)

%v is the value of the voltage
%n is the number of the channel
%v_code=32768+((v*8.8/1.9-2.5)*10^4/2);%計算5622的電壓碼,加運放
v_code=32768+((v-2.5)*10^4/2)%計算5622的電壓碼
s = serial('COM1');
fopen(s)
set(s,'DataBits',8)
s.BaudRate=2400;
fwrite(s,16*(n-1),'uint8')
fwrite(s,v_code,'uint16')
s.BytesAvailable;
v_code_feedback = fread(s,3)
s.BytesAvailable;
%get(s,{'BaudRate','DataBits','Parity','StopBits','Terminator'})
fclose(s)

delete(s)