mapping/wireless transmitting/lcd help

i'm having difficulties trying transmit battery voltage measurement data. i've created external voltage divider in order create necessary 5v max analog input. want transmit data arduino board (via xbee) create remote battery monitor. below code have right (not of it, parts pertain problem.
the transmitter code:

code: [select]


int b_volt = 3;
byte batvolt;
void setup() {
 serial.begin(19200);
}

void loop() {
 batvolt = map(analogread(b_volt), 0, 1023, 0, 245);
 serial.print(250, byte);             // ------------------------sync
 serial.print(batvolt, byte);        //battery voltage reading
}


the code receiver:

code: [select]


byte rembatvolt;
void setup() {
 serial.begin(19200);
}

void loop() {
 if (serial.available() > 0) {
   incoming = serial.read();
   if (int(incoming) == 250) {
     rembatvolt = serial.read();
     rembatvolt = map(rembatvolt, 0, 245, 0, 1023);
   }
 }
 lcd.setcursor(0,0);
 lcd.print("remote batt.: ");
 lcd.print((int(rembatvolt) / 83),dec);
 lcd.print(".");
 lcd.print((int(rembatvolt) % 83),dec);
 lcd.print("v");
}


when run code, know value transmitted 169, received value 28. suggestions?

code: [select]

if (serial.available() > 0) {
   incoming = serial.read();
   if (int(incoming) == 250) {
     rembatvolt = serial.read();

you check @ least 1 byte, , read 2 (if first 250).
you need make sure second byte has arrived before trying read it.

quote

when run code, know value transmitted 169

which one? sending 2 values.

quote

but received value 28

which one? receiving 2 values.

code: [select]

 lcd.print((int(rembatvolt) / 83),dec);
 lcd.print(".");
 lcd.print((int(rembatvolt) % 83),dec);
 
83? did come from?

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