If you are using a wired Serial connection have a look at the examples in Serial Input Basics - simple reliable ways to receive data.
The technique in the 3rd example will be the most reliable.
You can send data in a compatible format with code like this
Serial.print('<'); // start marker
Serial.print(value1);
Serial.print(','); // comma separator
Serial.print(value2);
Serial.println('>'); // end marker
If you would prefer a wireless solution then a pair of nRF24L01+ modules would be cheap and effective. Have a look at this Simple nRF24L01+ Tutorial
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