user29415: At most how many bluetooth modules(HC-05) can be interfaced to Arduino UNO?

user4143: Two. One on the hardware UART (TX/RX pins with the Serial object). One on SoftwareSerial on any two pins you choose.
Any more than that and you will need more hardware UARTs. 

29415: <p>At most how many bluetooth modules(HC-05) can be interfaced to Arduino UNO?<br></p>
 4143: <p>Two. One on the hardware UART (TX/RX pins with the <code>Serial</code> object). One on <code>SoftwareSerial</code> on any two pins you choose.</p>

<p>Any more than that and you will need more hardware UARTs. </p>
