user82866: I am looking for differences between HC-05 and HC-42 Bluetooth modules for Arduino. I could not find an answer by searching google.
Both products have 6 pins and accept master and slave but I could not find further details on the differences.

user42015: It's different technology. the HC-05 uses the old Bluetooth 2.0 standard. The HC-42 in contrast uses BLE (Bluetooth Low Energy) in version 5.0.
So you have to decide what technology you want to use, either classic Bluetooth 2.0 or Bluetooth Low Energy 5.0.

82866: <p>I am looking for differences between HC-05 and HC-42 Bluetooth modules for Arduino. I could not find an answer by searching google.</p>
<p>Both products have 6 pins and accept master and slave but I could not find further details on the differences.</p>
 42015: <p>It's different technology. the HC-05 uses the old Bluetooth 2.0 standard. The HC-42 in contrast uses BLE (Bluetooth Low Energy) in version 5.0.</p>
<p>So you have to decide what technology you want to use, either classic Bluetooth 2.0 or Bluetooth Low Energy 5.0.</p>
