HC-05 - does it need voltage divider?

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1

Hi. I have seen a lot of variation in pinouts for this module.

Some require voltage dividers because of the difference between Arduino 5V and the HC-05.
For example:
Voltage divider: calculator and application – Renzo Mischianti
or

HC-05 RF Wireless Bluetooth Transceiver Module RS232 TTL to UART Converter and Adapter (elecbee.com)

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I am not sure if this varies by voltage divider manufacturer.

However, the Core Electronics user guide shows the same as I have seen in some videos: No voltage divider, HC-05 RX/TX go straight to RX/TX on arduino, and VCC goes straight to 5V on Arduino.
My HC-05 lists requirements of 3.3V to RX and TX and 3.6 - 6V for VCC/GND.

I am concerned I might destroy my Arduino board and/or the HC-05.

I did order a core electronics CE07510, a bi-directional logic level converter. Is this useful?

I’d be grateful for any help resolving this.

2

Hey James,
Welcome to the forums!

The HC-05 that we carry on our website has an inbuilt voltage regulator included but does still require a logic level shifter for the RX/TX pins as they work predominantly on the 3.3V Logic level.

If your module is similar (Or the exact same) it should be fine to use the Bidirectional logic level shifter you have purchased from us for the RX/TX pins between your Arduino and the HC-05 module.

Cheers,
Blayden

3

Thanks.
How is the logic level shifter wired?
Your website has this
https://core-electronics.com.au/guides/how-to-use-logic-level-shifters-converters/

Would it be similar to the first example, except the pins go straight to the relevant HC-05 pins?

Thanks,
James