Master / Slave Bluetooth Module (HC-05)

[andrew]

Ah, I guessed PDP-11 because I know they were still used in the 90’s. A lot of interesting old computers you’ve used there.

The range seems very low, but that may be due to all the metal in my workshop. Presumably it's very line-of-sight. Given I have that, what kind of range should I be seeing?

It’s a Bluetooth 2.0 device so in open air, somewhere between 10 to 30 meters but inside a ‘normal’ building it wouldn’t be unreasonable to get 10 meters out of it. I have managed that myself.

If you’ve used other Bluetooth PAN type devices such as headsets you should expect the same sort of range.

Also I assume AT commands cannot be embedded in normal comms data - the AT mode has to be entered and exited so that the appropriate baud rate is selected.

Only while in AT/Command mode I’m afraid and it needs to physically be put into that mode.

There also appears to be, in BT 2.0, a sleep mode, which would be useful if it reduced the longterm ~10mA consumption. Is the sleep/wake protocol handled internally by the HC-05, or does it require the user to generate the required messages and responses?

I’m not aware of any low power modes built into the HC-05 (and with the current version of firmware). It will generally just consume around 10 to 13mA when idle.