Dennis,

>>No such luck I'm afraid.   I'm looking at the HC-05 datasheet here :
>>
>>https://components101.com/sites/default/files/component_datasheet/HC-05%20Dat
asheet.pdf
...
> Unfortunately, that PDF uses images, and not formatted text -- so
> no cut&paste...

I'm sorry, but I ment that I actually looked at the contents of that PDF
(read: it opens fine), and found that the names for the pins on the breakout
board do not match any names in that PDF document (though I went a bit of a
stretch for the RXD and TXD pins - those are rather easy to find the similar
names for :-) ).

> How to set the mode to server (master):
> 1. Connect PIO11 to high level.

I found a webpage describing that process for a button-less module.  I saved
it for a "just in case" case.  And whatdoyouknow, it has become just that.

> which does seem to follow what one document implied for the EN
> pin -- used to enter command mode rather than data mode.

Not quite.  It could as easily be connected to the RESETB pin (pin 11).

> Note that the actual chip has a lot of pins, many used for esoteric
> reasons

Indeed.   Especially the USB pins, and asked myself if I could perhaps wire
it up to an USB connector - only to realise that if the firmware is not
written for it neither the SPI nor the USB pins will do anything.   Heck,
those hardware parts might not even be on the used chip.

>    Although many of these mounted devices are compatible
> with 5 V logic levels, they do work just fine with 3.3 V.

Although I would gladly accept that (would make my life /that/ much easier),
its not what the specs to the HC-05 breakout board says : a 3.6v minimum
voltage.   But, I don't know why they say that*, as the HC-05 module itself
will, according to the PDF, happily work with a supply as low as 1.8 volts
...

*other than perhaps to guarantee that the I/O "high" level is at 3.3v.

>    Some may have a small switch connected to pin 34.

The breakout board has some space for that button, but its not present.
With some luck the track is connected to that pin though, allowing me to put
a makeshift switch there myself.

> The fifth image down on the Amazon page (at least for me) is just the
> schematic at a somewhat larger scale. The diode part is
>
> UART_RXD --->|--- RX_TTL

Could you post the direct link to that image ?

> If using an active ohm/resistance measuring mode, I'd be concerned.
> DVMs tend to run 6-9V (4xAA, 1x9V) through the leads when
> measuring resistance.

Thats something that crossed my mind too ...  Though I got very little
choice if I want to check where the STATE pin connects to.

Thanks for the help - again. :-)

Regards,
Rudy Wieser

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