On 8/31/20 10:01 AM, Anne Ranch wrote:
Bluetooth technology is one of the most poorly documented "stuff" around.
And inconsistently implemented.
The main problem with bluetooth, in MY opinion , there are options, quite a few of them - both software and hardware.
There's also a HUGE difference between "compliance testing" according to the standard and "make it work". Unfortunately the owners of the standard/trademark have never really cracked down on non-compliant devices.
Which one to pick really depends on SPECIFIC application - nothing new about that concept.
On my PC , I am using
Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
as generic bluetooth device with USB interface , roughly $5 item.
Works fine accessing CAT port on FT-857, using chirp software
work fine with NanoVNA-SAVER
On my FT-857 I have "serial to bluetooth " device - work fine, maybe HC5 would work too.
In theory , any USB / bluetooth device should be able to be connected to NanoVNA USB port - via proper adapter.
The tricky part is that the NanoVNA is expecting to see a USB "host", while a lot of BT devices are USB "devices".
Then, there's the whole USB "can be either a host or a device", particularly with USB-C and power transfer.
Of course NanoVNA firmware WITH bluetooth / USB option MAY be on some developer's work list.
Personally - I am curious why developers spent time building bigger, more expensive and less portable displays when adding bluetooth would let user to use ANY size of REMOTE display for few dollars.
( No , I am not interested in writing the software , got my own projects)
Standalone device development (firmware for such devices) is easier to validate. You're not dependent on the (not entirely well documented) behavior of the external device.
I think the ultimate solution will be something like the NanoVNA (which does the measuring) combined with an Arduino, Beagle, or Pi (which does the instrument management and provides a more sophisticated UI).
That way, VNA developers can focus on instrument performance, and provide a set of basic functionality "on the device" having to do with calibration, etc. And the ability to display as a standalone device.
But then, if you had a larger device (tablet, PC, what have you) it could have software that would interact with the NanoVNA.
Conceiveably, for instance, one could write Java code for Android (or whatever is appropriate for iOS) that would talk to the NanoVNA over the existing "emulate a serial port" interface. The tablet/phone/computer is the "USB host".
