Browse over 10,000 Electronics Projects

AD9834 / ESP8266 Beacon

AD9834 / ESP8266 Beacon

Well – the connected ESP 8266 beacon is now running with its new AD9834 heart pumping pure RF sinewaves…

Last week’s report was made in good faith – but I hadn’t realized at time of posting that the DDS was only being controlled to VERY poor frequency resolution. In fact, I could only adjust the frequency in something like 3kHz increments. Obviously, something was very wrong!

I wasted a lot of brain cycles trying to track down the problem and ended up abandoning the AD983X library (which I could not get to work properly with either an Arduino UNO or Mega – much less the ESP8266).

Instead, I took inspiration from Diz Gentzow, w8diz’s work (well reported by Bruce Hall, w8bh) and Akio Mizuno’s Arduino AD9834 DDS and I went back to my old “Soft SPI” approach.

This paid dividends – after doing the initial development work with an Arduino UNO and a logic analyser, both of which you can see in the photo below, which shows the proto-beacon on the bench…

You can also see the amplifier I’m using for the beacon (it is the original prototype of the m0xpd / Kanga Sudden Tx shield) and the filter on the amplifier output.

As well as (correctly) controlling the AD9834, the ESP8266 connects to the internet to get the time from an NTP server, as has been described previously. This allowed the beacon to be heard immediately on its very first ‘shout’, with no intervention whatsoever from me.



Advertisement


Here are the reports from wsprnet.org of that first shout this morning…

and the same in visual format…

As well as transmitting WSPR, the beacon is transmitting other QRSS modes which could be received on “grabbers”, such as that operated by Steen, la5goa in Norway

(my callsign, ‘m0xpd’, seen twice in the red box).

I left the beacon running for a few hours and now there’s a fuller ‘net’ of signal reports for the new beacon – here’s the complete set of (WSPR) Rx reports since turn-on…

The next step is to turn the pile of spaghetti on the bench into something a little more permanent.

…-.- de m0xpd

 


Top