开云体育

A good friend of mine was fond of putting on the 'Irish' and saying "good t'inkin' O'Rourke - yer foired!" <grin>. That's the sort of t'inkin' (tinkering?) I like - fun indeed! :)

73 de ZL2DEX

Nice to see someone working on multiband.
Wondering if you might share project.?
I have built bandpass filter for 20m and rx is good.
The lpf for 20 is causing an issue. High swr.
Tried several lpf? filters with same results.

Joe
VE1BWV

Yes, a USB dongle on the RPi could listen to Bitx40 audio.
Should work, and requires no new PC boards.
Could use one of the many si5351 breakout boards with the RPi.

But ?I'd tend to build a small PC board for an si5351, ad8307, and i2c ADC. ?
Put duct tape under it to insulate any vias,
then lay it flat on the bottom of the bitx40v3 pc board and solder the corners
to the bitx40 groundplane using short wires. ?Solder wires for power, audio, bfo, vfo.
Only needed connection to the RPi (or most any such processor) is the i2c bus.
Can be used without the Bitx40 as a sweeperino.
Then of course, we need to decide if we also want to drive PTT and mike audio somehow.

The Nano is interesting because everybody who buys the Bitx40v3 has one.
The RPi is interesting because it opens up a lot of new possibilities.

Jerry, KE7ER

The only ADC needed would be for S-meter. Tune by mouse (dragging across beneath waterfall like websdr.com) or scroll-wheel, or keyboard to dialog box. Mono audio, so one channel of a USB dongle could serve - what say?
73 ...

Sweeping? Band is 200kHz (or 300), audio is say 2kHz, so 100 (150) steps, enough time to process an display a waterfall of that audio and stitch it onto the previous ... should be doable :)

For another $5 you can go from the zero to the zero W and have wifi.? Then you can VNC into the pi and skip the HDMI.? I am using a zero W with the HAT from TAPR as a WSPR transmitter and remote op it from my phone or desktop.? The HF was knocking out the pi's wifi.? I separated the HAT from the pi with 20cm jumpers and it runs like a champ.? Might need some shielding between the pi and the bitx board but it might work.? As a bonus you can sync NTP and all the fun that comes with accurate time.

If the code is in C then it remains in common with those using the Nano, and updates to one
can be easily ported to the other. ?Perhaps in C but with hooks so parts of it can be called
from python for RPi specific stuff, like a graphic waterfall display out to an HDMI monitor
of all activity across the band (by sweeping the si5351 VFO and monitoring the audio).

Jerry, KE7ER

Absloutely! though LCD support not necessary - display by the Pi's HDMI.
73...

You are correct about the 3.3V I/O and lack of ADC pins.? I imagine we'd design a special 'HAT' (as Pi daughterboards are often called) that contained an ADC like the one you suggested plus the Si5351 and other miscellaneous circuitry (such as 5V output drivers and LCD support circuitry) and just replace the entire Raduino instead of just the Nano.

As far as coding in C is concerned, I am fine with that.? I use Linux every day at work and have been coding C for over 30 years now.? I just thought Python might be less intimidating for people unfamiliar with Linux and the Raspberry Pi, as it seems to be the language of choice for new Raspberry Pi users.??

Greetings, all!

I seem to have put a cat among some pigeons! :) My hope would be that they can fly ... me, I'm hobbled.

Financially - I'm a pensioner, and my reserves have been pillaged by bureaucracy. Beyond the original Kit and replacement Raduino, such componentry as I can glean is from defunct 'trash', tools are what I had prior to that systemic abuse. I envy those in nations with reasonable access to less-costly 'gear'. Here in NZ, and lacking individual mobility beyond this little town (Feilding, FYI) a Pi Zero-W will cost at least double its price at the nearest outlet (Element 14 in Auckland).

Situationally - workspace is cramped, storage cluttered with inadequate room for organisation.

Capability - my programming capability doesn't go beyond schoolboy BASIC and atrophied Assembly. I'm a Thinker, not a Doer.

I'm active here to keep my brain functioning - I've had a stroke. Online is my preferred human interaction. My long-term memory is unimpaired, so knowledge is not a problem - and more recent developments here are documented and can be researched. I really treasure this project!

73, folks

Dex, ZL2DEX

?

Yes,?the?RPi?does not have an ADC, so you would need to add an external one. There are a number of options available from Adafruit:??(and of course, even more options on eBay, but without the support you get from Lady Ada).?

Doing a little poking around on speech processing and ran into a couple of interesting possibilities, not necessarily cheap.

A very powerful homebrew digital approach:

From a previous hobby, an analog approach:

The IC has a VCA, an RMS detector and a couple of opamps.

See especially Design Note 115:



That design note is based on the chip that uses ±15V for power; the 4320 is the same thing that can run on 12V which is available in the BitX.

Is anyone using pro audio hardware for this sort of thing?

Update: The measurements I took earlier seemed odd. Further experiments (better setup) displayed actual delay for both operations are closer to 735 uSec each. Makes more sense. 73, Don, ND6T

Wouldn't an RPi need an external ADC?

Hmmmm, I wonder if there would be enough processor to run some sort of digital audio workstation app with compressor/gate/limiter/eq plugins for TX audio processing.

Should work.
The RPi-Zero is $5, and way way way more capable than a Nano.
Note that the RPi has 3.3v IO pins, not 5v like the Nano.

Could get by without any analog pins, or could add something like this:
? ??Cost is somewhere between $1 and $3 for just the chip, depending on how many you buy.
Probably need to cook up an OSHPark board for that plus an si5351, maybe an ad8307 too.

I'd leave Allard's code in C, the RPi can run linux, and has the gcc compiler.
Just need to move from Arduino's wire.h library to code suitable for the RPi's IO ports
and clean up the minor Arduino-isms, like add a standard C main() at the top level:
? ? void main() {?setup();? ? while (1)?loop(); }?

But if you really want to re-code Allards sketch in python, go for it.
That's what this is all about, learning and having fun and staying out of the bars.
No need to rationalize beyond that.

Jerry, KE7ER

A quick bench test revealed an ON time delay of 800uSec using set_freq() and a 480uSec delay in turning it off with output_enable(). This was with the Etherkit version 2.0.6. I pulsed a digital pin before and after each activation of the '5351 to duplicate your test and measured with a 100 MHz DSO
I use that method at speeds up to 35 WPM without noting any difference. However others may disagree. This is not the "normal" way of turning it on, just a shortcut that works faster than the output_enable() method for me. 73, Don,ND6T

Hey guys,?

I’m finishing up my build of a multi band BitX and need two more bands to fill my filter board. I already have 80, 40, & 20 meters in place. Has anyone gone higher than 17 meters without an I.F. amp? (like the Hycas or similar)

I joined this group a few weeks ago, and have been lurking about trying to learn as much as I could about the Bitx/uBitx before making the plunge.

I, too, have been considering replacing the Arduino with a Raspberry Pi to get better horsepower, memory, and more GPIO for added featues.? I also think a Pi would be a good choice for adding support for digital modes as well support for CW encoding / decoding via a USB sound card.? The other nice thing is that the recent versions of the Pi (A+, B+, 3, Zero, Zero-W) all share a common 40-pin GPIO interface, so each user could choose the Pi that works best for them without impacting compatibility.

I'd be interested in collaborating on using a Pi instead of an Arduino for the Bitx/uBitx.? Should be fairly easy to convert Allard's Arduino sketch to Python to run on the Pi.??

73

Carl, K0MWC