BATC Forum

The Portsdown hardware including the RTL-SDR has an enormous potential, and I am keen that this potential is developed as much as possible. I have 2 key drivers: I want the Portsdown to be as useful as possible to me when I am operating from a portable location, and in the shack I want it to aid my construction of other equipment.

To this end, I am looking for a range of "apps" that will be called from Menu 3 of the touchscreen. I know that all of the following are possible, but do not have the time to develop them all and am looking for some assistance:

1. Display an Info screen giving the RPi's IP address, software version, selected modes etc. Edit: Released in 201707311.

2. A range and bearing calculator to enable input of a distant station's locator and calculate the range and bearing using the stored own-station locator.

3. An audio receiver using the RTL-FM package to listen on 144.75 MHz FM or any other selected frequency.

4. An AM TV Receiver (possibly using SDR-Angel) to receive and display AM TV signals.

5. An analog video monitor to display the input from the EasyCap on the touchscreen.

6. A 55 - 4400 MHz signal generator using the ADF4351. Possible extension below 55 MHz using RPI-TX, and to audio using the Pi's audio output. Option to drive the DATV Express board as a Sig Gen with variable output?

7. A sweep generator using the ADF4351.

8. A spectrum monitor using the RTL-SDR. Initially 2 MHz wide, but with possible future development to combine a number of 2 MHz widths to cover a wider range.

9. A Network analyser to align filters using the ADF4351 and the RTL-SDR.

10. RPi TX functionality.

11. Video snapshot. Save a .jpg of the current EasyCap input to the SD Card. I have this working and it will be released soon.

12. Video recording. Record the video from the EasyCap onto the SD Card.

13. Amendment of preset frequencies and Contest numbers from the touchscreen.

As you can see, my imagination has been running wild, but I would like some help from any other coders out there. The developed applications need to run with the current Jessie Lite operating System and ideally should be C code to be "included" in the existing rpidatvtouch.c file. They need to be controlled from the touchscreen and display any output on the touchscreen.

Please PM me if any of these projects take your fancy. I would also welcome other ideas for new applications.

Dave, G8GKQ

Hi.
I'm pretty sure 6,7,8 and 9 would be welcome in very many shacks. I'm also totally blown away by how much has been achieved so far, I can't wait to get my Portsdown on the air.
73 Dave G8TXJ/M5TXJ

Hi Dave,

Great ideas...need to implement (that's all folk

1 - Yes
2 - Great - For mobile station, could add a GPS to incrust location / Locator
3 - Yes - note that rtl_fm could also demodulate SSB (for Dx Stations)
4 Have a proof of concept receiving analog tv with rtl-sdr. No time to go further ..need to publish it for co-working !
4 bis : Analog Tx AM : just need to link analog output of Raspberry to I of modulator (adujusting gain). Using the digital filter already on the board, you could have a Narrowband analog Tx !
5 Easycap is not displayed on the touchscreen right now. But could be added.
6 Yes
7 Could be a separated project
8 GQRX and CubicSDR run on Pi with a slow fft. Work on it with GPU FFT. RTL_POWER could do the trick for more than 2MHZ bandwidth
9 Again an interesting project
10 Love to have a clean rpitx board !
11-12 Could be usefull
13 yes

Hope that others could add other ideas !

Evariste

Dave,

This question arose today. Would the most basic version of picam to QPSK work on a PI Zero?

Mike

What do you mean by basic ? Do you mean this :

pizero + picam + I/Qmodulator at 100mw ?

I probably do - what can it do?

Linux support for the Minituner hardware?

Evariste,
Very impressive, could we please see a picture/circuit of the modulator, is it the old style CIMKO board?
Dave, as far as a spectrum analyzer goes, Jean Pierre said he was looking to implement a spectrum analyzer with Minitioune
That was before Serit tuners came along, I'll ask him
Roger

Jean Pierre said
"I have started to work on it, but it is a long work, there are now so many different NIM that don't have the same specification.
I hope to finish it, but many things to do before that"

Guessing the X Frequency scale is straightforward but the Amplitude Y scale is a function of the different NIMs response
Each NIM would need calibrating to be meaningful, if that's correct
I originally suggested a couple of uses for the second tuner of the Serit, it should be used for something, it seems like a waste otherwise
Even a few uncalibrated bumps would be good, or a blind tuner on the second input maybe
Well he's done a pretty impressive job with it so far, maybe he'll surprise us