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F5OEO / rpitx

RF transmitter for Raspberry Pi
GNU General Public License v3.0
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Does not seem to Tx #6

Closed haxorthematrix closed 5 years ago

haxorthematrix commented 8 years ago

Raspberry pi B+ with wire attached to appropriate gpio pin. Receiving with RTL-SDR and HDSDR under windows, tuned to 107Mhz (an unused FM station, low, low power FM Tx is legal in the US).

I cannot observe any Tx from the pi with the RTL-SDR, using either:

sox imperial_march.wav imp.wav rate 48000 channels 1 pifm imp.wav imp.ft sudo rpitx -m RF -i imp.ft -f 107000

or

convert -depth 8 Picture.jpg picture.rgb ./pisstv picture.rgb picture.ft sudo ./rpitx -m RF -i picture.ft -f 107000

Both commands return, almost immediately (less than 1 second delay) with:

rpitx Version 0.1 compiled Dec 9 2015 (F5OEO Evariste) running on Model Pi B+ Model Pi 1 END OF PiTx

I have attempted with and without the patch from Issue #1. The pifm project, on the same pi works perfectly with the antenna attached to a different GPIO pin, as required by the pifm project.

F5OEO commented 8 years ago

Try latest version...it detects if you are running Wheezy or Jessie which seem to be the problem (DMA channel)

haxorthematrix commented 8 years ago

SSTV appeared to transmit, but was only able to verify with the HackRF One and Portapack waterfall display. I will investigate further.

redfast00 commented 8 years ago

Same here: pifm works great, but rpitx doesn't seem to transmit (tested with rtl-sdr dongle)

F5OEO commented 8 years ago

When there is an issue : please report console output and details of issue. Just saying doesn't work is not helpfull to fix it !

haxorthematrix commented 8 years ago

Ok, more investigation. With the latest pull, transmission appears to be better, specifically with SSTV:

sudo ./rpitx -m RF -i picture.ft -f 103000 rpitx Version 0.1 compiled Dec 16 2015 (F5OEO Evariste) running on Master PLL = 1000000000 Model Pi B+ Model Pi 1 Jessie MASH 1 SampleRate=100000 WaitNano=25000 F1=205994769.664052 TuneFrequency 206000000.000000 F2=206005130.0 10562 Initial Resolution(Hz)=10360.346510 ResolutionPWMF 65.159412 NbStep=159 DE LAYStep=14 \ STARTING TRANSMIT **** END OF PiTx

Tx takes about 4-5 seconds. I can verify that signal is recieved by an RTL-SDR, as the SDR# waterfall display changes, but fails to decode with MMSSTV (the decode may be my problem however, I am still experimenting)

redfast00 commented 8 years ago

It says it's transmitting, but I don't see anything in gqrx. When I use pifm (from pifm project), I do see and hear an fm-signal.

redfast00 commented 8 years ago

Is this related to the difference in pin used? (pin 12 vs pin 7)?

ha7dcd commented 8 years ago

Of course! Its a completely different signal source, you need to use the propet gpio for rpitx and for pifm as they use different pins On Dec 17, 2015 10:27 PM, "redfast00" notifications@github.com wrote:

Is this related to the difference in pin used? (pin 12 vs pin 7)?

— Reply to this email directly or view it on GitHub https://github.com/F5OEO/rpitx/issues/6#issuecomment-165585962.

redfast00 commented 8 years ago

When using pifm, I don't attach an antenna and still receive it fine

F5OEO commented 8 years ago

Can you give what the output of your command and the result rpitx give ...

2015-12-19 13:55 GMT+01:00 redfast00 notifications@github.com:

When using pifm, I don't attach an antenna and still receive it fine

— Reply to this email directly or view it on GitHub https://github.com/F5OEO/rpitx/issues/6#issuecomment-165982463.

haxorthematrix commented 8 years ago

Ok, coming back around to this one. I don't know what happened, but I have it working. Changed SSTV decoder to QSSTV and it worked great. I did so many things in the mean time, including a git pull recently that who knows. It works now!

OutsourcedGuru commented 7 years ago

Like @redfast00 suggested, within several feet of your project the standard Raspi pins are long enough to transmit without any antenna whatsoever.

I've been known to put my oscilloscope probe into one end of my antenna and then "walk" the far end of that antenna wire from pin to pin until it shows me the correct output pin (12, in my case).