RX frequency change during TX: Bug or feature?

[oe5rho]

Hello all and thanks for reading.

I put the latest (0.2.4) tezuka image on my fishball sdr board and it made my day! Now the usb serial adapter is recognized stable and I can continue my project. (Trying to build a general purpose VHF/UHF/SHF transceiver that can be controlled via LAN)

I use SDRConsole on the PC side and a shell script on the fishball board that uses iio to sends tx lo status, tx frequency and rx frequency to /dev/ttyUSB0. An Arduino Nano receives it and takes care of amplifier and antenna selection and tx ptt sequencing.

What I have noticed now: In full duplex rx and tx frequencies don't change when I switch to transmit as expected. If I use half duplex when I switch to tx the rx frequency does not change on the SDRConsole but iio reports a rx frequency equal to the tx frequency. It is changed back after switch back to rx. This was not the case with the original firmware.

Question now: Is this intended and if yes why? If not can it be changed?

Regards, Roland

p.s.: If you have have been trying to get the fishball USB port working in host mode and had no luck read on. I first tried to connect a FT232 adapter to the usb port with a standard OTG cable but could not get it recognized. It took me a while to figure out that they have connected the ID pin from the usb controller chip to pin 8 instead of pin 5. I ended up modifying an otg adapter and connecting pin 8 to ground and now my Arduino is detected an /dev/ttyUSB0 created.

[F5OEO]

Hi Roland,

Happy that your project is moving forward. I need to investigate mode in TDD, as I always use FDD (Full dpulex).
Note that if you have a fishball with GPIO (opensourcelab) , you can use serial on the GPIO (next version of firmware) , no need of usb anymore.
I need to inspect pin8 and pin5 !

Let continue to feedback !

[oe5rho]

Thanks for the instant reply!
Unfortunately I have the hamgeek fishball board which has no GPIO at all. I bought it as I was misled by the rx and tx lo connectors. Thought I could sense tx lo to get ptt switching independent of firmware just to discover they are inputs...
But having a second usb-c port for the console is also nice and thanks to your great work I have a firmware that gives me all I need on the usb port.
I have also discovered the mqtt server and your Arduino solution but I'm not so familiar with mqtt so I stuck with the shell script as its very low on resources an fast and I can keep the Arduino busy with keeping track of the position of all the coax relays an amplifier power switches.

73 de Roland

[F5OEO]

" It took me a while to figure out that they have connected the ID pin from the usb controller chip to pin 8 instead of pin 5"
Can you point it on schematics ?
fishball7020.pdf