Radioberry firmware and gateware source code questions

[qrp73]

Hi, I'm trying to find the code which processes HPSDR protocol packets, especially I'm interesting on how gain setting is processed.

The gain setting in HPSDR protocol is passed as a byte 4 in control bytes at page 10.

This byte has 6 lower bits (bits 0-5, mask 0x3F) for gain value and bit 6 to enable or disable gain.

But I cannot find the code which process this byte. Could you please point me, which file in the source code has the code to process it?

Best regards

Alex

[pa3gsb]

Hi Alex,

As you may have seen since the introduction of the RPI-4 i decided to use the nice variant fpga code structure of the hl-2.

For the radioberry some specialities are added.

https://github.com/softerhardware/Hermes-Lite2/blob/master/gateware/rtl/radioberry/ad9866ctrl.v

and there you will find your answer:

  // Linear mapping from 0to255 to 0to39, like Hermes-Lite 1
  tx_gain_computed = ((cmd_data[31:24]+4) >> 3) + (cmd_data[31:24] >> 5);

To make the tx gain more lineair you need to change the following lines:

Just 2 lines to change in the gateware code.

ad9866ctrl.v:

  initarray[16] = {1'b0,8'h84}; // Address 0x10, Select TX gain
  initarray[17] = {1'b0,8'h00}; // Address 0x11, Select TX gain

Some weeks ago i found the reason why the tx gain is not lineair.  I did not have the time do the fix and making a new release.

The gain distrubution when using the driver looks now something about (thanks to yado-san for the diagram)

Enjoy the radio

73 Johan

PA3GSB

Op dinsdag 5 maart 2024 om 18:47:29 UTC+1 schreef qrp73:

[Wim PE1PWR]

Hi Alex.

Contact Johan the maker of the project for it.

He must now what you are looking for.

pa3...@gmail.com is his email address.

Hopes this helps you.

KR

Wim

BlueMail voor Android downloaden

Op 5 mrt. 2024, om 18:47, qrp73 <qrp...@gmail.com> schreef:

[qrp73]

Hm, now I'm confused.

I'm looking at source code in this repository: https://github.com/pa3gsb/Radioberry-2.x

According to installation script it uses already compiled gateware from this path: https://github.com/pa3gsb/Radioberry-2.x/tree/master/SBC/rpi-4/releases/dev/CL025

Where I can find the source code of this gateware?

Do you compile it from this source? https://github.com/softerhardware/Hermes-Lite2/tree/master/gateware/rtl

Where is the rpi4 code which receive UDP packet from SDR app, process it and sends to gateware?

I found this code: https://github.com/pa3gsb/Radioberry-2.x/blob/10348ea7906646f97ab978ee9e2d9221318a3853/SBC/rpi-4/device_driver/firmware/radioberry.c#L346

But I'm not sure what is going on here. What happens at these two lines: https://github.com/pa3gsb/Radioberry-2.x/blob/10348ea7906646f97ab978ee9e2d9221318a3853/SBC/rpi-4/device_driver/firmware/radioberry.c#L336C3-L337C22

```

        push(command);
sem_post(&spi_msg);

```

does it means that linux firmware sends HPSDR packet as is to the gateware and it is processed on gateware side?

[qrp73]

Also could you please explain what happens in this line: https://github.com/softerhardware/Hermes-Lite2/blob/164b11627db40472148e51a2366c7ed384c0f690/gateware/rtl/radioberry/ad9866ctrl.v#L183

```

icmd_data[5:0]  = rx_gain[6] ? rx_gain[5:0] : (rx_gain[5] ? ~rx_gain[5:0] : {1'b1,rx_gain[4:0]});

```

It seems that bit 6 is used to select gain encoding type? I thought this bit is used to disable/enable attenuator.

Best regards,

Alex

[pa3gsb]

Hi,

The code from HL-2 is compiled and the result radioberry.rbf is indeed copied into release folder of radioberry.

You pointed to the right firmware ; there the  udp (or even tcpip connection for running with pihpsdr) is received and transferred to the gateware using the radioberry driver; the driver does communicate via SPI with the gateware. Your code points to the place where the command from the ethernet packet (from SDR program) is placed in a queue which is indeed transferred to the gateware via ioctl to the driver.

 For overview: https://github.com/pa3gsb/Radioberry-2.x/wiki/Radioberry-Software-stack

How the rx gain is handled is described here : https://github.com/softerhardware/Hermes-Lite2/wiki/Protocol

The rxPGA is having a gain of -12dB to 48dB which is controlled via the rx_gain bits.

Hope this helps.

73 Johan

PA3GSB

Op dinsdag 5 maart 2024 om 21:14:08 UTC+1 schreef qrp73:

[qrp73]

Thanks, now it's clear. Previously I thought that it uses custom protocol between firmware and gateware and processes packets in software on rpi side. But now I see that it passes HPSDR packets to gateware and it is processed on gateware side.

Best regards,

Alex