Great that you found the problem! Without the proper wiring nothing would work.
It also means everything regarding the power button is done in user space and that there is probably another service installed, besides the one you got from the Saturn repo, that starts the script you showed.
That script ...

Indeed nothing there that would support power-on LED or Shutdown.
The LED having been taken care of, this leaves the gpio to be set that, when pulled low, should trigger OS shutdown.
The two gpios that you earlier reported are the result of the script you ran to get the power-on LED, and the other ...

what is in /boot/config.txt concerning this?

Had a look at the fix-LED-power-button.sh script and it seems to only address indeed the LED action, not the shutdown.
The original front-less G2 has defined in config.txt:
>>
dtoverlay=gpio-shutdown,gpio_pin=26
gpio=15=op,dh
<<
The script replaces the effect of the second line by a systemd service ...

Agree with Laurence that from the video it would appear that the serial communication between the Arduino and the 50 pin CM4/5 connector is working.
The Arduino, instead of sending one or a few ZZZU/D messages to the CM4/5 serial interface when the knob is turned, to be processed by Pihpsdr' rigctl ...

I mentioned the FPGA not because of performance but because its programming needs to be done and supported somewhere and has details that are very specific to the exact rest of the SDR hardware.
It apparently not being 100% identical to a SDR we already know, it makes me wonder who made the gateware ...

@wu2o
thanks for elaborating on the various aspects of the G1, like community support and where to discuss in the forum, the G1.

Had not expected your association of this G1 with the Anan 8000 (DLE I presume).
When I look up the specs I see for the 8000 two AD converters and diversity reception. So ...

'support' being mentioned, who will support the software side of G1 things? Was it a group of hams that designed it and made the FPGA code open source and is that accessible somewhere?
Or is the G1 a proprietary thing, to be fully supported by A-L?
Reading the announcement it states that the G1 is ...

Am streaming received audio here from a G2 with Radxa CM5 where Pihpsdr runs, to internet.
The trick is indeed to define Pulseaudio virtual sinks, two of them when you want two-way comms. These Pulseaudio sinks automatically create monitor sources that can be used to pick up the audio signals.
Just ...

Not in a literal sense of your question, using all three.
But am using the 3.5 mm Mic input with the G2 in stand-alone operation, using Pihpsdr running on it.
In the Pihpsdr menu to setup the radio you can make adjustments for the ring/tip function of the microphone plug, and y/n bias voltage to be ...

@John, N2KBE
The System on Chip BCM2712 (Rpi CM5) has a lower specification than the RK3588S2 (Radxa CM5) due to latter being octo core and being manufactured in 8 nm technology, opposed to 4 core and 16 nm. The smaller design rule allows for better price/performance and for increased clock ...

@wu2o
quite right, subtraction in case of diversity reception is an over simplification; the I and Q are combined while allowing amplitude and phase adjustment. Further processing in WDSP is then done for the one resulting IQ pair. With two receivers active independently, both IQ pairs are processed ...

Screenshot via VNC of my G2 with Radxa CM5, running two receivers at 1.5 Msamples/s each, one tuned on 20 m. and the other on 15 m. band.
Screenshot_G2_w_Radxa_CM5_ws.png
Total load average of all processes running, including the vnc server, is at around 2.5 out of 8 (source: 'htop'). I modified ...

@N1GP
sure, I'll inform you where to download.

@N1GP
two reasons for cutting back and gluing the heat sink:
1. while the position of the heat sink screws is exactly right, the metric screw size is much smaller than that of the nylon screws that the Saturn board applies.
The tiny screws that come with the heat sink don't have the length to reach ...

@WD5GWY
The front panel with LCD and knobs is just another control input, and video output, as seen from Pihpsdr running on the (Rpi) CM4 or (Radxa) CM5.
It is sufficient to compile Pihpsdr with the GPIO option active in its Makefile and it will 'see' the front panel.
The bulk of CPU work is related ...

For those that like to experiment with embedded software and Compute Modules I'd like to report some recent results with an upgrade inside the G2.
Replaced the Raspberry CM4 module by a Radxa CM5 in a G2 w.o. control front. The CM5 features a Rockchip rk3588s2 System-on-Chip in 8 nm technology ...

suggestions for G2 changes:
Mechanical:
The micro-usb and full PCIe connectors on the east side of the Saturn board cannot be used because the 3.5 mm IO and microphone/power PCBs are in the way.
Particularly the micro-USB being blocked is annoying since it can be used to make that USB connector ...

Just to document the situation. Some imperfections in CW behavior have been corrected in pihpsdr. The issues I encountered have been cured.

yes, by request from Apache-Labs and for owners of a G2

rig: G2 100W, w.o. ctrl front, embedded pihpsdr, V10 gateware.

To have sufficient directness in CW it is necessary to use the 'CW handled in Radio' mode 'CWHIR'. The keying and cw signal generation are done in hardware, i.s.o. in wdsp. My key is connected to the key input at the G2 rear panel.
I ...

update after trying kernel 6.1 production image:
The mic input works correctly. But the audio chopping at random moments is clearly present at sample speeds where the 6.5.5 stays smooth.
Also noticed that in the 6.1 image hpsdr and p2app can coexist without causing the tx-rx runaway.

Have now also ...

@n1gp
currently writing the sdcard. will report back.
My OS: Linux rpi4b 6.5.5-edge-bcm2711 #3 SMP PREEMPT Thu Sep 28 13:46:42 UTC 2023 aarch64 aarch64 aarch64 GNU/Linux
(uname -a)

@n1gp
Tnx for hints. no luck with setting mic in. Just total silence during tx. E.g. two-tone tx works fine. Also removed .props, to no avail.
Just a thought: Could it be that my experimental OS being 64 bit (arm64) causes some settings to be wrong because intended in the pihpsdr code for 32 bit ...

@Trucker: See
https://datasheets.raspberrypi.com/cm4i ... asheet.pdf
That is a motherboard for experimenting with a CM4. Its just two miniature connectors, very similar to the system used by eMMC memory modules. Just more pins.

@trucker

regarding no mic input when running embedded pihpsdr:
The settings are exactly the same as for the external pihpsdr that I can run on my PC perfectly. Audio on tip, bias active, local audio unchecked as there is none coming from pulseaudio. My guess is that the Saturn codec does not get initialized ...

as the difference between 20 m and the other bands is rather extreme, have you considered checking the filters that are in the transmit path? As a dummy load is used that would not discriminate between bands, nor does the firmware. But a faulty filter could, or a filter switch not happening and the ...

@laurence:
tnx for background info!
Using the Armbian environment made an image on basis of arm64 architecture and kernel 6.5, but with just enough in the OS to let pihpsdr show its GUI. So basically just cli plus X11 and Openbox Have patched 'your' xdma driver into it and for now called it xdma2 as ...

@Laurence; encountered the xdma code in kernel 6.5. The xdma.c code starts with this intro:
/*
* The DMA/Bridge Subsystem for PCI Express allows for the movement of data
* between Host memory and the DMA subsystem. It does this by operating on
* 'descriptors' that contain information about the ...