BATC Forum

Three questions:-
1) I see on the latest version (2021111120) of Portsdown firmware there is an option for HDMI as a source - I assume this is one of the two micro HDMI sockets on the Raspberry 3? If so which one as I cannot seem to make it work either on aire or with HDMI monitor.

2) I see pin 12 of the GPIO connector is the PTT line as this is around 0v I presume 3v3 or 5v will make Portsdown transmit provided the option in the autostart setup Keyed TX boot or Keyed Touch tx boot.

3) again on hte GPIO Pin 15 is maked power switch I presume this is again either a up to 3v3 or 5v or down to ground to force Portsdown to shutdown nicely. I ask as this unit will become GB3NQ and we already use a orderly shutdown for the Ryde and I want to include the Portsdown in the shutdown group.

Thanks Paul G6MNJ

Hi Paul

1. HDMI source only works with the Pluto (or a Lime connected to the Jetson Nano controlled by Portsdown), and needs an LKV373A set up as specified here https://wiki.batc.org.uk/Jetson_Nano#Pr ... DMI_Device to take the HDMI and encode it as H264. The LKV373A is a great device for taking HDMI and producing an H264 UDP broadcast (I also use it to stream the Thursday net from my Ryde). Unfortunately, other HDMI capture devices need more processing power than is available on the humble RPi.

2. Pin 12 is the trigger for Keyed TX (or Keyed Streaming). Raise it to 3v3 to start the transmission and back to 0v to stop. This was intended for use with the Portsdown 2020 and has not been tested (to my knowledge) on the Portsdown 4. Let me know of it does not work on the Portsdown 4 and I will sort it out. It is described on the Wiki here: https://wiki.batc.org.uk/Hardware-only_ ... _Switching

3. The hardware commanded shutdown needs Pin 15 to be raised to 3v3 to initiate the process. The function must be enabled in the "Shutdown" page of the ssh console menu first.

I would be the first to admit that we need a technical writer to neatly index and document this information. I try to make the touchscreen stuff self-explanatory, but it is more difficult for these less common configuration issues.

Dave, G8GKQ