I have just published a software update for the Portsdown 4. It includes 2 changes to the GPIO pin allocations to move services off of 2 pins that are reserved on the Raspberry Pi 4.
- The first is that the band LSB connection moves from pin 28 to pin 32
- The second is that the pin allocated for ADF4351 LE (unused on the Portsdown 4 until now) moves from pin 27 to pin 33.
Colin has already published details of coordinated changes for the Langstone band switching.
The full list of changes and new features is:
- Modify Band LSB and ADF4351 LE GPIOs
- Add Initial ADF4351 Sig Gen Capability
- Blink display on successful snap
- Reduce dhcp timout for new builds
- Use Raspios Buster Lite 2020-08-20 for new builds
So, with the addition of an ADF4351 (as used with the Portsdown Filter-Modulator board) your Portsdown can serve as a Signal Generator from 35 MHz to 4.4 GHz; connections (pins 29, 31 and 33) are published here
https://wiki.batc.org.uk/Portsdown_4_GPIO_Connections. Future updates will extend the library of output devices and hence the frequency range. You can select the signal generator from Menu 2.
Other changes blink the display to indicate successful screen capture and, for new builds only, reduce the boot time with no network connection and use the latest Raspios software.
Dave, G8GKQ