There is a very clear Interconnect drawing in the Portsdown 2018 area:-
https://wiki.batc.org.uk/File:Portsdown ... nnects.JPG
I cannot locate the new Portsdown 2019 interconnect diagram.
Does it exist?
The reason I was looking for this is that the system diagram of the Portsdown 2019 shows RPI GPIO outputs selecting the bands on the band decoderto illuminate the LEDSand from that board to provide correct RF port switching.
It also shows a connection from the Lime SDR to this board.
My understanding was that the RPI GPIO OR the Lime SDR FPGA pins could be used to control the band switching.
Additionally the wikki suggests NOT using the lime SDR pins for band control.
The diagram also shows a wire labeled PTT from the GPIO but this is labeled TX on my GPIO output board and my Four port Indicator.
This may perhaps give confusion to some builders.
Portsdown 2019 Interconnects
Re: Portsdown 2019 Interconnects
Although I bought a header for the Lime Mini I did not fit it as I decided not to risk the most expensive part of the build.
You can use the connections on the GPIO board for all switching.
The connection labeled TX LED on J05 should be connected to PTT on J1 of the 8 Band Decode board.
The attached photo shows what connections will be required on the GPIO board if you are using the 8 Way Band Decode board and the RF Attenuator board. All connections on J05 are used - they don't show up very good in the photo.
Regards,
Nick - G4NKV
.
You can use the connections on the GPIO board for all switching.
The connection labeled TX LED on J05 should be connected to PTT on J1 of the 8 Band Decode board.
The attached photo shows what connections will be required on the GPIO board if you are using the 8 Way Band Decode board and the RF Attenuator board. All connections on J05 are used - they don't show up very good in the photo.
Regards,
Nick - G4NKV
.
- GPIO Board Connections.
- GPIO Board Connections..jpg (1.58 MiB) Viewed 2692 times
Re: Portsdown 2019 Interconnects
Thanks Nick
I am keeping it simple and jusing the 4 band decoder.
Sounds like the labeling got changed.
I have actually soldered on a header on to my Lime having studied the wiring layout, and seeing this done in pictures on the forum.
Having then read the text the layout drawing did not make sense.
Is the shutdown button still required as the portsdown can be shutdown from the touch screen?
73
Nick
I am keeping it simple and jusing the 4 band decoder.
Sounds like the labeling got changed.
I have actually soldered on a header on to my Lime having studied the wiring layout, and seeing this done in pictures on the forum.
Having then read the text the layout drawing did not make sense.
Is the shutdown button still required as the portsdown can be shutdown from the touch screen?
73
Nick
Re: Portsdown 2019 Interconnects
Also the optional attenuator just takes in 3 lines from the GPIO board.
There is no supply to this on the interconnect drawing.
Referring to the text this should have 5 V as well as the data lines.
73
Nick
There is no supply to this on the interconnect drawing.
Referring to the text this should have 5 V as well as the data lines.
73
Nick
Re: Portsdown 2019 Interconnects
Hi All
As there are many possible configurations for Portsdown 2019, so we have not drawn a detailed interconnect and power supply wiring diagram.
My recommendation is that you use the TX and Band switching lines from the Raspberry Pi GPIO (using the BATC board) to drive the 8-way (or 4-way) switch. This is because it is not easy to connect wires to the LimeSDR Mini and a lot more expensive if you accidentally apply voltages to the lines (which will blow up the FPGA on the Lime) or slip with the soldering iron (£170 vs £40).
I apologise for mixing up my terminology, I have occasionally referred to the TX line (which goes to 3.3v when the TX PA should be switched on) as the PTT or TX LED line. Inside the Portsdown system, the 2 are the same. Once you are beyond the opto-isolator and out into your shack, they have different definitions.
Dave, G8GKQ
As there are many possible configurations for Portsdown 2019, so we have not drawn a detailed interconnect and power supply wiring diagram.
My recommendation is that you use the TX and Band switching lines from the Raspberry Pi GPIO (using the BATC board) to drive the 8-way (or 4-way) switch. This is because it is not easy to connect wires to the LimeSDR Mini and a lot more expensive if you accidentally apply voltages to the lines (which will blow up the FPGA on the Lime) or slip with the soldering iron (£170 vs £40).
I apologise for mixing up my terminology, I have occasionally referred to the TX line (which goes to 3.3v when the TX PA should be switched on) as the PTT or TX LED line. Inside the Portsdown system, the 2 are the same. Once you are beyond the opto-isolator and out into your shack, they have different definitions.
Dave, G8GKQ
Re: Portsdown 2019 Interconnects
No worries Dave
I have just spent the past two weeks drawing out systems diagrams at work trying to get everything in.
Its at rev 4 now !!.
Too late hi hi. already soldered the header but I will just use the Pi GPIO pins.
Looking forward to getting it on the air
73
Nick
I have just spent the past two weeks drawing out systems diagrams at work trying to get everything in.
Its at rev 4 now !!.
Too late hi hi. already soldered the header but I will just use the Pi GPIO pins.
Looking forward to getting it on the air
73
Nick
- lime.jpg (715.42 KiB) Viewed 2647 times