Portsdown 2020 Getting Started Guide
The Portsdown 2020 build is primarily intended to be used with the LimeSDR Mini loaded with the custom LimeDVB Firmware. If you do not intend to use this new firmware it is not, at this stage (Feb 2020), worth switching to the Portsdown 2020 build - the more mature 2019 build could be better.
Background
The Raspberry Pi 3 has to work quite hard to drive a LimeSDR to transmit DVB-S and DVB-S2. In response to this, custom firmware has been developed for the LimeSDR Mini (only) that enables it to take on some of the processing load of generating QPSK and 8PSK modulation.
This "LimeDVB" firmware must be loaded over an existing firmware load, and must be driven with different software on the Portsdown. Because it works differently, the power output is lower than the conventional software, but a cleaner signal is generated. Initial tests indicate that the normal receive capabilities of the LimeSDR are retained with the LimeDVB firmware loaded.
Setting up to use LimeDVB
- First of all, you need to set up the Portsdown to generate the signals to drive the LimeSDR Mini with the custom Lime DVB firmware. Connect your LimeSDR Mini to your Portsdown Raspberry Pi (preferably through a powered USB hub) and power on. Select LimeDVB as the output mode for the Portsdown: On Menu 1 (the main Menu) on the touchscreen, select "Output to" and then select "Lime DVB" (which should not be greyed out). Confirm that Lime DVB is shown on the "Output to" button on Menu 1.
- Next check the firmware on the LimeSDR Mini. Select Menu 3 (M3), then "Lime Config". Then select "Lime FW Info". Towards the bottom of the displayed list, you will see Gateware version 1, and Gateware revision 26, 27, 28 ,29 or 30.
- If the revision number is not 30 (so not Firmware 1.30) you need to update your LimeSDR Mini firmware to 1.30. Select "Update to FW 1.30". You should see a message "Upgrading Lime Firmware to 1.30" and then after 20 seconds or so "Firmware Upgrade Successful. Now at Gateware 1.30 Touch Screen to Continue".
- If your firmware was at 1.30, or you have successfully upgraded, you then need to load the custom LimeDVB firmware.
b. Upgrade to gateware revision 30. Option 7 Lime Config, Option 5 update to FW 1.30. Press enter. Then y, enter, watch progress and then press any key.
c. Next, IN ALL CASES, you must overwrite some of the Lime gateware for the LimeDVB software. Option 7 Lime Config, Option 6 Update to DVB FW. Press enter. Then y, enter, watch