[hpsdr] AngeliaLite project

[Oleg Skydan]

Hi, All!

Some time ago I designed an SDR module for my other projects and 
experiments. The module has two RX channels (with DVGA and 14bits AD9255 
synchronized ADCs) and one TX output (with 14bits AD9744 DAC). There are 
also Cyclone 4 FPGA EP4CE22E22, configuration memory and all necessary 
components for clocking and power it up. The ADCs are clocked at 77.76MHz 
and the DAC is clocked at 155.52MHz by the low noise ABLJO-155.52MHz VCXO 
which is locked from the 10MHz internal TCXO or external reference.

My friend asked if it can be turned into the OpenHPSDR compatible 
transceiver. So, I made it :-). It is two board construction which supports 
OpenHPSDR protocol v2 (but with 100Mb/s Ethernet). It is not a complete 
transceiver - it lacks RX/TX filters and TX power amplifier.

The FPGA firmware is based on the OpenHPSDR Angelia code, the NCO code is 
from the HermesLite2 project. There were many changes in the code to fit 4 
DDCs/2 ADC support into the relatively small and low pin count EP4CE22E22 
FPGA, some changes were required because of the different ADC/DAC sample 
rates, some modules are completely new.

The second board contains Ethernet PHY, standard ALEX, OC, keyer and PTT 
interfaces, four analog inputs, diagnostic LEDs, switching 5V regulator (so 
it can be powered from the single 12V supply). There is also STM32F072 MCU 
on the second board (it helps to save FPGA logic/pins).

You can find more information here:
https://github.com/UR3IQO/AngeliaLite

BTW, I have fixed one bug in the Angelia DHCP code - if Ethernet cable was 
unplugged and plugged in again the board failed acquiring IP address using 
DHCP (at least with my TP-Link Archer C7/OpenWrt router). The problem was in 
address renewal - if it fails DHCP client should start REBIND completely 
restarting DHCP procedure and it should send DHCPREQUEST using multicast 
address (the original code uses unicast address and fails to obtain DHCP 
address). See code/comments for details.

73!
Oleg UR3IQO