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HPSDR – Atlas and Ozy

Last friday, I went to the market and found this nice shop called Melody Electronics which is right outside all the chaotic SP road. The shop keeper is nice and carries all kids of SMD parts and other stuff. I bought replacements for my damaged tip and afew jumpers.

The first thing I did was to power-on the Atlas from the surplus computer SMPS I had in my shack. Earlier I had purchased one to see if I can modify it to make a 13.6 volts bench power supply. I never really proceeded with that experiment, so that purchase came in handy. Atlas worked without any issues. All five LEDs were lit and voltages were also fine. Here is a picture:

Atlas 01

One caveat though. TAPR ships Lite-On LEDs with the kits. The parts list for the HPSDR projects also use Lite-On SMD LEDs. They have two series of LEDs one is the C170 series and another the C171 series. There is a distinct mark which one can see on one end of the LEDs. This is cathode generally. This holds true for both the series except for the C170 RED LEDs. For that, it is exactly opposite. It is really surprising that manufacturers are still confusing the customers with such stupidities.

Next was Ozy. The good thing was that I had in hand all the parts except the DB25 connector. Since I have a collegue who can do soldering with fine pitched components, I got the FX2 and Cyclone chip soldered on the bare board by him. He did a marvelous job.

The entire Ozy board has many jumpers to make it flexible. Most of the signals are routed thru the Atlas. The entire system has many I2C devices, many CPLD/FPGA on it.

Ozy with only FX2 and FPGA

Now, yesterday I spent almost all of the day time working on populating the board. It was great fun working thru the board. Phil N8VB and Lyle Johnson KK7P have done really great care to make it a fun filled board. I had some surprise towards the end of yesterday. I discovered those resistor packs and RC packs. These are lead-less packages and there were many of them to be soldered. These are on the paths of Ozy – Parallel/serial port or in Ozy – Atlas paths. SO I haven’t really tested whether my soldering worked yet. But these are crucial. I would rather use a regular 0603 part rather than optimize on size by using resistor packs. They are very homebrewer-unfriendly. :-)

Ozy with most parts populated.

Almost the whole board was complete yesterday, but I had to go out and didn’t want to start again in the night. Today morning, I populated the rest and the end result is this board. You can see that the DB9 and DB25 connectors are not yet in. I should probably fix it now.

ozy 03

The next step was the real test. I hooked up the board on the Atlas backplane without connecting the USB cable and powered up the unit. The D12 LED lit up. No smoke. I checked the regulators. None of them are getting hot.

ozy on atlas

Next was to see if the FX2 enumerates properly. HPSDR folks are mainly Windows users and so the software currently works only on windows, though the entire software (including host side software, firmware, FPGA code etc) is Free Software. Since I have a work laptop which runs windows, I connected the USB cable to it and alas, windows found a USB device. I used the libusb drivers provided and FX2 came up with its default VID and PID. Next was to see if firmware can be downloaded into the FX2. I ran the initozy11.bat file provided with the powerSDR SVN and the LEDs light up beautifully. The LEDs D1-D4 were off, D5-D8 was ON, D9 and D10 were alternatively ON and OFF, D11 was off and D12 was ON. And it looks like this is the right way. So, I have a working FPGA development system now and without additional components (either Janus or Mercury), it is just that – an FPGA development system. So, till I get my hands on Janus, I am going to play with the system. Also on my list of things to do is to get a hpsdrctl program on GNU/Linux which is nothing but an equivalent of the usrper program in the GNU Radio, which can be used to control the Ozy board and later other boards too. The code is all there in the HPSDR SVN. Just have to integrate the pieces together. Also of high priority is to work on a USB Blaster emulation.

Once Janus is in, I plan to use it with the one of the inexpensive Softrock TXRX kit as my day-today radio. I am also considering a buying used laptop dedicated for SDR use. But they are not really cheap yet.
Help from the folks at HPSDR were invaluable and I learnt a lot in the process. Horst provided some excellent documentation.