I've decided to document the construction of my "STAR" transceiver. So far I've got the DSP and IF boards constructed, and still have to test and adjust them. I'm now assembling the Trxavrb controller board. I have a KS0108 192x64 GLCD I'm going to use as the display. Most KS0108 based displays have a pixel density of 128x64. The KS0108 can actually control up to 4096 pixels in no more than 64 rows or columns. So most displays based on this chip use two of them. The part has two chip select lines and can be set up for a display with up to 4 controllers. There are now some displays with three or four controllers having 192x64 or 256x64 pixels. (In theory a 128x128 display is also possible). As the Trxavrb firmware already supports the 128x64 KS0108 based display it will be possible to use the 192x64 unit as is (only using the left or right hand side of the display) and later I will modify the firmware to make full use of ALL of the display area.
I also have a "magic roundabout" mixer PCB from Glenn awaiting construction. I plan on designing my own BPF front end around the PA3AKE design. I will actually take this filter design and re-package it somewhat. I have enough surplus DPDT 12v dip relays for the job.
I also have a "magic roundabout" mixer PCB from Glenn awaiting construction. I plan on designing my own BPF front end around the PA3AKE design. I will actually take this filter design and re-package it somewhat. I have enough surplus DPDT 12v dip relays for the job.
3/2/2013 TRXAVRB
I obtained a blank PCB for the Trxavrb controller some time ago from Glenn VK3PE. The parts I ordered to 'stuff' it just came in from Mouser and Ebay and I've started to build it. As of today I've mounted a bunch of 0603 sized resistors (Damn you Glenn, those things are TINY!). I just mounted an ATmega640 for the "encoders-8" portion of the thing. The trxavr design actually used an ATmega2560 here, same chip used in the main portion of the controller. However, it's super overkill for the purpose as the encoders firmware uses under 16K of firmware. The ATmega640 fits the same footprint and is less than half the cost of the '2560. I'll have to recompile the firmware, but that will be the ONLY software mod required. Mounting those tiny 0.50mm spacing parts by hand is almost impossible to do without shorting adjacent pins, but a bit of fluxed solder wick cleans that up quick. It will probably take me a while to finish building the controller, as working with such small parts is very fussy work. If you try and rush it you will end up loosing many of the small parts, or worse, mix them up and never be able to sort them out again.
3/16/2013 TRXAVRB, Panel, etc
The Trxavrb is fully stuffed except for the voltage regulators. I've filled in some holes in my panel as I'm going to change the control layout a bit. I've wired up the 192x64 display to a 20 conductor ribbon cable with an IDC connector on it, ready to plug into the controller board. I still need to wire up the keypad and drill mounting holes in the panel for the spacers that will mount the controller board. Once I've got this done I can cut a piece of angle metal to serve as the heat sink for the two regulators. This bit of metal will conduct heat from the regulator IC's to the front panel, but I've got to get the board, the IC's and the mount all lined up just right. Once I have the board set up and cabled to the display, keypad, and main rotary encoder I can start testing it. I'll have to boot the PC up in windows to run Hobcat to configure the TRXAVRB software and load the eeprom with the DSP firmware.