initial miniPIG+ specifications filed on Sunday Sept 30 2010 updated and partially condensed on Sunday Oct 17 2010 added email comments on Thursday Oct 21 2010 ----------------- start of spec -------------------------------------------- These specs are for two versions of the miniPIG A. a 2 band version with plug-in modules. This version will be designed for field and home qth use. We will use low power circuits whenever possible, without sacrificing performance. B. a home qth version where size and power are not important. This will be the same base design as the 2 band version but has all bands on the motherboard. Emphasis will be on open physical design to encourage experimenting. All parts used in the design of the miniPIG must be currently available parts stocked at outlets such as Mouser and/or Digikey or we must have a reserve stock of enough parts to built 500 miniPIG. 1a. VXO - VCO - VFO - RIT - XIT 1b1. ATmega328 cpu 1b2. ATmega644PA cpu 1c. AD9834CRUZ DDS 1e. Freq Readout LED backlit 16x2 LCD or better 1f. mechanical/optical rotary encoder with optional two push buttons for up/down 2a. CW - YES! 2b. SSB - YES! 2c. AM - Maybe 3. 600 meter band - 461-469 kHz and 471-478 kHz 3a. 1.8 - 29 MHz all ham bands if possible 3b. will explore 6 meters but I doubt it will make it into the final spec 5. QSK - Full; use MPN3700 PIN Diodes or 1N4007 diodes 6. Attenuator - 10 dB and/or 20 dB 6a. two antenna ports that can be switched rapidly from the front panel 7. Omron Relays for band switching use G6SU-2 (active part mouser $2.50) 7b. diode switching of Band Pass Filters 7c. provisions for running transverters 8. preamp - 2N5109 Norton? receiver must benchmark with K2 ... sensitivity and dynamic range 8a. preamp on/off 9b. Diode Ring, front end mixer - HSMS-2829(Mouser) and probably BN-43-2402 10. postamp - 2N5109 11a. CW Filter - 4 or 5 pole crystal fixed bandwidth - PCB will accomodate varactors for mods 11b. SSB Filter - 4 or 5 pole crystal fixed bandwidth - PCB will accomodate varactors for mods 12a. IF Amp - MC1350 12b. IF Freq - 5.0688 MHz 12c. buffered output on the IF to allow easy attachment of external devices 13. AF Detector - NE602A or ??? 13a. SCAF filter optional 14a. Audio Amp - TDA7052AN see http://www.wa0itp.com/tda7052b.pdf [see SPRAT #142] 14b. Audio Amp - discrete homebrew design using NE5534AP 14c. sidetone - twin-T oscillator with adjustable volume 14d. Audio filtering? 15. AGC - Audio derived or IF derived or both 15a. AGC control (fast/slow/off/manual) 15b. S_Meter 16. Keyer - from K1EL or we design our own in firmware 17. LCD backlight on/off 18. 12 ot 16 button keypad 18a. audio feedback indicating selected keypad functions RF Amp Circuit 1. PN2222A pre-driver 2. Drivers - two 2N2219A push-pull 3. Finals - two RD16HHF1 push-pull - http://kitsandparts.com/RD16HHF1.pdf 4. mount the MOSFETS on the edge of the circuit board then it can be heat sinked to what ever enclosure is used 4a. will require additional heat sink for 20 Watts out 5. output power must be adjustable from the front panel 5a. Control of the RF power amplifier to select class C or AB. 5b. wind RF out transformers for 5 or 20 watts 6. on-board HIGH RESOLUTION SWR or relative FWD/REV power circuitry - No LEDs large footprint case/enclosure for home qth version semi-watertight enclosure for field 2 band version The Ten-Tec TG-38 case is 8.25" W x 3" H x 6.125" D. At $13.40, it is likely one of the least expensive metal boxes in that general size. The Ten-Tec TG-38 case is too flimsey and too small for this project. http://www.tentec.com/?s=enclosures#standard-enclosures Free schematic software from http://expresspcb.com Schematic tutorial http://w8diz.com/qq-fc-project/part-2/part-2.php Production PCBs from http://expresspcb.com --------------------- end of spec ------------------------------------------- I think there are really two parts to this and Hanks reasoning includes both but doesn't separate the functionality. One being an audio interface (AKA soundcard funcationality) and two being control functionality (AKA serial port). In the end, one USB connector but two functional blocks accomplished by a two (or more) port USB hub, USB CODEC (i.e PCM2702) and USB serial interface (i.e. FTDI). We could have one or the other or both and both are more or less "plug and play" modules in their own right but each require a finite amount of board realestate to implement. My preference would be to provide both functions perhaps as a plug in option and it you went down the road of integrating a two (or more) port USB hub then one or both (or more) USB options could be plug in options. Graham ve3gtc ----------------------------------------------------------------------------- I was thinking some sort of a user interface via the com port - Paul, AA9GG ----------------------------------------------------------------------------- > We may be able to put a "hook" onto the CPU for a USB interface > and leave it to the software gurus to implement it. - Diz, W8DIZ ----------------------------------------------------------------------------- Maybe an FTDI chip ( http://www.ftdichip.com/Products/ICs/FT232R.htm ) We use them in a current product and they work quite well. By putting a boot-loader in the micro we can do firmware updates to the micro via USB - Paul, AA9GG The ATmega644 has a TTL serial com port on it. The FTDI chip will easily convert it to USB. I was thinking using it more for firmware changes(via bootstrap) and de-bugging purposes. - Paul, AA9GG It's VERY simple to use. The on-board USART of the '644 direct connects to the FDTI chip @ 9500/N/8/1 (default), USB on the other end. The FDTI chip does it all. It is a USB to serial converter chip. - Paul, AA9GG ----------------------------------------------------------------------------- I really, really hate having to use a menu when operating a rig. They are great for many set up features that do not change very often. But things like CW speed, pitch and volume need to be there, on the front, with a knob for people to grab and twist! Ditto all the other often used controls like xit/rit, vfo's, ant-a/b and other such things that may (or may not) be used in the final build. And the front panel needs to be large enough for full sized hands and fingers to have access to all those knobs and buttons! :-) Ron, KU7Y ----------------------------------------------------------------------------- A mechanism for Firmware Updates are a MUST HAVE item that will be implemented. - Diz, W8DIZ ----------------------------------------------------------------------------- there should be a header for updating firmware via USB or com port - Tim W4Yn ----------------------------------------------------------------------------- Networking and USB both can be very simple if you use the "right" part. For example there is a $10 microcontroller the Atmel "AT91SAM7X128" that contains a integrated Ethernet, USB and CAN interface, is based on the 32-bit ARM7TDMI RISC processor. It features 128K bytes of Flash That is a lot of on-chip integration. Also the 32-bit CPU is very easier to program compared to the smaller chips. You can write in "C" and not worry to much about how much space you are using. This was just an example, to avoid using that scarry 100 pin chip pick some thing that has ALL the features you need on-chip. So network, USB, or "whatever". don't bother with external controller chips. Find the uC that already has that interface on-chip Chris Albertson ----------------------------------------------------------------------------- Designing for testability must take place along with the actual circuit design-- it's difficult to add in later. - Brad, AA1IP ----------------------------------------------------------------------------- ref Arduino! http://www.arduino.cc/ - Graham ve3gtc ----------------------------------------------------------------------------- Check this out. http://www.picoweb.net/ - Paul, AA9GG ----------------------------------------------------------------------------- I kind of like using the DDS directly, in the interest of simplicity and cost. But I'm not sure how much the DDS / PLL approach gains you in freedom from birdies and spurs. Is it worth it? Not sure. And are PLL chips that work below 30 MHz getting scarce? I'm liking 8 MHz for an IF frequency these days, maybe for availability of cheap crystals for filters & BFOs. - Nick, WA5BDU ----------------------------------------------------------------------------- FYI....AVR Bootloader info: http://hubbard.engr.scu.edu/embedded/avr/bootloader/index.html - Paul Mateer, AA9GG -----------------------------------------------------------------------------