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DDS SOFTWARE The software used in this project was developed from the "siggen3a" program published on the NJ-QRP site www.njqrp.org . All credit and acknowledgement must go to Curt WB2V, Bruce AA0ED and Craig AA0ZZ. These people did the hard work of producing and documenting some fairly tough algorithms in the original program, I merely adapted their work. My thanks to George Heron, N2APB, for permission to publish this software. The modifications I've made include changes to the display software to overcome some timing problems and drive a 2 line LCD (the second line will eventually be used for a bar graph S meter), an IF offset function which shifts the DDS frequency (for use with the single carrier oscillator Belthorn SSB IF Module and it's ladder filter to give USB/LSB switching) and lastly the separation of the program into two separate programs running on separate PIC's linked by a serial interface. This last change was to speed up the tuning process by placing all the time critical DDS routines in one processor and the less time critical ,and slower, LCD routines in a second processor. Connectivity and overall program description is given in the text at the header of the listing. To use these files you will need a copy of MPLAB, a PIC Programmer and a PC. First make any modifications such as IF offset value using a text editor or MPLAB's editor. Then compile the file into a hex file via MPLAB. The hex file is loaded into the PIC using a PIC programmer and it's associated software. There is an enormous volume of information on the internet about programming PIC's and a wide range of programmers are available ready built or as kits. Data sheets and programming information for 16F84 are available on Arizona Microchip's (the manufacturer) website www.microchip.com . Downloads of MPLAB and other utilities are also available here. |