In message <000001bd6f0f$e7a22e00$362aa8c0@jupiter.dvp.com>, Peter Schultz writes >Hi All, > >I am facing a big challenge and before I will go ahead I would like to >ask anybody who has a good idea. >The solution not need to be cost effective. >I need to generate square wave with close to 50% duty cycle, >but quartz precision. >The frequencies are : 400Hz - 4KHz 10Hz steps > 4KHz -- 40KHz 100Hz steps > 40KHz -- 400KHz 1000Hz steps > 400KHz -- 4MHz 10000Hz steps > >I really appreciate any idea. This is trivial if you use a DDS chip like the AD9850, I have a web page describing a simple AD9850 system. The device actually generates a sine wave, but has on-chip circuitry to convert the output to a square wave. You'll find data on the ADI web site: http://www.analog.com You can use a PIC to control it. Leon -- Leon Heller: leon@lfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/dds.htm for details of my AD9850 DDS system. See " "/diy_dsp.htm for a simple DIY DSP ADSP-2104 system.