I am building a simple pulse generator using an LTC6903 "synthesiser chip" and a few TTL chips. The range will be from about 0.1Hz to 68MHz and the frequency is set, geometrically, by a 15 bit control word. I will be using a PIC16F87 to control the synthesiser and drive a display. My problem is how to set the frequency by hand using the minimum panel hardware. I need control at the finest level, stepping the control register by one but also need to be able to make large frequency shifts quickly, perhaps stepping the register by 2^10 I have studied this for some time and come up with several solutions, non of them entirely satisfactory, but I would appreciate, in the first instance, suggestions which are not influenced by my thinking. --=20 __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .