Even more than the speed you run the PIC at, the compiler makes a big difference. Some BASIC implementations compile the program to a bytecode that is stored in the EEPROM and interpreted by code running in the PIC. This is obviously orders of magnitude slower than true compiled code. Once you have figured out that you have actual compiled code, you can still change the performance by orders of magnitude depending on how competent the compiler is. However, if the PIC were running in the megahertz range, and the compiler was 'pretty good', I would expect you could flash the LED at a kilohertz kind of rate. If your PIC had a 4 MHz or igher clock, and you did nothing in the loop besides turn the LED on and off, I would not expect you could see the LED flash unless the compiler was very poor. Obviously, you could choose to clock the PIC at 32 kHz instead of 20 MHz, and that would make a huge difference. And the compiler could be lame, and .... and .... and ... --McD ----- Original Message ----- From: "R. I. Nelson" To: "Microcontroller discussion list - Public." Sent: Monday, November 28, 2005 2:19 PM Subject: [PIC] newbie question on timing > Using a basic compiled program using a for-next loop, a flash PICchip. > can I expect toget a pulse every 55 ms. or about 18pulses per second? > > I know a lot of it will depend on what speed I am running the chip at. > > -------------------------------------------------------------------------------- > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist