pike said:
hey guys,
I am having trouble trying to get the internal oscillator of the 16F819 to actually work.
Do I need any commands in the program to calibrate or startup the oscilator?
I'm using IC-Prog for now and it gives me the option of :LS, HS, XT,EXT Clock, IntRC, IntRC Clockout, ExtRC and ExtRC Clockout.
-I know I should use either IntRC or IntRC Clockout. But whats the difference between the 2 and which one do I need???
Both settings activate the internal RC oscillator. But IntRC clockout outputs the frequency generated by the intOsc on a certain pin (see datasheet to see wich one). This allows you to use this frequency elsewhere in your circuit. The normal IntRC setting does not output the frequency, in stead the pin is a normal I/O line
pike said:
I also have the options of using fuses:
watch dog timer
The watchdog timer runs in the background. Your software must reset the timer at certain intervals (with a CLRWDT command). If your software fails to do so in time (because it is stuck in an infinite loop for example) the watchdog timer will overflow and this will reset the pic. If you turn it off then there is no need for CLRWDT commands in your code
pike said:
When power is applied to the pic it will wait a short time (less then half a sec) before it starts running. This could come in handy if there is equipment connected to the pic that needs time to stabilize when power is applied (a LCD for example).
pike said:
With master clear switched to external you can reset the PIC at any time by driving the MCLR pin low (see datasheet to know wich pin is MCLR). To make the pic run you must pull MCLR high.
With master clear switched to internal you can no longer reset the pic from outside (of course, if you turn the pic off and back on it is also reset)
but the MCLR pin can now be used as a digital input pin.
pike said:
When supply voltage drops below a certain voltage the pic may start acting weird due to this voltage shortage. To prevent this you can enable brown-out. With brown-out enabled the pic will keep resetting itself as long as the supply voltage is too low. Once the voltage is restored the pic will start running again.
pike said:
debugger option sets some pins on the pic so they can be connected to an in-circuit debugger device wich allows you to monitor what the pic is doing wile it is running. The pins will be no longer available as normal I/O lines
pike said:
-So how do i get my internal oscillator working??? (well how did you guys get your working)
just set your fuse settings to INTOSC RC