thats a shcematic from somebody was using this interface with a 16F628 and a LCD i dont know if it works or not ...thats why iam asking if it works like that .
Sorry for butting in, on your thread prosound90. I am working on a similar req. for my project and was planning to use an LM35.
On the datashet the circuit below gives full range -55C to +150C
Could I confirm:
> If V+ is 5V V- is ground R1 should be 1K Ohms? ( -V == -5V? )
> I could hook up Vout directly to ADC pin on 16f877?
Sorry for butting in, on your thread prosound90. I am working on a similar req. for my project and was planning to use an LM35.
On the datashet the circuit below gives full range -55C to +150C
Could I confirm:
> If V+ is 5V V- is ground R1 should be 1K Ohms? ( -V == -5V? )
> I could hook up Vout directly to ADC pin on 16f877?
The time to take an analogue reading is only small, but as you say it will add up over time - but you shouldn't really be trying to run a clock in a software loop.
As you suggested, the answer is to use timer interrupts to run the clock, I would suggest you use tmr2, tmr0 has latency problems, and you have to correct for those. Another option is to use an external clokck chip, one of my tutorials uses a battery backed I2C chip from Philips, but there are various others.