I keep seeing it while I'm reading up on using the PICs but I'm not sure I'm right in my understanding. If the pin gets any positive voltage at all no matter how small it will be high and if there is no voltage it is set low? is that correct?
No, there are specific trigger 'ranges', as with any logic family - below a certain voltage is 100% a zero, above a certain (higher) voltage it's 100% a one. Between those voltages shouldn't ever happen, and if it does the result is outside the devices specification.
PIC's usually have one or more pins with schmitt inputs, which prevent any such potential problems.
I want to use the PIC16f627 to make an autonomous robot taking inputs from my sensors, I just want to figure out what sort of signal I need to send to the inputs.
Sorry I'm a complete amateur at electronics, a comparator will check to see if an input is above or below a certain value, is that right?
Alright, I'll just wire it up when I'm ready and sure if it doesn't work I can go looking through the spec sheet then. If the PIC has a max voltage of 5.5V to power it, will that apply to the inputs too? Will a higher voltage through the inputs damage the PIC?
Okay I think I should be alright, I don't expect there'll be too much current from my battery. Sorry I just kept thinking of different things as I was talking to you. I'll try to post better question's in the future.
I keep seeing it while I'm reading up on using the PICs but I'm not sure I'm right in my understanding. If the pin gets any positive voltage at all no matter how small it will be high and if there is no voltage it is set low? is that correct?
Those are generalities, what exact voltage level those states are triggered at is far more complicated, temperature and manufacturing variance dependent.
Those are generalities, what exact voltage level those states are triggered at is far more complicated, temperature and manufacturing variance dependent.
I design a lot of analogue equipment and put analogue signals into the PIC and for a VCC of 5 volts the trigger level is always 2 volts. This varies very little with temperature and over batches of PIC's.
I should add I have worked professionally with PIC's since 1985 and worked for a PIC consultancy for 13 years.
The PIC is happy with analogue voltages on its pins.
On many occasions a mains reference was got simply with a resistor in series with a port.
I use PIC's monitoring the output voltages of analogue amplifers and have found them to be extremely reproducable and reliable.
Am I right to say that setting a pin high or low is an output then? If the chip is supplied with 5V will it send 5V out through an output? I'm sorry if these are stupid questions, I've only been playing around with PICs in my spare time for about three or four weeks now.
Am I right to say that setting a pin high or low is an output then? If the chip is supplied with 5V will it send 5V out through an output? I'm sorry if these are stupid questions, I've only been playing around with PICs in my spare time for about three or four weeks now.