My first PIC Project. Voltmeter and another thing

[iflymyhelishigh]

Hi guys, I am currently starting out with PICs and have a couple of PIC16F628As.

I currently want to build a voltage display (0-12) and have a startup beeper, hehe

I know that for the voltage display, I need something like a 78L05 or something.

My project is converting an old HardDrive case into a variable voltage lab supply. I am planning to do an analog 317T voltage regulation, and have a PIC do the rest.

I want a startup beeper. If some of you remember, I posted back in the general about a startup beeper, but I truely didn't like that beeper lol.

Also, if its possible to have it have a short burst when I hit certain voltages like, 5V, 12V etc.

 

[Nigel Goodwin]

Hi guys, I am currently starting out with PICs and have a couple of PIC16F628As.

I currently want to build a voltage display (0-12) and have a startup beeper, hehe

Well dump the 16F628, as it doesn't have analogue inputs - use a 16F88 or 16F819, assuming you want to keep to the same size PIC?.

My tutorials show how to use the analogue inputs.

 

[iflymyhelishigh]

Which one of those 2 do you recommend?

 

[Nigel Goodwin]

Which one of those 2 do you recommend?

Either would be fine, but the 16F88 is probably the slightly more modern one?.

 

[iflymyhelishigh]

It has 16 I/O pins, is it compatible with LCDs?

 

[Nigel Goodwin]

It has 16 I/O pins, is it compatible with LCDs?

Assuming you mean LCD text modules?, then ALL PIC's (with enough pins) are compatible with them.

 

[Tightwad]

I am looking to do a similar function, along with learning about PICs in general. I have been studying Nigel's Tutorial, and getting prepped to build the Main board and the LED boards to gain an understanding before I try anything too complex...would it be best to just skip to the 16F88 over the 16F628A? I was just about to buy the 16F628A but will get the 88s if they will work for the tutorial.

 

[Pommie]

The 16F88 is a much better chip than the 16F628. however, for Nigel's tutorials it is not ideal as you need to add additional instructions (clr ANSEL) and the config will need changing. Both are fairly simple changes and easily implemented if you are willing to make the changes.

Mike.

 

[Nigel Goodwin]

Buy both chips, they aren't expensive, and it's worth having both.

That way you can build the tutorials as shown, then change to the 16F88 and make the required very small changes - and the changes are very small.

 

[Tightwad]

Thanks, I will take the advise and buy both. I am starting from ground zero, but with high hopes for what I can learn. On your boards you have capacitors, but you don't specify the size...what size is suggested?

 

[Nigel Goodwin]

Thanks, I will take the advise and buy both. I am starting from ground zero, but with high hopes for what I can learn. On your boards you have capacitors, but you don't specify the size...what size is suggested?

Do you mean the voltage? - as long as it's higher than the supply it doesn't matter.

 

[Tightwad]

Voltage and capacitance(micro-farads?) both. I assumed voltage would be higher than source, but didn't know if capacitance was important.

 

[Nigel Goodwin]

My diagrams have the values on them, which one are you talking about?.

 

[Tightwad]

You are correct, somehow I totally missed the values there. Thanks!