A Microcontroller based Analogue Waveforms Analyzer Project - Page 2 - Electronic Circuits Projects Diagrams Free

Exo · 19th May 2004, 10:33 PM

Can't find it in ICprog...

This one does support it http://www.oshonsoft.com/picprog.html

samcheetah · 20th May 2004, 12:54 PM

Quote:

As I already mentioned (and you actually quoted!) the 16F628 uses EEPROM technology. I haven't tried any other software, but I seem to remember that someone mentioned that ICProg works with the 628A.

im sorry im so dumb i didnt read the post carefully.

okay so the 628 uses EEPROM technology and the 628A uses flash.

will Ozipic programmer work with the 628A? or is there only a need for changes in the software.

km · 20th May 2004, 06:03 PM

Hi Nigel 8)

I want to ask that which programming languages is a better option for me to program my PIC chip :?:

I have found out that Basic language is more easier to learn and master than either assembly or C language. Should I use Basic :roll:

Thank You!! :wink:

**Nigel Goodwin** · 20th May 2004, 07:32 PM

Quote:

Originally Posted by km

Hi Nigel 8)

I wanted to ask that which programming languages is a better option for me to program my PIC chip :?:

I have found out that Basic language is more easier to learn and master than either assembly or C language. Should I use Basic :roll:

Thank You!! :wink:

I would advise learning assembler, even if you eventually decide to use BASIC or C a knowledge of assembler is vital to make the best use of a PIC.

PIC assembler only has 35 commands (and many of those are rarely used), so it's not too hard to learn.

samcheetah · 21st May 2004, 08:01 AM

Quote:

PIC assembler only has 35 commands (and many of those are rarely used), so it's not too hard to learn

is that for all the PIC microcontrollers?

and if i want to learn the assembly commands of PICs where should i start from (in addition to your tutorials)

**Nigel Goodwin** · 21st May 2004, 08:46 AM

Quote:

Originally Posted by samcheetah

Quote:

PIC assembler only has 35 commands (and many of those are rarely used), so it's not too hard to learn

is that for all the PIC microcontrollers?

and if i want to learn the assembly commands of PICs where should i start from (in addition to your tutorials)

Not for all, that's for 14 bit core PIC's (the most popular ones), 12 bit core only have 33 commands, and (I think) 16 bit core have 55.

I would suggest printing the datasheet out for a start, the 16F628 is probably the best to start with (which I why I choose if for the tutorials). It also includes all the commands, along with lots of device specific information which is important to know.

I always think the best way to learn is by copying other peoples code, and modifying it to make it do what you want. That's the basis behind my tutorials - by modifying existing code (and finding out it doesn't work anymore!) you learn a lot about how it works. It's very gratifying when you do actually get your mods to work :lol:

One big problem with anything program based, is when it doesn't work - is it a hardware problem?, or a software problem?. This is why I give veroboard layouts, and proven working software - by building exactly as shown, and using my routines, it WILL WORK. Then when you modify it, you know the hardware is OK - as you've already seen it working.

samcheetah · 21st May 2004, 12:47 PM

thanx alot Nigel for that very informative and inspiring post.

these days im close to having my end terminal examinations. the moment i get free from my exams ill start with the 16F628.

i just cant wait to start playing with PICs :lol:

km · 22nd May 2004, 09:46 AM

Quote:

PIC assembler only has 35 commands (and many of those are rarely used), so it's not too hard to learn

Are you mean these 35 commands from the figure below? :roll:

**Nigel Goodwin** · 23rd May 2004, 09:29 AM

Quote:

Originally Posted by km

Quote:

PIC assembler only has 35 commands (and many of those are rarely used), so it's not too hard to learn

Are you mean these 35 commands from the figure below? :roll:

Yes, they are the ones 8)

If you look at my first tutorials you will see how few of them you need to actually do something.

km · 23rd May 2004, 04:02 PM

This is the circuit that I found on the internet. Its purpose is to ensure the input voltage to the ADC falls between 0 to 5V. 8)

From the figure below, the first op-amp is designed to change the input voltage so that it does not go over zero volts, for example changes -2.5 to 2.5V, to -5 to 0V. The second op-amp is configured in negative amplifier mode with a gain of unity changing -5 to 0V to 0 to 5V. The third part with the two diodes is for protection, e.g. say a -1 to 6V signal makes it through the op-amps the diodes will cut off the peaks of the waveform making sure no damage is done to the A2D.
:arrow:
Can this circuit able to operate for the largest input voltage range -250V to 250V :?:

Is this circuit sufficient for my project at the input stage? (to step down the input voltage to 0-5V) :roll:

Should I used any variable resistors? :!:

Instead of 3 inputs, can I have only one? (i.e. to select different range of voltage) If can, HOW? :idea:

Quote:

Just remembered something I forgot, you will need a low-pass filter on the input stage, it's vital that your sampling rate is higher then the maximum incoming frequency - at least double, preferably more!. Otherwise you get anti-aliasing distortion which will complete ruin any readings.

The low-pass filter that Nigel had mentioned, where do I need to put? Before this circuit OR between this circuit and the A2D?

**Nigel Goodwin** · 23rd May 2004, 04:21 PM

Quote:

Originally Posted by km

This is the circuit that I found on the internet. Its purpose is to ensure the input voltage to the ADC falls between 0 to 5V. 8)

From the figure below, the first op-amp is designed to change the input voltage so that it does not go over zero volts, for example changes -2.5 to 2.5V, to -5 to 0V. The second op-amp is configured in negative amplifier mode with a gain of unity changing -5 to 0V to 0 to 5V. The third part with the two diodes is for protection, e.g. say a -1 to 6V signal makes it through the op-amps the diodes will cut off the peaks of the waveform making sure no damage is done to the A2D.

If you're using a PIC A2D, you don't need the protection diodes, they are already built-in to the PIC.

Quote:

Can this circuit able to operate for the largest input voltage range -250V to 250V :?:

Yes, no problem - but make sure the 100K resistor on the input is suitably rated.

Quote:

Is this circuit sufficient for my project at the input stage? (to step down the input voltage to 0-5V) :roll:

Yes.

Quote:

Should I used any variable resistors? :!:

As long as you use 1% resistors, you shouldn't need any.

Quote:

Instead of 3 inputs, can I have only one? (i.e. to select different range of voltage) If can, HOW? :idea:

Just include the input resistors for the value you want, leave the rest out.

Quote:

Just remembered something I forgot, you will need a low-pass filter on the input stage, it's vital that your sampling rate is higher then the maximum incoming frequency - at least double, preferably more!. Otherwise you get anti-aliasing distortion which will complete ruin any readings.

The low-pass filter that Nigel had mentioned, where do I need to put? Before this circuit OR between this circuit and the A2D?

You could make the second opamp stage into a lowpass filter, as long as it inverts - if you use a non-inverting filter, you could add it either before or after the second opamp.

km · 24th May 2004, 05:43 PM

Sorry!! I think I have missed out some qustion. :shock: For the analogue circuitry diagram (as shown in previous post), is it necessary to include the capacitor C1 in the circuit (last part of the circuit)? If YES, is it acceptable for 100µF?

As for the low pass filter - RC circuits, is it acceptable for R=1000kΩ & C=1µF ? If it is not acceptable, can you please suggest suitable values for me? Is the resistor for the RC circuit has to be 1% resistor?

Thank You!! :wink:

**Nigel Goodwin** · 24th May 2004, 09:19 PM

Quote:

Originally Posted by km

Sorry!! I think I have missed out some qustion. :shock: For the analogue circuitry diagram (as shown in previous post), is it necessary to include the capacitor C1 in the circuit (last part of the circuit)? If YES, is it acceptable for 100µF?

100uF would be far too big, you don't need a capacitor there at all, a PIC A2D already has a sample and hold capacitor.

Quote:

As for the low pass filter - RC circuits, is it acceptable for R=1000kΩ & C=1µF ? If it is not acceptable, can you please suggest suitable values for me? Is the resistor for the RC circuit has to be 1% resistor?

It all depends on how fast you are going to read the incoming signal, a simple resistor capacitor filter is probably not good enough, you should make the 2nd opamp into an active filter at about 1/5th of your sampling rate.

km · 25th May 2004, 06:22 AM

Thanks for your advice, Nigel!! :wink:

Quote:

100uF would be far too big, you don't need a capacitor there at all, a PIC A2D already has a sample and hold capacitor.

I used PIC 16F628 (without a built-in A2D), so is it means that I don't need the capacitor as well? I'm using an external A2D (TLC 548).

**Nigel Goodwin** · 25th May 2004, 08:01 AM

Quote:

Originally Posted by km

Thanks for your advice, Nigel!! :wink:

Quote:

100uF would be far too big, you don't need a capacitor there at all, a PIC A2D already has a sample and hold capacitor.

I used PIC 16F628 (without a built-in A2D), so is it means that I don't need the capacitor as well? I'm using an external A2D (TLC 548).

If you check the datasheet it will tell you, as far I know it should have an internal sample and hold.

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19th May 2004, 10:33 PM	(permalink)
Exo	Can't find it in ICprog... This one does support it http://www.oshonsoft.com/picprog.html

20th May 2004, 06:03 PM	(permalink)
km	PIC Programming Languages Hi Nigel 8) I want to ask that which programming languages is a better option for me to program my PIC chip :?: I have found out that Basic language is more easier to learn and master than either assembly or C language. Should I use Basic :roll: Thank You!! :wink:

21st May 2004, 12:47 PM	(permalink)
samcheetah	thanx alot Nigel for that very informative and inspiring post. these days im close to having my end terminal examinations. the moment i get free from my exams ill start with the 16F628. i just cant wait to start playing with PICs :lol:

24th May 2004, 05:43 PM	(permalink)
km	Confirmation Sorry!! I think I have missed out some qustion. :shock: For the analogue circuitry diagram (as shown in previous post), is it necessary to include the capacitor C1 in the circuit (last part of the circuit)? If YES, is it acceptable for 100µF? As for the low pass filter - RC circuits, is it acceptable for R=1000kΩ & C=1µF ? If it is not acceptable, can you please suggest suitable values for me? Is the resistor for the RC circuit has to be 1% resistor? Thank You!! :wink: