Matrix user forums

Hi

I am running the free trial of Flowcode V5 and want to know if I can use it to bring an led from off to full brightness over say 0.5 second ?
I think this would be done using PWM which is built into the PIC I am using 16F628.
If I know it can be done I can purchase the full program.

Thanks, Dave

Hi

It can be done in FCv5 very easily. If you want we can send you hex file so that you can test and decide to buy professional version.

If you could that would be very kind.

ok. No problem. I'll post to-night.

Hi

Here is the code promised. The LED need to be connected to RB3<PIN9 of PIC16f628> through 470 ohm resistor and crystal has to be external for this code which is 4MHz should be connected to 15 & 16 pin. But if you want I can tell you how to use internal clock if you need.

Hi Enamul

It was very kind of you to send me the code, I will try it out.
The bit I wanted to see most was the Flowcode you also sent, but the free trial I am running is limited to just a few PIC devices, my PIC not being one of them. So it will not let me see your flow chart. Would it be possible to send me a screen shot image of the Flowcode flow chart ? That will tell me everything I need to know before purchasing the software.

Thanks, Dave

Hi

Here is the screen shoots..

Hi Enamul

I very much appreciate your help with this, thank you Dave.

Hi Enamul

Thanks to your help I have purchased Flowcode 5 (Home) and have successfully designed my PIC and circuit so the led dims up, holds 100% then dims down, look great.
I was wondering if it was possible to add a light level detector to an input of the PIC, 16F628, so as to run the LED only when it was dark.

Dave

Hi Dave
have a look at this link http://www.matrixmultimedia.com/mmforums/search.php

you should find something in there
Regards
Dazz

There are several solutions for light level detection. One (simplest?) is to use a LDR connected to an analog input. Use the ADC component to read the input.

Wiring:
Resistor value depends on LDR characteristics. Try different values or use a potentiometer.

Hi kersing

I like your suggestion, very much what I had in mind.
So do you think I can connect this to PIC 16F628 ?
I guess if I can it would be to pin 17 or 18 AN0 / AN1.

Dave

Hi Dave
if you follow the link and type ldr in the box there are a few good posts with examples, if your feeling adventurous theres also some post on using an led to sample light got a few crude ones up and running

Regards
Dazz

Hi Guys,

Be aware that the 16F628a does not have an ADC, only comparator inputs!
I'm sure they'll be a snippet of code somewhere on here to do the light level detection with the comparator.
See post regarding 16F628a: http://www.matrixmultimedia.com/mmforum ... 46&t=10681

...and...

Welcome to the forum Dave!

Regards

Brian

Hi Brian

Thanks for the welcome. I am enjoying programming up my first PIC.
I think light level detection with the comparator is just what I am after.

Dave

Hello,
I can only see one pwm for 16f877a. I know there are two pwms for this chip. This has to be a bug or restriction in trial version?

greentech wrote: I can only see one pwm for 16f877a. I know there are two pwms for this chip. This has to be a bug or restriction in trial version?

No restriction on PWM with Trial version.

Do you mean you have set flowchart up correctly but can only see PWM on one of the hardware channels only
Or
You can only see one channel within your flowchart?

If the latter, then I have posted information on how to create more than 1PWM channel with Flowcode V5 here:
http://www.matrixmultimedia.com/mmforum ... 26&t=11694

Posting your Flowchart could help us to solve your issue more quickly.

Martin

here is a screenshot. i cant c 2nd pwm in component macro and over panel.

You need to add another PWM component, since you need to add an additional PWM component for each extra PWM channel your using.

E.g if your using 4 PWMs, you need to add 4 PWM components in total.

Martin

Aah! Silly me. i was used to fc4
Sorry guyz, got it now.

No worries greentech these things can catch you out if use to a different way.
Just remember to set both PWM components with the same settings:
http://www.matrixmultimedia.com/mmforum ... 570#p43570

I have altered the above post to mention about a requirement to add additional PWM pomonents, so you have helped other people out, by bringing it to my attention.

Thank you for that

Keep up the good work brainiacs.

i am trying to understand how to init 3 level pwm to obtain 50Hz sine output. I have to use pic16f877a. i also need to put some lcd functions voltage readings from mains and battery etc.

How can i invert the pwm for pushpull loads.

Hello,

I have posted a reply here.
http://www.matrixmultimedia.com/mmforum ... 29&t=12071