Do you have a question on Embedded electronics and controls? Ask our Expert, Paul Clarke

A diode will do the clipping of the negative cycle.

Otherwise, please elaborate.

Frank

yeah thanks for the reply i want to clip the even negative cycles in sine wave

Hi guys.

Im sorry if this post is on the wrong spot but it seems to me like this is one large post and everybody asks away.

Soo I was reading this post that eventually lead me here :  http://www.engineersgarage.com/embedded/pic-microcontroller-projects/adc-circuit

But i am a bit lost now since I copied and pasted the code exactly as is from the website and I get some errors.

The Delay_ms() gives errors but thats probably just my includes that are wrong but the other thing is on line 49 and some other places I have something looking like this

ADCON0|=(1<<GO);

The GO is wrong and I have no idea what it even should be...maybe a declared variable of some sort?

also on line 62 I have this function

void adc_init()

{

    ADCON1=0x0E;                            // Make RA0/AN0 pin as analog pin (Other pins remain to be digital I/O)

    ADCON0=0x00;                            // Select Channel0 & ADC off

    ADCON2=0x8A;                            // Left justified, 2TAD acquiciation time, Fosc/32 clock option

    ADCON0.ADON=1;                          // Enable ADC

}

but the last line  " ADCON0.ADON=1;                          " the ADON is redlined and I cant seem to figure that out aswell.

Please help and thanks allot that was the only tutorial that made sense to me.

thanks allor in advance and kind regards.

Cart

Hi Cart,

Looks like you have copy and pasted in some Microchip PIC code and my guess is its not for the same family of chip you have. Check the datasheet on Microchip for your device and it should help as the names will look simular.

Also I think again depending on your family of chip, you will find some pre-written ADC functions so you can use these to setup and read values back (but only on some devices).

Thanks

Paul

Hello Paul

I want to do a project work on Embedded systems.But i do now which topic to choose.i also want to publish a paper on it.But i do not know how to start.Pls could you give me some suggestions regarding this?

Please Sir I need Kiel uvision code for a 4 way traffic light

If it's part of your education are you not supposed to write it yourself ?

Try Google "c code 4 way traffic light" - enough to write a whole thesis there !

Michael Kellett

Hello Sir,

                Now i'm studying Embedded System C programming. Now learning ARM7 Microcontroller (lpc2148). After this course completed which course is benifit for me ?. What course is useful to my future ?....

Hi Paul,

Hope I am asking the right person....

I have been toying with the idea of an LCD project, and one part involves multiple small 1.5" LCD's.  These LCD's have been taken from those Photo Key Chains you all see, and they use an 8 bit parallel data bus (hope I am saying this correct).  Also each LCD driver has a CS (Chip select).

So here is what I want to do.....Have 5,10 or even more of these LCD's essentially all connected to a 8 bit serial BUS, each LCD would have its own CS line so I can write individually to each LCD.

First question - Is this possible?

Second question - Is there a limit to the number of LCD's I can connect to the BUS?  What are the potential limits and how would I overcome them?

Hope this is all clear.

Thanks

Mark

@winneymj

The limit is time and possibly chip (display) select lines.  All the 8 bit parallel data lines would be in parallel to all the displays, and the chip selects would fire sequentially to each display in turn allowing the 8-bit data to be written.  So the question turns into how fast can you write to each display so that it looks visually smooth and how many I/O do you have to do 8 data lines plus X-Chip Selects.

http://en.wikipedia.org/wiki/Multiplexing