AVR Project...Please help

[SeQueNceR]

Mahmoud Darweash...Geomatics and Remote Sensing Dep.

my graduation Project has a small Hardware Part.. which is far of my speciallity so i'm confused in this part... soo please help

i'm using the AVR90S8515

all i need a hardware which can

1- Interface with Serial (UART)
2- Drive a DC Motor in Bidirectional way
3- Read From a Limit Switch

i could develop the assembly of this project .. i'm just confused in the hardware design.... ca any one draw me a schematic with the componenets i may need ?? and the circuit diagram for it ??

i'm really thankful to you

 

[yogi]

interfacing AVR with computer,see the code
**broken link removed**

For driving motor in both directions use H-bridge
**broken link removed**

For Limit switch,make on port of AVR for input(let's be PORTC) DDRC=0x00; Connect switch to PortC and read switch status using int a, a=PORTC.



bibin john
www.bibinjohn.tk

 

[aupa]

I use Codevision and it has a wizard.
its very easy to program with it.

 

[SeQueNceR]

the port some time Read Logic On while no Voltage is applied ...how can i Solve This !!

 

[bamdad]

did you enable some sort of pullup on the pin or not? if you leave it floating, it will pickup some false signals...

 

[SeQueNceR]

i used this ciurcit as a pull up to extract Nosie .... but i still have noise .... when i used it for one Pin it worked ... when i repeated this Block 8 Times not all worked correctly .... the code i'm using to test is

.include"m8515def.inc"
.def temp = r16



.org $000
rjmp start

start:

ldi temp,$00
out ddra,temp

ldi temp,$ff
out ddrb,temp

ldi temp,$00
sei


main_loop:

in temp,pina
out portb,temp

rjmp main_loop

i'm using Atmega 8515

thanks in advance ... i'm online on Mahmoud_Darweash@MSN.com ... i'll be happy if any one Conacted me Online this will be easier ....

thanks

 

[nandhu015]

Hai

If the wires are long then it will pick up some noise, glitches, switching noise from power line and all. So use a filter. (.1 mfd).


I personally advise to have the switch in the other side. i.e. between port pin and ground. That will give you more noise immunity.

Regards
Nandhu