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# AD7730 to interface 10ton load cell with 2mV/V specs

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#### ex4

##### Full Member level 2
Anybody has tries AD7730 to interface 10ton load cell with 2mV/V specs??
:?::?:
Is it can count to 1 kg resolution without any external amplification ??

for my load cell 1uV/kg
can it be done without any external amplifier???
i calculate from the datasheet, that i can get 4 count for 1uV using only that chip

this is c code for AVR for AD7730 ,can be used for other micros by simple changes.

Points: 2

Points: 2

### mitros

Points: 2

HELLO!CAN U EXPLAIN CLEARLY IN THIS PROGRAM ? I DONT UNDERSTAND ?EX:
this code ?
{
//Set SS high --- Set SS, MOSI and SCK as outputs
SPCR = (1<<SPE) | (1<<MSTR) | (1<<CPHA) | (1<<CPOL) | (1<<SPR0); //Enable SPI in Master mode, mode 3
}
i dont know command code "1<<SPE" ,what is it mean ?

have you seen any examples on C coded for AVR??? check the Datasheet!!!!!

SPE is a bit of the SPCR register... as in avr-gcc you can't access individual bits directly... they use the 'bit value' aproach...

some example:

say SU equals to 3 so we mean to turn on only the bit3

we want this REG = 0000 1000 , right?

00001000 binary equals to 8....

which is the relation between 8 and 3 ???? of course power_of_2 !!!!! 2^3 = 8

in binary, there is a more easy approach of power_of_2 ... it's called shifting...

so we shift one bit theree times...

we have 1 bit only:
0000 0001

... and shift it three times!

0000 0010
0000 0100
0000 1000

now we have the 3th bit activated!!!!

the shift operation in C is ..... << ....

so....

REG = 1<<SU ; from my lil' example...

SPCR = (1<<SPE) | (1<<MSTR) | (1<<CPHA) | (1<<CPOL) | (1<<SPR0);

means: on the register SPCR, set the bits SPE, MSTR, CPHA, CPOL and SPR0 and clear the rest...

if you don't know wtf does each bit... you must read the datasheet troughfully....

shahab_taheri

Points: 2