74F675A problem

hello,
i trying output 16 bits 74f675a.

i using tutorial.
i connected:
si -> d2
shcp ->d3
stcp ->d5
cs -> 5v


i cant make chip work.

where'd find chip? thought had been obsoleted.

anyway, defining pins following names on page 2 of datasheet:
si = datapin
shcp = clockpin
stch = latchpin
cs = chipselect
rw = connect gnd write usage
then write data part:

code: [select]


digitalwrite (chipselect, low); // select part data transfer
digitalwrite (latchpin, low); // set move data output register

shiftout (datapin, clockpin, msbfirst, highbyte (your_int_data) ); // shift in data
shiftout (datapin, clockpin, msbfirst, lowbyte (your_int_data) );

digitalwrite (latchpin, high); // move data output register on low high edge
digitalwrite (chipselect, high);  // deselect chip

a potential problem serial data clocked in clockpin going high low.
would have @ how shiftout() written , see if equivalent of this:

digitalwrite (datapin, next_data_bit);
digitallwrite (clockbit, low);
digitalwrite (clockbit, high);

and if you'd okay.

i prefer use spi.transfer() , use atmega hardware shift stuff out faster, think has mode lets select data valid on falling clock edges, instead of rising clock edges.

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