shiftOut Method?

[mhepp]

Dear all:

I am trying to control a AD9851 DDS [1] with a MicroPython board. Now, is there a function for sending byte data via a data and clock pin, same as the following Arduino function:

https://www.arduino.cc/en/Reference/ShiftOut

?
Basically, what I need to do is sending a 40 bit value to a chip using a clock and a data line.

On an Arduino, this can be neatly done like so (taken from [2]):

Code: Select all

digitalWrite(LOAD, LOW);
shiftOut(DATA, CLOCK, LSBFIRST, tuning_word);
shiftOut(DATA, CLOCK, LSBFIRST, tuning_word >> 8);
shiftOut(DATA, CLOCK, LSBFIRST, tuning_word >> 16);
shiftOut(DATA, CLOCK, LSBFIRST, tuning_word >> 24);
shiftOut(DATA, CLOCK, LSBFIRST, 0x09);
digitalWrite(LOAD, HIGH);

Before I implement it on my own, I wanted to make sure there no such thing as a built-in.

Thanks for your hints!

Martin

[1] http://www.analog.com/media/en/technica ... AD9851.pdf
[2] http://blog.marxy.org/2008/05/controlli ... 2285642730

[Roberthh]

As far as I understand the manual, you can use SPI for that purpose. In addition, you need to connect the FQ_UD line and Reset. After resetting, you'll need to switch the AD9851 to serial mode. Since thar requirfes toggling the Clock line once, you might have to set the clock line first as Pin output for a manual toggle, and then enable its use as SPI Clck.

[mhepp]

Thanks, Robert! Will try that!
Martin

[cefn]

This reference code was used for a Jack-in-the-Beanstalk animation as part of our Minilluminations, in case you need a reference version of working (but basic and not performant) ShiftRegister code...

https://github.com/ShrimpingIt/tableaux ... lk/main.py