Shiftin with external Clock howto ?

[RFsolution]

Hi all

I have an excisting piece of hardware which is controlling a 12bit DAC7611

The DAC 7611 gets the clock from the excisting hardware,Data and Load/ , CS/ is wired low,
CLR/ is wired high

I want to read the value (0-4096) which the excisting hardware is sending and display it on an LCD

Anyone who can point me how to do so ?

I noticed that shiftin is generating it's own clock so that is not an option

Looking forward

[aerostar]

What I think you need to do is "eavesdrop" on the clock and data line.

Eg wait for the clock to change from idle state, read the data line and store the bit, wait for clock change back to idle state,wait for the clock to change from idle state, read the data bit and store it.......................keep going until you have the data you need.

See the manual http://melabs.com/resources/pbpmanual/5_65-5_70.htm and the clock and date illustration

[tumbleweed]

The DAC 7611 gets the clock from the excisting hardware

Do you know what the clock speed of the existing circuit is?

It could be running WAY too fast to try and catch the transaction by polling the lines.

[pyrogeek]

hardware MSSP

[tumbleweed]

It might be very difficult to capture the 12-bit DAC transfer with an 8-bit MSSP module.

[pyrogeek]

really?