DAC that does not have a serial connection?

[treez]

Hello,
We wish to use a DAC but do not wish to communicate numbers to it via serial protocol.......we just want to 'bit bash' the numbers into it, -are there any DAC IC's that operate like this?

 

[ads-ee]

They are called parallel input DACs like this:

 

[treez]

Thanks but it needs too many pins.....surely there must be some DAC into which you can clock a digital value,by pulsing a "send" pin to say you are sending, then send a bit, then pulse send again to say you are sending the next bit, and then at the end of all that, say "bit sent" with another pulse to a pin........"bit bashing"...surely there are chips out there that go like that?

 

[ads-ee]

Yeah they are serial DACs...which you don't want to use?

You can bit bang a serial DAC with whatever protocol it wants, why is that a problem?

 

[treez]

the datasheets don't explain the protocol...they expect you to just hook up a serial port module of a micro and just let it all happen

 

[Dan Mills]

Every SPI DAC I have ever seen has a timing diagram somewhere in the datasheet, these are usually very simple devices (Clock, Data and a chip select).
The I2C parts are a little more complex to bit bang but you save a pin.

Regards, Dan.

 

[horace1]

if you look at device documentation you will often find sample code, e.g. Microchip's MCP4922 12bit DAC with an SPI interface
https://www.microchip.com/wwwproducts/Devices.aspx?product=MCP4922

even if the code is not for the microcontroller to be used as the host it can be useful as a guide to setting up control registers and loading data registers etc

 

[FvM]

As already mentioned, "bit bash" is obviously a serial connection and follows a protocol. In so far the thread title is completely misleading.

The minimal requirements for a "bit bashing" interface are a data line, a clock line (telling when the next should be read) and a sync line (marking either the first or the last bit). A basic SPI interface has just these three interface lines.

 

[KlausST]

Hi,

the datasheets don't explain the protocol...

What DAC and datasheet are you talking about? Manufacturer name and device name.


Klaus