HDQ protocol

[Jam78]

Has anyone worked with HDQ protocol?, I have a microcontroler that uses this interface which is a one-wire communication device, I have been trying with a USB-8451 but no joy.

Any help is appreciated? Thanks!

[Scott_G]

Hi Jam78,

I am sorry but unfortunately National Instruments does not have any hardware that officially supports the HDQ protocol.  If you would like to request that we develop that hardware, you can visit

www.ni.com/contact and click on the feedback link in the lower left corner of the screen.  This feedback is taken very seriously by our marketing team and R&D. 

Thanks!

[Jam78 · Accepted solution]

Thanks for your Reply, Let me explain a little more, if you look at the file I attached you can see what I'm trying to do, HDQ protocol is a one-wire communication that send and receives 1 byte at a time, on every transaction you need to send a break of >200µs then you send a memory address byte and then you read or you write a byte, the line that is being used to communicate should be high in its idle state, to evaluate if the bit is a one or a zero you need to measure the time that it is low, for example if the line is low for 30-55µs then it's a 1 and if the line is low for 150-155µs then it's 0. That is it!

 
Now I was able to create this signal unit waits and a DIO on a NI-6023E but I could only do it in milliseconds and I need microseconds.

I have been trying to somehow do this with the clocks and counters in the 6023E board but no joy yet. Speaking of counter their was to be a way I can pull a line low while a timer cycles for a finite number of times and bring that line back up right after the timer finishes, I heard of something called Timer TC, but I cannot get it to work.

Thanks for you help!!

[mikeporter]

A high-speed digital IO can also do this. I had a job once where we had systems that had to interface directly with the UUT using a proprietary serial data stream. We simply created digital patterns that we stored in the board's memory. We then transfered the waveform out two channels (data and a sync clock). We even had high-speed serial input using a digital input channel.

Mike...