Flowcode Support Board

Hi

I am using a dsPIC ECIO and 2 EB085 A/D boards

I understand how to read these channels in normally using your component but i wish to synchronise the A/D inputs ie read both at same time point

I require to sample at around 20k not too fast for the chips (100k) so i am sure it can be done

Any ideas

David

Hi David,

I've not tested this on hardware but this should hopefully do what you need, or at least show you the way.

Hi Ben

That's great

Understand your logic and will try out on the hardware later this week


Many thanks
David

Hi Ben

I tried your idea today

Does not appear to work (Note i am injecting 1khz into the EB805 card)

However if i disable your loop and enable the normal EB085 component i get the 1Kz tone out of the EB086 so the rest of the setup appears to be working okay

Note i am currently only using 1 EB085 for test purposes so i have // the 2nd EB085 in the c code

Any further ideas

David

Hi David,

I got the upper and lower bytes reversed, Please can you try this instead and hopefully it will work better.

Ben

Great now works fine on the single EB085 configuration i tested

Will try with 2 EB085's configuration next week

Many thanks for fast response

Excellent service as usual

David

Ben

Tried the second A/D converter in hardware that works fine in synchronising and i can output each to the EB086 output as required

However when i try to add the 2 waveforms together using the DSP Math + funcion i have a problem

It only appears to see input on the A channel

It does not appear to see any input i put into the B channel

Can you check the math + function

I do note that in the simulation mode it does appear to see both A & B inputs if i use the sinewave generator to test it

Any ideas

David

Hi David,

I can't see anything incorrect in the code generation of the math function. It seems to be working correctly.

I wonder if there is a gain problem or something similar on the channel B input hardware?

The generated code looks like this.

DSPBuff_6_Put(FCV_05d31_DSP_Math1__INDEXOUT, DSP_Math1_Ref1_Get(FCV_05d31_DSP_Math1__INDEXA) + DSP_Math1_Ref2_Get(FCV_05d31_DSP_Math1__INDEXB));

which boils down to

MathBuffer[0] = DSPInput1[0] + DSPInput2[0];

Ben

I had already tried that ie I fed the same channel to A & B seperately and even the same channel to both A & B at the same time and in all cases the input on the B channel had no affect on the output ?

David

Hi David,

Many thanks for chasing this one, I've replicated the problem and beleive I have now spotted the issue and am in the process of a fix. Hopefully I'll have one for you shortly. I beleive it's a case of a semi colon in the wrong place ending the command too early before the B input gets added.