To pick up this thread some Andrew, I’m currently running into something that may or may not be an issue.
For example, if I set GPIOs like this:
int gpiosteps = 2;
SmGPIOStep Steps[gpiosteps];
Steps[0].freq = 2.40e9;
Steps[0].mask = 0x00;
Steps[1].freq = 2.47e9;
Steps[1].mask = 0x0F;
and look at it on the O-Scope, I get the exact same pulse as if I set something like this:
int gpiosteps = 2;
SmGPIOStep Steps[gpiosteps];
Steps[0].freq = 2.40e9;
Steps[0].mask = 0x00;
Steps[1].freq = 2.49e9;
Steps[1].mask = 0x0F;
With the frequency of the second step 20MHz further down the line.
So, my concern is when the GPIO goes low, what frequency is it actually going low at? Is it 2.4GHz, or that plus/minus 40MHz? 60MHz? 160MHz?
Like I said, I’m triggering external test equipment, and in this example Step2, when the GPIO goes high, it causes an interrupt in our microcontroller that goes and sets up the next piece of equipment. We’ve gotten the timing such that that setup is done and complete before the GPIO waveform goes low, but not by much.
But we know that it going low isn’t happening *exactly* at 2.4GHz, and so we might be making our timing…or we might not.
So, I understand that figuring out where those GPIO transitions ARE happening is tough; but I really do need to know. I can do complex things, or if it’s just a one-off where you can just tell me where it’s happening based upon my sweep parameters, that’d be great. If I need to write 500 lines of code to figure it out, great also. If I request certain frequencies, and the SM200A comes back to me with what it’s actually going to do, that would work also. But I do need to know…
This is literally our last hurdle to fielding this capability, and I’d really like to get it figured out, shipped and move onto our next fun project 🙂
Thanks!
