callback function function

[Kevin0010]

Hey, I am building a wheeled driven robot and use WIFI extension to communicate with my laptop, in my callback function I write the velocity of two wheels into files, when USB was use for communication, this callback function works well but when I change it to WIFI extension this program seems didnot get into the callback function at all and there was nothing written in files.

Dose anybody know the reason?

[photron]

This should just work. WIFI and USB should not make a difference like this,

 

Which callback is this?

 

How do you power the stack when you use the WIFI Extension?

[Kevin0010]

Thx, The attachment is my callback function configuration and I used Step Down Power Supply to power my stack when WIFI extension was used.

[photron]

What's the SamplingPeriod?

 

One different between WIFI and USB is the throughput. Typically, WIFI has less throughput than USB. If your SamplingPeriod is very small then the Bricklets might try to send more callbacks then the WIFI connection can handle.

 

I assume you don't have USB connected to the stack while you're using WIFI, is this correct?

[Kevin0010]

The sampling period is 5ms, is it tio small? and much information will be lost by wifi? I donnotknow how to handle it, so I am still using USB now.

[remotecontrol]

Make a "ping" to your stack connected via WIFI: you might get something below 10ms, but on average I would not rely on this.

 

My experience is that I can transport about 50 data packages per second via WIFI (which makes 20ms per package) and that other WIFI networks in the surroundings have a big impact on the performance.

[Kevin0010]

Thanks! My sampling period is a problem but I tried 50ms before, it didinot work. I will  focus on this and try to find the limit of sampling period.