4 replies to this topic

[xmen]

I have a I2C LCD that needs to be updated rapidly, the problem is that. If I write in LCD from a separate Thread it is very slow, but if I write from main thread. Its like 10 times faster. I even set the Thread.Priority to Highest but it doesn't effect anything. And if I start a thread with Highest priority and write from main thread. Main thread is more slower(I think its priory is normal)

 

What I know about threading is that each thread gets 20ms time slice on each iteration. So if I2C is writing in 40ms, that means it has to wait 20ms x n threads to complete its write. Thats why it is slow ? Seems to me that I should avoid Threads if I need speed.

 

 

Am I missing something ?

[Chris Walker]

Hi xmen,

Try to keep threads asleep unless they are actively doing something.

Do you have any "spinning loops" occupying 100% of MCU?

Chris

[xmen]

Hi xmen,

Try to keep threads asleep unless they are actively doing something.

Do you have any "spinning loops" occupying 100% of MCU?

Chris

Hi Chris,

 

I did try with Thread.Sleep(1000) in main thread loop. Didn't get any difference.

[Chris Walker]

Hi xmen,

Do you only have two threads running (main, sleeping...and the I2C thread)?

In theory both threads should have the same priority.

In the end...do what works well. But if you're seeing strange behavior and we can reproduce it consistently, let's pull Microsoft into the conversation for a potential NETMF vNext performance boost.

Chris

[xmen]

Hi xmen,

Do you only have two threads running (main, sleeping...and the I2C thread)?

In theory both threads should have the same priority.

In the end...do what works well. But if you're seeing strange behavior and we can reproduce it consistently, let's pull Microsoft into the conversation for a potential NETMF vNext performance boost.

Chris

Hi Chris,

 

I just realized and remember that main thread has inner hidden loop(in another class) which I was unaware of. And the main thread was never actually sleeping. Anyways, I now use Single Threaded app, works better. And I try to avoid Thread.Sleep at all cost.