Arduino serial port really slow

Core Library Questions

Kobby

Arduino serial port really slow

in Core Library Questions • 1 year ago

Hey all, I'm working on some basic sketches with processing communication with arduino for a workshop class and I'm running into a weird issue. The serial library connection is VERY VERY SLOOOOOOOOOOWWW. I'm not sure whats going on but there is a huge lag between processing and the arduino over the serial library. I thought it was my code so i took everything out except for reading and writing (println commands, conditionals, etc) and it was still running very slow.

I tried using the SimpleWrite example that comes with the processing libraries and that was super slow as well. I'm not sure whats going on.

I switched the Arduino library which uses the same serial library and everything seems to be running fine again.

I used the serial library with arduino and processing for my senior project from college 3 months ago in december and it worked fine. The only difference in my setups is that I am running Mac OSX 10.7 (lion) now as opposed to snow leopard 10.6 back then. Can anyone shed any light on why this is being so slow? If you need a code sample to test with, just use the processing example 'SimpleWrite' because thats what I was using.

Replies(3)

Ben Purdy

Re: Arduino serial port really slow

1 year ago

I'm having this same problem.. I'm running lion and I'm trying to send about 190 bytes per frame from my sketch (running at only 15 fps) but when I do the serial communication my sketch grinds down to about 5 fps.

The sketch crashes on exit as well, with the error "Invalid memory access of location 0xbbb04b70 eip=0x8fbd490c" even though I'm closing the port in the "stop" method.

Anybody else run into this? Any solutions?

tomschofi..

Re: Arduino serial port really slow

1 year ago

same problem here, also running OSX lion, did anyone get a solution?

Kobby

Re: Arduino serial port really slow

1 year ago

sorry i didn't see this earlier. Honestly, I'm not sure how it was fixed, it just stopped being a problem for me. A few things to look into :

make sure there are no differences in the serial jar files and the native library files. When you run the sketch there will be a message in the console that compares the versions you and will let you know if there is a mismatch.

try to remove all print commands that go into the arduino monitor, those can be expensive.

make sure there is no damage to your usb cable, try testing with an arduino on a snow leopard or something to make sure its not a buggy cable.

if none of this works, install the Standard Firmata from the arduino examples onto your board and try using the Arduino Processing library which manages the serial connection within itself.

Hope this helps.

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