I am working on a PC program to control a Nokia 6682 phone which is connected to my PC machine.
The program can send "key press" instruction to phone, and can receive phone LCD images to display
For the connectivity between PC machine and Nokia phone, I chose to use PC Suite Connectivity API (v1.1),
because it hides all low level device driver and comm protocols. PC Suite ConnAPI (v1.1) uses file based
data transfer, instead of stream based (such socket). So my PC program produce a "key press" instruction file,
put the file into phone, and my phone program picks up the "key press" file and perform the actual key press.
Another phone program takes LCD image and saves it to a file on the phone, and my PC program checks if there is
a LCD image file on the phone, if so, it takes the file from phone to PC machine, and then displays the image on PC.
So functionally, it is working fine. But the issue is about the performance - I can see about up to one second of
LCD image delay, and about one second of key press delay.
I narrow down the bottleneck is within PC Suite Connectivity API which transfers files between device and PC.
For one LCD image of Nokia 6682, it has 72k of file size (with 16 bit color). The best PC Suite ConnAPI can do is about
4 frame per second (the underlying connection is via USB cable, the Bluetooth will be much slower).
Also it seems the data tranfer is in half-duplex mode, my small "key press" file has to wait to be transferred
from PC to phone, until the large image file has been download from phone to PC.
I would like to improve the performance at least several times better, with no human noticable delays of key press command and LCD image.
My question about PC Suite ConnAPI:
1. Is there any way to make PC Suite Connectivity to use stream based, instead of file based? So that I can send key press command string
directly to my phone program to cut down the time of checking file system for the command file.
2. Prior to PC Suite Connectivity API, how people would establish and programtically control the local connectivity between
PC and Phone using USB cable? I am aware of using virtual serial comm over bluetooth, but that approach leads to about one second of delay too.
3. Someone mentioned that Nokia Forum PRO version of ConnAPI has more functionalities - anything related to data transfer rate?
or help me to improve the data transfer between PC and phone?