i am just new to this hardware-software thing... i really have no idea on how to make a hardware work thru a visual basic program... can anybody give me an overview on this? or can anybody give me websites on this?
i also heard of SDK... what does this actually mean? how does this work?
anybody?
thanks in advance... =)
I learnt to plant my own garden instead of
waiting for someone to bring me flowers visit my blog...
If it's serial port, then you'll need to use the Microsoft Comm Control in your project.
Do a search on the forum for the MSComm control. You'll be sure to find a few examples.
GSM devices? I remember doing interesting things with SonyEricsson phones. The one thing I can distinctly remember was that the phones connected with USB will create a COM interface with a seperate COM port on your machine... If you'd like I can go scratch the old code out and post it here somewhere.
You'll probably need to use the MSComm control then.
It's actually quite simple. It uses a Protocol called RS232 which defines the characteristics of the Hardware in terms of the voltages on the pins and the way the plugs / sockets are wired up (of little interest to the Programmer normally). A hardware Handshaking methodology is also included in the RS232 Protocol which I wont go into here, but if you're interested a Google search looking for "RS232 Protocol" will return umpteen hits that will go into the detail.
RS232 also defines how data is sent and received in terms of bits and is quite flexible. As we all know a byte is (normally, these days) a collection of 7 or 8 bits. When using RS232 there are additional bits tacked on the front and end of a byte when it is transmitted.
At the front is a Start Bit, which, as the name implies, is used by the receiver Hardware to identify when a byte is being received.
Following the Start Bit is the Byte itself which can be 7 or 8 bits long.
After that comes the Parity Bit, this is for simple error reporting. There are 3 types of parity "Even" , "Odd" and "None" and you tell the hardware which type to use. Even Parity means that the Parity Bit will be set to a 1 if the number of bits in the byte having a value of 1 is even. Odd Parity is similar except the Parity Bit is set to 1 if the number of 1 bits is odd. "None" is as it implies, no Parity checking is performed. The hardware keeps count of the 1 bits and will raise a Parity Error, which your program can trap, if it's incorrect.
Finally, after the Parity Bit comes one or two Stop Bits which tells the hardware that all the bits should have been received.
Also, the serial interface can work at a number of different (set) speeds.
Using the MSComm control it's very easy to tell the Hardware how to configure itself. eg
Code:
MSComm1.Settings = "9600,N,8,1"
This configures the serial port to:
Speed = 9600 bits per second
Parity = "N" = None (ie ignore parity)
Number of data bits = 8
Number of Stop bits = 1
Of course, your Port configuration must be the same as the device you're connecting to. For example, if the device you're connecting to can only operate at a maximum of 4800 bits per second then you have to adjust your speed to match. Once you've configured the port you can get down to the interesting stuff like programming.
GSM devices? I remember doing interesting things with SonyEricsson phones. The one thing I can distinctly remember was that the phones connected with USB will create a COM interface with a seperate COM port on your machine... If you'd like I can go scratch the old code out and post it here somewhere.
that would be great! please do.. thanks a lot billgeek... =)
I learnt to plant my own garden instead of
waiting for someone to bring me flowers visit my blog...
You'll probably have to change the MSComm Port Number if you are going to run it.
It's currently set to 4 in the Form_Load event, most likely you'll need to set it to 1 or maybe 2 depending upon how many Serial Ports you've got and which one the 'phone is connecting to.
GSM devices? I remember doing interesting things with SonyEricsson phones. The one thing I can distinctly remember was that the phones connected with USB will create a COM interface with a seperate COM port on your machine... If you'd like I can go scratch the old code out and post it here somewhere.
can i have your sample code billgeek?
I learnt to plant my own garden instead of
waiting for someone to bring me flowers visit my blog...
I seem to have misplaced it somewhere. I'm busy working on a bit of code that I will attach here when I'm done. (It's not working at the moment, so I'm trying to check why)
May I suggest that you try to get hold of the whitepapers for the devices that you wish to use. I had to download the Sony Ericsson whitepapers in order to find out what the AT codes were to communicate to it, and it helped me quite a bit.
You'll probably have to change the MSComm Port Number if you are going to run it.
It's currently set to 4 in the Form_Load event, most likely you'll need to set it to 1 or maybe 2 depending upon how many Serial Ports you've got and which one the 'phone is connecting to.
Anything I post is an example only and is not intended to be the only solution, the total solution nor the final solution to your request nor do I claim that it is. If you find it useful then it is entirely up to you to make whatever changes necessary you feel are adequate for your purposes.
connecting hardware to software?
Originally Posted by BillGeek
Re: connecting hardware to software?
