USBDemo, something to learn USB a little bit

[Josuetas]

Hi.

To Mister_E or anyone that really understand this (i clearly don´t). I made this post already but none seemed to understand it, so i am posting again in other words.

I made this software that controls an USB device, it all began with Mister_E`s demo, it is working really fine now, no problems with it. NOW i want to use two devices, same software!. Lets say this is a temperature sensor, now i want to measure two diferent points so i wan´t to connect two diferent sensors. HOW can i differentiate both devices? when i connect the second one the first connected gets useless (I am sure the handler is replaced).

I´ve been reading the whole code for Visual Basic and PBP, i don´t intend to change my device ID and Product ID.. this would be useless. Does the Driver easyHID only works with one device?

Please give me a little advice on this matter.. How can i use two different handlers?

Thanks

DJC

[mister_e]

2 different ways
1) assign, then read the device serial number -> this has to work
2) use a specific data byte in DataToSend as identifier -> not 100% sure of it

[Josuetas]

Hi.. thanks for your reply Mister_E.

I have this problem with both solutions!... i dont have two working devices when i connect them... i just have one! When i connect the second one the first connected doesn´t work!
My guess is that this happens because the handler of the first connected device is lost and replaced for the second one.. hence my sent data (from pc to device) is just received in one of the ports (this is for sure!) so it wouldn´t work to use the serial number because i can´t even get it :s.

The same reason for the second choice.

I also think that both devices could have exactly the same software, my guess is that this is a matter of software (in VB), there should be a way to create two different connections (what i call handlers) but i don´t get where this is done in the code Sub ConnectHID().

Again maybe i am thinking this wrong but this is what you would do with two diferent serial devices in different serial ports, you would have two different interrupt routines in the VB software to control each one.

I really hope someone could guide me here, has none connected two devices?

Thanks again for your time and concern,

DJC

[mister_e]

i already done that... i just need to find out where... i had to do some unwanted Hard-Disk clean-up recently... i hope i still have it somewhere, unless i may try to redo it once again.

[Josuetas]

Hi!

I was hoping somenone could give any ideas on my subject, its been more than a week and no post here, You don´t have to know the solutions... lets just talk about your oppinions or ideas

Thanks for any help

[mister_e]

i already gave mine, maybe yu could check on wich hub/port a specific device is connected... i just don't have any spare time... but i could deal with few K-CAN$

[Darrel Taylor]

I can't speak for Visual Basic, but in Delphi, you request a list of HID devices, and each one has it's own "Handle".

If two devices have the same Vendor/Product ID's then you look for the serial number to tell the difference. But access to the device is by specifying the Handle.

Here's a small program that can identify the serial number and handle. Note: the handle changes on every connection or power-up/re-boot.

www.pbpgroup.com/files/HIDmonitor.exe
Put it anywhere, there is no installation to do.
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