EasyHID and USB for Newbies??

[rocky79]

Using easyhid is not that bad.

Basic steps are run up the easyhid program and set the basics like Pid/Vid and buffer size for bytes you want to send back and forth from PC to Pic.

It then by default creates two folders under a top level folder called USBProject

The first folder is PICBasicPRO

This contains the basic code you will need for your pic chip and the include files, do not rename or move this directory once it is created, work from this location.
It will create a example PBP file called USBProject.pbp

So open this up and the main program loop you are interested in is:


'****************************************
usbinit ' initialise USB...

ProgramStart:

gosub DoUSBIn
gosub DoUSBOut

goto ProgramStart
'*****************************************

For receving and sending data you just need these two routines.

If you wanted to receive say 10 bytes then it does matter that your buffer is set to 64 bytes because that is the packet size that is going to be received from the PC anyway, so do not worry about this. Just tell it to jump off to that routine and as soon as data is received it will come back from that routine with the usbbuffer(0) to usbbuffer(63) filled as such.
So if your PC sent 10 bytes then the variables usbbuffer(0-9) will hold those 10 bytes, if your pc sent 20 bytes then usbbuffer(0-19) will hold those bytes.

So say you wanted to send 4bytes from your PC to the Pic and then the Pic displays it on the LCD, you could do this:

'*******************************************
usbinit ' initialise USB...
ProgramStart:

gosub DoUSBIn

LCDOUT $FE,1,usbbuffer(0),usbbuffer(1),usbbuffer(2),usbbu ffer(3)

goto ProgramStart
'*******************************************

If you then wanted to send say two bytes back to the PC to say you received them, then just load up your usbbuffer variables and jump to the routine gosub DoUSBOut.

So to send "OK" back to the PC add this to your code.

'*******************************************
usbinit ' initialise USB...
ProgramStart:

gosub DoUSBIn

LCDOUT $FE,1,usbbuffer(0),usbbuffer(1),usbbuffer(2),usbbu ffer(3)

usbbuffer(0)=79 'Ascii value for O
usbbuffer(1)=75 'Ascii value for K
gosub DoUSBOut

goto ProgramStart
'*******************************************

And thats ya simple pic code to receive and send bytes back and forth. Now you know how to get your bytes in and out, you can use them just like any other variables.

The Second Folder it creates is dependent on what you are developing in, I play with Visual Basic so it created me a Folder called VisualBasic and inside here is sample code and the files you will need, I aslo copy the file mcHID.dll from C:\Program Files\Mecanique\EasyHID\ into this folder as well to play safe.

So again for the VB side of things to send data out to the Pic via the USB Port you simply load up the Bufferout(1-64) you always send Bufferout(0)=0 as a header.

So to send 4 bytes from Visual Basic just use the following:

'*******************************************

BufferOut(0) = 0
BufferOut(1) = 68 'Ascii Value for D
BufferOut(2) = 65 'Ascii Value for A
BufferOut(3) = 84 'Ascii Value for T
BufferOut(4) = 65 'Ascii Value for A
hidWriteEx VendorID, ProductID, BufferOut(0)

'*******************************************

To receive Data in VB, the sample code basically sits there and waits for a recieve event to happen and when it does, it jumps off to a routine called OnRead and populates the variables BufferIn(1-64).

So you could do a simple loop to keep checking the value of BufferIn(1) and BufferIn(2) until they receive the "OK\2 back.
To see it in action set up a object called Text1.Text on your VB Form and then in your code add the following:
'*******************************************

Text1.Text = Chr(Val(BufferIn(1)))
Text1.Text = Text9.Text & Chr(Val(BufferIn(2)))

'*******************************************

Hope this helps.

Regards Sean.

Hi Sean,

If i want to write a byte to the microncontroller can i say BufferOut(2)=%10011111 (" for example)
In your code above:
BufferOut(1) = 68 'Ascii Value for D
BufferOut(2) = 65 'Ascii Value for A
BufferOut(3) = 84 'Ascii Value for T
BufferOut(4) = 65 'Ascii Value for A
hidWriteEx VendorID, ProductID, BufferOut(0)
and to send the info,
are you sending BufferOut(2), BufferOut(3)....and so on?
if i wanna send the values in bufferout(2) would the code look like this below?
hidWriteEx(VendorID, ProductID, BufferOut(0),BufferOut(2) )


Thanks much

[sean-h]

Hi rocky

When you call hidWriteEx(VendorID, ProductID, BufferOut(0)), what you are doing is sending a packet as such out to the USB port.
So you can define the length of that buffer in your VB vode at the top of the code:
Private Const BufferInSize = 64
Private Const BufferOutSize = 64

and in your PBP code:

USBBufferSizeMax con 64 ' maximum buffer size
USBBufferSizeTX con 64 ' input
USBBufferSizeRX con 64 ' output

I think min is 8 bytes and max 64.

So just change these variables to cut down the amount of bytes you want to send.

BufferOut(0) is a report ID and data starts at BufferOut(1)

Regards

Sean.

Hi Sean,

If i want to write a byte to the microncontroller can i say BufferOut(2)=%10011111 (" for example)
In your code above:
BufferOut(1) = 68 'Ascii Value for D
BufferOut(2) = 65 'Ascii Value for A
BufferOut(3) = 84 'Ascii Value for T
BufferOut(4) = 65 'Ascii Value for A
hidWriteEx VendorID, ProductID, BufferOut(0)
and to send the info,
are you sending BufferOut(2), BufferOut(3)....and so on?
if i wanna send the values in bufferout(2) would the code look like this below?
hidWriteEx(VendorID, ProductID, BufferOut(0),BufferOut(2) )


Thanks much

[rocky79]

Thanks Sean for the explanation, but there is still something i don't understand.
Question#1:
On the microcontroller side: How can i send the results of a 12 bits A2d Signal from the microcontroller to visual basic.net since USBBufferout is defined as a byte.
Question#2
on the Visual basic.net side when your ready to send data back to the controller:
do you just include all the 64 bufferout bufferout(1) bufferout(2)....bufferout(63)
HidWriteEx, VendorId, ProductID, BufferOut(0), BufferOut(1)....BufferOut(63)
Or is there a shorter way to do it.

Thanks Sean

[rocky79]

Question#2:
On the visual studio.net side: In this code below that i got from EasyHid how do you fill in where it says: put your code here?
I would appreciate Any examples:

Public Sub OnPlugged(ByVal pHandle As Integer)
If hidGetVendorID(pHandle) = VendorID And hidGetProductID(pHandle) = ProductID Then
' ** YOUR CODE HERE **
End If
End Sub

'************************************************* ****************
' a HID device has been unplugged...
'************************************************* ****************
Public Sub OnUnplugged(ByVal pHandle As Integer)
If hidGetVendorID(pHandle) = VendorID And hidGetProductID(pHandle) = ProductID Then
' ** YOUR CODE HERE **
End If
End Sub

'************************************************* ****************
' controller changed notification - called
' after ALL HID devices are plugged or unplugged
'************************************************* ****************
Public Sub OnChanged()
Dim DeviceHandle As Integer

' get the handle of the device we are interested in, then set
' its read notify flag to true - this ensures you get a read
' notification message when there is some data to read...
DeviceHandle = hidGetHandle(VendorID, ProductID)
hidSetReadNotify(DeviceHandle, True)
End Sub

'************************************************* ****************
' on read event...
'************************************************* ****************
Public Sub OnRead(ByVal pHandle As Integer)

' read the data (don't forget, pass the whole array)...
If hidRead(pHandle, BufferIn(0)) Then
' ** YOUR CODE HERE **
' first byte is the report ID, e.g. BufferIn(0)
' the other bytes are the data from the microcontrolller...
End If
End Sub

'************************************************* ****************
' this is how you write some data...
'************************************************* ****************
Public Sub WriteSomeData()
BufferOut(0) = 0 ' first byte is always the report ID
BufferOut(1) = 10 ' first data item, etc etc

' write the data (don't forget, pass the whole array)...
hidWriteEx(VendorID, ProductID, BufferOut(0))
End Sub
End Class

[sean-h]

Hi Rocky

I got compile errors in VB2005 so sticking with VB6, does it compile okay with ,net your end?

The two main routines to worry about and get you going are receive and transmit Data Routines.

Please scroll up on this post as I have given some VB examples already on what you have just asked.

Regards

Sean.

[rocky79]

sean,
Sorry for the late reply, my computer crashed so i was crippled for the past week. I will try your code as soon as i get things back in place.
thank you much

[scorpion]

Hi
I was wondering what I might be doing wrong...
I used HIDMaker to make an input device. Im using the standard HID descriptors, so I am not writting any PC side software.
Everything is working well, but I have two analog inputs. They are both set to words so i can use the 10bit a/d. but when I look at the input on the computer its only 8 bit. and if i right justify the results i am only getting a change of 3.... which is what i would expect if it was only sending 8 bits.

hrm........
if i do some math (invert one input) i can offset the output to 10 bits, so is my a/d conversion 8 bits?

I have used 10 bit inputs on other projects with other pics and I have never ran into this problem before.

I have everything set up.

DEFINE adc_bits 10
TRISA = 255
TRISB = 255
ADCON0 = 0
ADCON1 = %00001101

does anyone have any idea what im doing wrong?

[luisfe]

Hello. I'm making a program who include easyhid for the 18f4550 but I have some questions:
I want to pass 10 decimal 2 digit variables and 11 bit variables from the PIC to the PC, then something simmilar in return. Do the usb buffers support this just declaring de proper variables?
Or I need some kind of conversion or trick?
Thank you for your help.
Luis

[rocky79]

Hi Rocky

I got compile errors in VB2005 so sticking with VB6, does it compile okay with ,net your end?

The two main routines to worry about and get you going are receive and transmit Data Routines.

Please scroll up on this post as I have given some VB examples already on what you have just asked.

Regards

Sean.

Sean,
I am just wondering if you know any good graphical widgets for Visual basic 6.0. Like meters, gauges, level indicators and so forth.

Thanks

[mister_e]

http://www.picbasic.co.uk/forum/show...light=softwire

Seems to have change now.. maybe there's still some free version for VB6 somewhere

Ask them

[sean-h]

Thanks Sean for the explanation, but there is still something i don't understand.
Question#1:
On the microcontroller side: How can i send the results of a 12 bits A2d Signal from the microcontroller to visual basic.net since USBBufferout is defined as a byte.

A byte is only 8 bits so you will have to store your result in a variable defined as a Word (16bits)
Now you will need to split the word and send the highbyte and lowbyte out as two bytes.
In your VB program you will then need to take the 2 bytes and joing them back as a word.

Question#2
on the Visual basic.net side when your ready to send data back to the controller:
do you just include all the 64 bufferout bufferout(1) bufferout(2)....bufferout(63)
HidWriteEx, VendorId, ProductID, BufferOut(0), BufferOut(1)....BufferOut(63)
Or is there a shorter way to do it.

Re-read what I wrote above regards data being sent from VB. when you call HidWriteEx, VendorId, ProductID, BufferOut(0) you are telling the USB port to send all the data in the BufferOut.
So if you have defined your BufferOut as being 64 bytes long then when you call HidWriteEx it will send all 64 bytes, if you defined your BufferOut as being 8bytes long then it will send 8 bytes.

So simply load all the buffers up with the bytes you want and call HidWriteEx when you want to send.

Regards

Sean.

[Demon]

Hi rocky
...
USBBufferSizeMax con 64 ' maximum buffer size
USBBufferSizeTX con 64 ' input
USBBufferSizeRX con 64 ' output

I think min is 8 bytes and max 64.
...
Sean.

Nope, 1 to 64 bytes for both input and output buffers according to EasyHID help files under Configuration Details.

Robert

[bigbear]

Is there somewhere that I can see a list of the assembly codes for a PIC such as the 18F4550? From what I understand there are not a huge list of them. It has been a while since I did assembler, but I would like to have the ability to combine PBP and assembler.

[Demon]

You'll have better luck getting an answer to an Assembler-related question if you start a new thread in the General forum:
http://www.picbasic.co.uk/forum/forumdisplay.php?f=7

This thread is about EasyHID and interfacing via USB.

Robert

[mister_e]

Is there somewhere that I can see a list of the assembly codes for a PIC such as the 18F4550? From what I understand there are not a huge list of them. It has been a while since I did assembler, but I would like to have the ability to combine PBP and assembler.

you can mix both of them using ASM and ENDASM. You can have the asm list if you open the .COD file or the .LST file

[Demon]

Ok, I've reread this thread hoping to find a hint why the device is not recognized by windows.

I had it working using HIDMaker FS, but I'm trying to use EasyHID since the resulting code is MUCH more compact. Here's what I've done so far:

- generated code with EasyHID, 1 byte to PC, 30 bytes to PIC.
- modified generated PBP program to include an LCD, that works great.
- move MCHID.dll to VB6 working folder.
- compiled the generated VB code using VB6.
- started up the executable.
- reset the PIC and that's when the error appears in Windows.

Can the generated VB6 code work without doing any input or output? I was trying to just get a skeleton VB6 program working first, and then add 1 feature at a time.

Robert

[mister_e]

Sure the VB program can work without any in/out.

[sean-h]

Hi Rocky

Sorry forgot to answer this bit

If i want to write a byte to the microncontroller can i say BufferOut(2)=%10011111 (" for example)

In VB you will need to convert your Binary value to Decimal and then load your Bufferout(2) variable.

Here is a nice feunction example for Visual Basic

http://www.vb-helper.com/howto_decimal_to_binary.html

Regards

Sean.

[lentz]

Hi, my name is Davide. i'm start to program the pic18f4550.
This topic is very interesting!!

Usually i program pic16c765 and i use VB6 and the HIDcomm component for comunicate by USB with my pic.
Now, my question is: Have you got a simple example for turn on a led with pic18f4550 by vb6?

Thank for your time.

Regard, Davide