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victorf
Joined: 01 Jan 2006
Posts: 342
Location: Schenectady, New York
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Posted: 01 May 2006, 17:55 PM Post subject: |
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zbasicandy,
Do you have any experience with the EDE1144 that you would care to share with us 
Vic |
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zbasicandy
Joined: 26 Jan 2006
Posts: 193
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Posted: 01 May 2006, 18:59 PM Post subject: Keyboard encoder |
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EDE1144 Looks like a pre-programmed micochip with a sticker on it.
My neighbor uses it in his ham/repeater/junk equipment.
If you look at the specs they are very simple...
All the overhead is taken care by the PIC.
From the manual
SERIAL DATA CONNECTION
To receive keypress data serially from the EDE1144, two options exist. The first (typically used with a host microcontroller having an onboard hardware UART) is to simply connect the XMIT (Pin 1) line to the host microcontroller's serial data input. Each time a key is pressed (or the
autorepeat loop cycles) one byte will be transmitted, corresponding to the values shown in Table One. The host microcontroller's hardware UART's 'Receive Buffer Full' flag can be polled to monitor for newly received serial data; alternately the host microcontroller can be configured to generate an interrupt when a new byte is received by the UART.
RS-232 OUTPUT
The RS-232 Output (Pin 1) transmits serial data to the host microcontroller. This data is sent at either 2400 or 9600 Baud, as selected by Pin 2. Data is send in traditional N-8-1 (no parity, 8data bits, one stop bit) format at TTL/CMOS voltage levels; i.e. 0V to 5V. This serial output
signal can be connected directly to the host microcontroller's serial input pin without any type of voltage level conversion. However, if data is to be sent to a device expecting RS-232 voltage levels of -12V to +12V (such as a PC), a voltage level conversion IC such as the MAX232 will be needed between the EDE1144's serial output pin and the PC's serial input pin.
Hint:
Do not read the data from your queue into a string!
Like I said, "if you can't make this simple serial keypad encoder work then
I will produce the code for you - for FREE"
What is your specific question? |
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victorf
Joined: 01 Jan 2006
Posts: 342
Location: Schenectady, New York
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Posted: 02 May 2006, 10:05 AM Post subject: |
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zbasicandy wrote:
| Quote: |
Hint:
Do not read the data from your queue into a string!
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Why
Vic |
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zbasicandy
Joined: 26 Jan 2006
Posts: 193
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Posted: 02 May 2006, 11:27 AM Post subject: |
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I was referring to the he link "ZBasic's software UART insight"
Don's
| Quote: | | I suspected that you might be doing that. You can't pass a reference to a string to the queue retrieval functions. The retrieval functions simply begin writing the retrieved data beginning at the first byte of the address that they receive. They don't know (can't know) that the first two bytes should be skipped because they contain control information for the string. Moreover, they don't know that the length control byte might need to be updated. |
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dkinzer
Site Admin
Joined: 03 Sep 2005
Posts: 2593
Location: Portland, OR
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Posted: 02 May 2006, 15:35 PM Post subject: |
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| Quote: | | Do not read the data from your queue into a string! |
More precisely, do not pass a string variable to the GetQueue() routine. This caveat is explicitly noted in the documentation for GetQueue along with an explanation of how to get characters from a queue into a string.
The next release of the compiler and VM will support a new System Library routine GetQueueStr() that returns a string containing characters extracted from a queue. The new versions are in final test now. |
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zbasicandy
Joined: 26 Jan 2006
Posts: 193
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Posted: 02 May 2006, 16:20 PM Post subject: new string function |
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| Quote: | | The next release of the compiler and VM will support a new System Library routine GetQueueStr() that returns a string containing characters extracted from a queue. The new versions are in final test now. |
Below is my "workhorse" of all my serial "input" communication routines.
Will your new string function reduce this code?
| Code: | '===============================================
public Sub Get_String_40(Byval port as byte, Byref Rx_str as string, Byref Num_char as integer, _
ByRef TimeOuts as single, Byref Success as boolean)
'
'This routine will retreive up to 40 chars from the input buffer.
'(Note in/out buffers are set at 41) (50 - 9 = 41)
'It has an adjustable timeout parameter (TimeOutS in (single) seconds)
' and a Timeout "flag" -> (True = Timeout) and (False is no Timeout)
' Return Success = no timeout!
'====================================
' Revision 1.0b 4/5/06 by Don Kinzer
'====================================
'Number of chars (Num_Char) has to be < = 40 chars!
Dim RxBuf(1 to 40) as Byte
Dim Timeout as boolean
Timeout = Not Success ' make (default) timeout true for sub GetQueue
CALL GetQueue(CByteArray(Inbuf(1, port ).DataAddress), RxBuf,Num_Char,TimeOutS,Timeout)
Rx_str = MakeString(RxBuf.DataAddress, Num_Char)
If (Timeout) then 'GetQueue char "timeout" due to not enough time e.g. TimeOutS
Success = False
Else
Success = True
End if
End Sub
'=============================================== |
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dkinzer
Site Admin
Joined: 03 Sep 2005
Posts: 2593
Location: Portland, OR
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Posted: 02 May 2006, 18:47 PM Post subject: |
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| Quote: | | Will your new string function reduce this code? |
In this case, no. The GetQueueStr() function doesn't have the timeout feature that the more general GetQueue() has. It is intended to be used where either you know that the desired number of characters exists in the queue or you just want to retrieve whatever characters happen to be in the queue. For those use cases, you can avoid having to fetch characters into the temporary buffer and then construct a string with them.
The code below is a modified version of your code (untested) that includes protection against overflowing the temporary buffer. It also returns an empty string when a timeout occurs. This may allow you to eliminate the 'Success' parameter since the string length will indicate success/failure.
| Code: | Public Sub Get_String_40(ByVal port as byte, ByRef Rx_str as String, Byref Num_char as Integer, _
ByRef TimeOuts as Single, ByRef Success as Boolean)
Dim RxBuf(1 to 40) as Byte
Dim Timeout as Boolean
' limit the number of characters to be retrieved
Num_char = Min(Num_char, SizeOf(RxBuf))
' retrieve the requested number of characters, subject to timeout
CALL GetQueue(CByteArray(Inbuf(1, port).DataAddress), RxBuf, Num_char, TimeOutS, Timeout)
' create a string containing the retrieved characters, if any
If TimeOut Then
Num_char = 0
End If
Rx_str = MakeString(RxBuf.DataAddress, Num_char)
' indicate success/failure
Success = Not TimeOut
End Sub |
Last edited by dkinzer on 02 May 2006, 22:30 PM; edited 2 times in total |
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zbasicandy
Joined: 26 Jan 2006
Posts: 193
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Posted: 02 May 2006, 19:41 PM Post subject: |
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| Quote: | | The code below is a modified version of your code (untested) that includes protection against overflowing the temporary buffer. It also returns an empty string when a timeout occurs. This may allow you to eliminate the 'Success' parameter since the string length will indicate success/failure. |
Point taken on this "patch" for my string return subroutine. 
Having both the success and empty string will allow greater flexibility in my comm/response routines. |
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