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Forum Index : Microcontroller and PC projects : Interrupts
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palcal Guru  Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
I'm running a program that uses an interrupt. All is OK, the interrupt runs OK, but when it gets the IRETURN it must return into the middle of A 'Do-Loop' and I get an error message 'Loop without matching Do'. Am I doing something wrong. Paul. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3167 |
Sounds like a bug to me. Can you demonstrate the fault with a short program (ie, less than 10 lines)? Geoff Graham - http://geoffg.net |
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| palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
Geoff, I wrote a snipped of code and it worked ok. What I am doing is jumping out of your GPS routine with an interrupt. If it happens to return in the first part it works ok but if it returns during the GOSUB I get the LOOP without DO. Paul "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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| palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
Something I forgot to mention. I get the error on the line of the IRETURN I would have expected to get a LOOP without DO error on the line of the LOOP. Paul. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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| palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
Geoff, The best I can do to demonstrate the problem was to modify your GPS routine to do the same as I am doing in my program. I have put in an interrupt to jump to a time display for a few seconds before it goes back to displaying the position. The error occurs in line 282 'Do Without Matching Loop' My modified code... 10 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''''''' 20 ' Demonstration of parsing the NMEA string produced by a GPS module 30 ' Geoff Graham - Sept 2011 40 ' 50 ' All GPS modules are guaranteed to produce the GPRMC string60 ' See http:// 70 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''''''' 80 SetPin 1,6,930 100 max = 20 ' maximum nbr of params 110 Dim arg$(max) ' used to hold the data fields 120 ' 130 Open "COM1:4800" As #1 140 ' 150 Do ' loop forever 160 GoSub 800 ' get the next line 170 If arg$(0) = "GPRMC" Then ' GPRMC contains lat/long 180 If arg$(2) = "A" Then ' "A" means locked on to satellite 185 If flag=1 Then GoTo 280 'JUMP TO TIME DISPLAY 190 Print "Latitude = "; Left$(arg$(3), 2); " "; Mid$(arg$(3), 3); 200 Print " "; arg$(4); 210 Print " Longitude = "; Left$(arg$(5), 3); " "; Mid$(arg$(5), 4); 220 Print " "; arg$(6) 230 Else 240 Print "GPS searching..." 250 EndIf 260 EndIf 270 Loop 280 Print "Time "arg$(1) 281 x=x+1 'DELAY 282 If x=10 Then flag=0:IReturn 283 GoTo 160 290 ' 300 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''' 310 ' subroutine to load the GPS data fields into the array arg$() 320 ' returns with the array populated 800 Do ' subroutine start 810 Do While Input$(1, #1) <> "$" : Loop ' wait for the start 820 For i = 0 To max 830 arg$(i) = "" ' clear ready for data 840 Do ' loops until a specific exit 850 x$ = Input$(1, #1) ' get the character 860 If x$ = "," Then Exit ' new data field, increment i 870 If x$ = "*" Then Return ' we have all the data so return 880 arg$(i) = arg$(i) + x$ ' add to the data 890 Loop ' loop back for the next charurn 900 Next i ' move to the next data field 910 Print "Corrupt data..." ' exceeded max data items 920 Loop 930 Flag=1:x=0 'INTERRUPT TO TIME DISPLAY 940 GoTo 160 "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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CircuitGizmos Guru Joined: 08/09/2011 Location: United StatesPosts: 1421 |
That is a bit tough to follow. I think you are jumping into the middle of a loop from outside the loop. Even without the interrupt code, there is a line (283) that jumps into a loop. Micromites and Maximites! - Beginning Maximite |
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| palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
Yeh, how stupid not to see that I should be jumping back to 150 not 160. Sorry all. Paul. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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| greybeard Senior Member  Joined: 04/01/2010 Location: AustraliaPosts: 158 |
I'd strongly suggest that you lose the line numbers and use labels only where needed for targets. Also consider indentation. The reasoning behind doing so is to reduce the 'clutter' and make your code a little more readable. Something else to consider is write and comment code on the assumption that in 10 years time you will have to debug it. ie simple, structured and formatted code leaves the brain cells to concentrate on the content and intention of the code. Not get bogged down just trying to follow it. If you are struggling with code size then all bets are off but otherwise, the memory and storage are already paid for, you may as well us them 
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| palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1805 |
Thanks for the suggestions, but that code was only meant to be a demo of the problem. Gizmo, that was not my problem after all if you look at Geoffs code he does the same thing line 870 jumps back to line 160. The problem was with the Ireturn so I fixed the problem by Interrupting to a routine which simply sets a flag and Ireturns immediately. The program then does what I want for a time before the flag is reset to zero and the main program resumes. All is now working fine. Thanks to all who helped. Paul. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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