Shifting Data
oodes
Posts: 131
Hello Guys ,
I'm a bit of a newby so this might be a simple question for some of you I hope. Im reading data from a text file on a SD card and displaying it on an LCD and also the PST. The Data stream is 40 characters long. I have 2 text files and I choose which one to open and read by the state of a pin. If my pin is 0 I open " Bibliog.txt" and read in the first 40 characters and display it.
But I want it so that when I push the button again (active low) I read in the following 40 characters (40-79) of the text file. Do I need to shift the address >>40 times?? Apologies for the poor code , i'm a bit of a virgin
x := sdfat.popen(string("Bibliog.txt"), "r")
if x <> 0
lcd.move(1,1)
lcd.str(string("File Not Found"))
repeat
sdfat.pread(@data1,40)
sdfat.pclose
lcd.move(1,1)
lcd.str(string("Bibliog.txt"))
delay
lcd.clear
lcd.move(1,1)
lcd.str(@data1)
pst.Start(115_200)
pst.Str(@data1)
delay
lcd.clear
repeat
if INA[11]==0 ' My push button connected here
???????????????? 'here's my problem
DAT
data1 long "Bibliog.txt",0
data2 long "Cheats.txt",0
I'm a bit of a newby so this might be a simple question for some of you I hope. Im reading data from a text file on a SD card and displaying it on an LCD and also the PST. The Data stream is 40 characters long. I have 2 text files and I choose which one to open and read by the state of a pin. If my pin is 0 I open " Bibliog.txt" and read in the first 40 characters and display it.
But I want it so that when I push the button again (active low) I read in the following 40 characters (40-79) of the text file. Do I need to shift the address >>40 times?? Apologies for the poor code , i'm a bit of a virgin
x := sdfat.popen(string("Bibliog.txt"), "r")
if x <> 0
lcd.move(1,1)
lcd.str(string("File Not Found"))
repeat
sdfat.pread(@data1,40)
sdfat.pclose
lcd.move(1,1)
lcd.str(string("Bibliog.txt"))
delay
lcd.clear
lcd.move(1,1)
lcd.str(@data1)
pst.Start(115_200)
pst.Str(@data1)
delay
lcd.clear
repeat
if INA[11]==0 ' My push button connected here
???????????????? 'here's my problem
DAT
data1 long "Bibliog.txt",0
data2 long "Cheats.txt",0
Comments
Hello Guys ,
I'm a bit of a newby so this might be a simple question for some of you I hope. Im reading data from a text file on a SD card and displaying it on an LCD and also the PST. The Data stream is 40 characters long. I have 2 text files and I choose which one to open and read by the state of a pin. If my pin is 0 I open " Bibliog.txt" and read in the first 40 characters and display it.
But I want it so that when I push the button again (active low) I read in the following 40 characters (40-79) of the text file. Do I need to shift the address >>40 times?? Apologies for the poor code , i'm a bit of a virgin
PUB Init1 | x , x := sdfat.popen(string("Bibliog.txt"), "r") if x <> 0 lcd.move(1,1) lcd.str(string("File Not Found")) repeat sdfat.pread(@data1,40) sdfat.pclose lcd.move(1,1) lcd.str(string("Bibliog.txt")) delay lcd.clear lcd.move(1,1) lcd.str(@data1) pst.Start(115_200) pst.Str(@data1) delay lcd.clear repeat if INA[11]==0 ???????????? ' Here is the problem DAT data1 long "Bibliog.txt",0 data2 long "Cheats.txt",0I ask because, if it's only 2 groups of 40 characters x 2 files, then you could just read in all 4 strings of 40 bytes during initialization and select which one you want to display. How big are these files (how many 40 byte entries)? How you implement this depends a lot on that. For example, if you have a 64K byte EEPROM, you could read both files into fixed locations in the EEPROM, then access the entries randomly very easily. If these files could be large, maybe you could use one of the SD card drivers that supports more than one file open at a time (for reading) and just open both of them and read 40 bytes at a time from both selecting which one you want each time the button is pushed.
PUB Begin DIRA[16]~~ 'DISPLAY ON/OFF OUTA[16]~~ 'DISPLAY ON lcd.start lcd.clear lcd.move(6,2) lcd.str(string("Hello Rivtec")) waitcnt(clkfreq * 2 + cnt ) lcd.clear lcd.Home lcd.str(string("Mounting Card")) MountCard Delay if INA[11]==0 lcd.move(1,1) lcd.str(string("Bibliog.txt selected")) delay lcd.clear Init1 if INA[14]==0 lcd.move(1,1) lcd.str(string("Cheats.txt selected")) delay lcd.clear Init2Basically I just read the first 40 bytes of whatever file is open and display it on the LCD and PST. If I push the button again ,clear the LCD read the next 40 bytes and display, and if pushed again the next 40 and so on. I'm just unsure how to structure the code
''File : Project 2 {{1) Copy the files 'Bibliog.txt' and 'Cheats.txt' to the SD card and insert in ProGen. 2) Read the filenames from the Sd card and display on two differnt lines of LCD. 3) Using the two opto-isolated inputs of ProGen (P11 & P14), select either the upper file (P11) or lower file (P14). 4) Open the selected file. 5) If P11 is operated, display the first 80 characters of the text file on LCD and transmit to serial terminal. If P14 is operated, display the last 80 characters of teh text file on LCD and transmit to serial terminal. 6) Each time P11 is operated, display and transmit the next 80 characters from text file. Each time P14 is operated, display and transmit the previous 80 characters from text file. 7) If '~' is pressed at any stage then close the open file and return to step 2. " }} CON _clkmode = xtal1 + pll16x ' set the clk mode _xinfreq = 5_000_000 ' set the incoming frequency OBJ ' objects being used and required pst: "Parallax Serial Terminal" lcd : "LCD_20x4_4Bit" sdfat: "fsrw" PUB Begin | r ,d DIRA[16]~~ ' DISPLAY ON/OFF OUTA[16]~~ ' DISPLAY ON lcd.start lcd.clear lcd.move(6,2) lcd.str(string("Hello Rivtec")) waitcnt(clkfreq * 2 + cnt ) lcd.clear lcd.str(string("Mounting Card")) MountCard ' Call Mountcard Method repeat r := sdfat.popen(string("Bibliog.txt"), "r") ' Open and Read the file name Bibliog.txt is present if r <> 0 ' if other than 0 is returned lcd.move(1,1) lcd.str(string("File Not Found")) ' Display File not found repeat lcd.move(1,1) lcd.str(string("Bibliog.txt")) ' Display Bibliog.txt r := sdfat.popen(string("Cheats.txt"), "r") ' Open and Read the file name Cheats.txt is present if r <> 0 ' if other than 0 is returned lcd.move(1,3) lcd.str(string("File Not Found")) ' Display File not found repeat lcd.move(1,3) lcd.str(string("Cheats.txt")) ' Display Cheats.txt delay lcd.clear ' Initialize local variable d = 0 d:=0 repeat until d ==1 ' repeat loop below until d =1 if INA[11] & INA[14] ==1 ' If the pins P11 and P14 are high (push button switch connected , 1 when not pushed lcd.str(string("No file selected")) ' Display No file selected repeat while INA[11] & INA[14] ==1 ' repeat while both switches are not pushed if INA[11]==0 ' If switch on P11 is pushed lcd.clear lcd.move(1,1) lcd.str(string("Bibliog.txt selected")) ' Display Bibliog.txt selected delay lcd.clear Init1 ' Call the Init1 method d:=1 ' set d = 1 if INA[14]==0 ' If switch on P14 is pushed lcd.clear lcd.move(1,1) lcd.str(string("Cheats.txt selected")) ' Display Cheats.txt selected delay lcd.clear Init2 ' Call Init2 d:=1 PUB Init1 | x, Idx, a ,c x := sdfat.popen(string("Bibliog.txt"), "r") ' Open the file Bibliog for read if x <> 0 ' If other than 0 is returned lcd.move(1,1) lcd.str(string("File Not Found")) ' Display File not found repeat pst.Start(115_200) ' Start the pst and set the baud rate to 115,200 pst.clear ' clear the pst lcd.clear ' clear the lcd repeat Idx from 0 to 79 ' Repeat Idx from 0 to 70 (we want 80 characters which fills LCD) a:=sdfat.pgetc ' gets a character at a time from Bibliog.txt , character is declared a local variable 'a' case Idx 0 : lcd.move(1,1) ' For values of Idx from 0-19 display on top line on the LCD 20 : lcd.move(1,2) ' For values of Idx from 20-39 display on 2nd line on the LCD 40 : lcd.move(1,3) ' For values of Idx from 40-59 display on 3rd line on the LCD 60 : lcd.move(1,4) ' For values of Idx from 60-79 display on 4th line on the LCD if a > $19 and a < $7F ' if a is not a control code in ascii chart (prevents junk being diplayed that may be in text file) lcd.char(a) ' display 'a' on lcd pst.char(a) ' display 'a' on pst c:=0 ' Initize 'c' local variable to 0 repeat until c == $7E ' repeat the loop below until '~' is pressed if INA[11]==0 ' if P11 is pushed again lcd.clear ' clear the lcd repeat Idx from 0 to 79 ' And display the next 80 charcters on the file a:=sdfat.pgetc case Idx 0 : lcd.move(1,1) 20 : lcd.move(1,2) 40 : lcd.move(1,3) 60 : lcd.move(1,4) if a > $19 and a < $7F lcd.char(a) pst.char(a) c:=pst.rxcheck ' check if '~' has pushed , if so exit the loop lcd.clear ' clear lcd screen PUB Init2 | y , Indx, b ,size ,position , c y := sdfat.popen(string("Cheats.txt"), "r") ' Open the file Cheats.txt for read if y <> 0 ' If other than 0 is returned lcd.move(1,3) lcd.str(string("File Not Found")) ' Display File not found repeat pst.Start(115_200) ' Start the pst and set the baud rate to 115,200 pst.clear ' Clear the pst lcd.clear ' clear the lcd size:=sdfat.get_filesize ' get the size of the file so we can start displayed the data from the end of file position:=(size - 80) ' declare local variable 'position' to be filesile - 80 charactes so we print the last 80 characters sdfat.seek(position) ' seek the position, which is end of text (file - 80 characters) repeat Indx from 0 to 79 ' Repeat Indx from 0 to 70 (we want 80 characters which fills LCD) b:=sdfat.pgetc ' gets a character at a time from cheats.txt , character is declared a local variable 'b' case Indx ' case statement 0 : lcd.move(1,1) ' For values of Idx from 0-19 display on top line on the LCD 20: lcd.move(1,2) ' For values of Idx from 20-39 display on 2nd line on the LCD 40: lcd.move(1,3) ' For values of Idx from 40-59 display on 3rd line on the LCD 60: lcd.move(1,4) ' For values of Idx from 60-79 display on 4th line on the LCD if b > $19 and b < $7F ' if b is not a control code in ascii chart (prevents junk being diplayed that may be in text file) lcd.char(b) ' display whatever 'b' is on lcd pst.char(b) ' display whatever 'c' is on pst delay c:=0 ' Initize 'c' local variable to 0 repeat until c == $7E ' repeat the loop below until '~' is pressed if INA[14]==0 ' if P14 is pushed again lcd.clear ' clear the lcd position:=position-80 ' position is now (position - 80 charcters) sdfat.seek(position) ' seek this position repeat Indx from 0 to 79 ' repeat the process 80 times b:=sdfat.pgetc ' display on LCD case Indx 0 : lcd.move(1,1) ' In line sequence 20: lcd.move(1,2) 40: lcd.move(1,3) 60: lcd.move(1,4) if b > $19 and b < $7F ' no junk lcd.char(b) ' display on LCD pst.char(b) ' display on Pst c:=pst.rxcheck ' check if '~' has pushed , if so exit the loop lcd.clear ' clear lcd screen PUB MountCard|r {{ Checks if an Sd card is mounted}} if INA[7] == 1 ' if card detect is high( 0 when card present) 'INA' monitors the state of a pin lcd.move(1,2) lcd.str(string("No Card Inserted")) ' Display No card inserted lcd.move(1,3) lcd.str(string("Insert Card")) ' Display Insert card outa[27]~ ' Pin 27 set to 0 (input) repeat until INA[7]==0 ' repeat until INA[7] goes low i.e card present reboot ' reboot when card is present if INA[2] == 1 'write protect same as above only now checks if card is write protected lcd.move(1,2) lcd.str(string("Card Is")) lcd.move(1,3) lcd.str(string("Write Protected.")) repeat r := sdfat.mount(3) ' BASEPIN (D0)= 3, CLK = 4, DI = 5, CS = 6 if r <> 0 ' if return value is other than 0 lcd.move(1,2) lcd.str(string("Cannot find Card")) ' display cannot find card repeat lcd.move(1,2) lcd.str(string("Card Mounted")) ' if successful display Card mounted. delay lcd.clear PUb Delay {{ just a delay function to save writing it all the time}} waitcnt(clkfreq * 2 + cnt)