Serial 4 digit, 7-segment LED display

Hugh

Has anyone played with one of these four-digit, seven-segment LED displays with TTL / SPI / I²C interfaces? If so, do you know of any code with which I could test mine?

It should be really simple but I am not sure mine is actually working as it should ("a bad workman blames his tools").

Thanks
Hugh

Ron Czapala

You need to be a little more specific since the control codes can be different depending on who makes/sells the board.

Are you talking about the ones from Sparkfun? A link to the item would help.


Here is some test code I used with some older Sparkfun models

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000
  DecPts      =  $77   ' "w" Decimal point command
  Brightness  =  $7A   ' "z" Brightness command 0(bright) - 254(dim)
  setBaud     =  $7F   ' DEL 0=2400, 1=4800, 2=9600, 3=1440, 4=19200, 5=38400, 6=57600
  ClearScr    =  $76   ' "v" clear display and set position to 1st digit
  Digit1      =  $7B   ' "{" set individual segments for digit one
  Digit2      =  $7C   ' "|" set individual segments for digit two
  Digit3      =  $7D   ' "}" set individual segments for digit three
  Digit4      =  $7E   ' "~" set individual segments for digit four
  TX_PIN        = 0
  BAUD          = 9_600
VAR
                     
OBJ
  Seg7     : "FullDuplexSerial.spin"    '   : "simple_serial"                              ' bit-bang serial driver    

PUB Main
  Seg7.start(TX_PIN, TX_PIN, %1000, BAUD)      ' ignore tx echo on rx  
  waitcnt(clkfreq / 100 + cnt)             
  Seg7.tx(ClearScr)
  Seg7.tx(Brightness)
  Seg7.tx(4)
  waitcnt(clkfreq + cnt)
  Seg7.str(string("1234"))
  waitcnt(clkfreq + cnt)
  Seg7.dec(1567) 
  repeat  
  waitcnt(clkfreq + cnt)
  Seg7.stop
DAT
  testmsg byte "testing", 0  

Hugh

Thanks Ron, your code works perfectly. I'd used the wrong settings for FDS.

I'd intended to set the picture so it was possible to 'click through' to the spec but must have sponged that up also.

Cheers
Hugh

Ron Czapala

Hugh wrote: »

Thanks Ron, your code works perfectly. I'd used the wrong settings for FDS.

I'd intended to set the picture so it was possible to 'click through' to the spec but must have sponged that up also.

Cheers
Hugh

Actually cutting and pasting the code screwed up the FDS settings - it should read

Seg7.start(TX_PIN, TX_PIN, %1000, BAUD) ' ignore tx echo on rx

Here is a video I did using a Basic Stamp

Hugh

Thanks Ron,

It works ver well - thanks!