Max7219 and a DS1620
Nick Waldvogel
Posts: 71
How can I get the max7219 to display the temp on a 3 digit display? I am using a DS1620 as a temp prob and I have it sending out on a Pink but for some reason I can't seem to figure out how to properly display it this way! Thanks for your time!! I love learning this stuff!! 
Comments
·· Here is a project that uses the DS1620 and the MAX7219...Between the two you should be able to come up with enough examples to do what you want.
http://forums.parallax.com/showthread.php?p=552892
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Chris Savage
Parallax Tech Support
csavage@parallax.com
' Hardware interface with the 7219: DATA_n CON 7 ' Bits are shifted out this pin # to 7219. CLK CON 5 ' Data valid on rising edge of this clock pin. Load CON 6 ' Tells 7219 to transfer data to LEDs. decode CON 9 ' Decode register; a 1 turns on BCD decoding. brite CON 10 ' " " " intensity register. scan CON 11 ' " " " scan-limit register. switch CON 12 ' " " " on/off register. Test CON 15 ' Display Test Mode XX VAR Byte 'General purpose variable, byte. DegF VAR Byte 'Variable for Deg F. DegC VAR Byte 'Variable for Deg C max_dat VAR Word ' Word to be sent to MAX7219. index VAR Nib ' Index into setup table. temp VAR Nib ' Temporary variable used in outputting digits. nonZ VAR Bit ' Flag used in blanking leading zeros. d7219 VAR Word ' Data For MAX7219 DegF0 VAR DegF.BIT0 DegF1 VAR DegF.BIT1 DegF2 VAR DegF.BIT2 odd VAR index.BIT0 ' Lsb of index. 'Note: DS1620 has to be preprogramed for mode 2. FOR index = 0 TO 7 ' Retrieve 8 items from table. LOOKUP index,[noparse][[/noparse]scan,4,brite,1,decode,$1F,switch,1],max_dat SHIFTOUT DATA_n,CLK,MSBFIRST,[noparse][[/noparse]max_dat] IF odd = 0 THEN noLoad ' If odd is 1, pulse Load line. PULSOUT Load,1 NoLoad: ' Else, don't pulse. NEXT ' Get next item from table. HIGH 13 'Select the DS1620. SHIFTOUT 15, 14, LSBFIRST, [noparse][[/noparse]238] 'Send the "Start Conversions" command. LOW 13 'Do the command. '------- Main--------- DO 'Going to display every 1 sec. HIGH 13 'Select the DS1620 SHIFTOUT 15, 14, LSBFIRST, [noparse][[/noparse]170] 'Send the "Get Data" command. SHIFTIN 15,14,LSBPRE, [noparse][[/noparse]xx] 'Get the data. LOW 13 'End the command. DegC = xx / 2 DegF = DegC * 9 / 5 + 32 'Convert data. DEBUG HOME DEBUG "The Temp is ",DEC DegF,32,"Degrees", CR GOSUB Show_Temp LOOP Show_Temp: index = 1 d7219 = 8 GOSUB Show_Max_Temp index = 2 d7219 = 8 GOSUB Show_Max_Temp index = 3 d7219 = DegF0 GOSUB Show_Max_Temp index = 4 d7219 = DegF1 GOSUB Show_Max_Temp index = 5 d7219 = DegF2 GOSUB Show_Max_Temp RETURN Show_Max_Temp: SHIFTOUT DATA_n,CLK, MSBFIRST, [noparse][[/noparse]index, d7219] PULSOUT Load,5 ' Latch Data RETURN▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com