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have had a need to use the TM1637 4 digit display module
please refer to link for the display module circuit and display unit used
http://www.picbasic.co.uk/forum/showthread.php?t=23968
Thanks to richard for help on the start/stop/ write timing section
hope it of use to save some time when using this module
cheers
Sheldon
Code:
'* Version : 0.0 *
'* Notes : Driver Libary for TM1637 chip *
'* : For use on 4 digit with centre colon only *
'* : Note: Driver does not support the keyscan option *
'*******************************************************************************
' Description: *
' This include supports 4 digits, no Decimal Points on each digit *
' and 1 colon in centre of 4 digits only *
' No keyscan support setup on the TM1637 fuctions *
' *
' Operation: *
' min voltage for Red, Yellow LED digits is 3.3 volt *
' min voltage for Green , Blue LED digits is 5v *
' min clock width = 400ns *
' min data setup = 100ns + hold =100ns *
' The Clock and Data Pin have pull up 4k7 resitor, *
' with a 100pf cap to ground to reduce interfance buit into module *
' The 2 colon led segments are connected to anode Com2,cath= seg8 *
' *
' Features : *
' Use either raw segment values or decimal numbers *
' (with and without leading zero) *
' Set either the whole display or any digit independently *
' Control the brightness *
' Test display segments display *
'=============================================================================='
' TM1637 4 DIGIT COMMON ANODE - 1 COLON DISPLAY MODULE *
' *
' Note: COLON = Grid2 - seg8(dp)- No other DP on this display *
' ----------------------------------------- DISPLAY FACING *
' | | *
' | ______ _____ _____ _____ | *
' | | A | | | | | | | | *
' | |F B| | | | | | | 0 ----- CLK *
' | |_____| |_____| O |_____| |_____| o ----- DIO *
' | | G | | | | | | | 0 ----- VCC *
' | |E C| | | O | | | | 0 ----- GND *
' | |__D__| |_____| |_____| |_____| | *
' | dig1 dig2 dig3 dig4 | *
' | grid1 grid2 grid3 grid4 | *
' ----------------------------------------- *
' *
' =============================================================================*
' Command byte information TM1637 *
' Note: Bit5= 0 ,bit4 = 0 always *
' bit7 : Bit6 *
' 0 : 1 = Data Command *
' 1 : 0 = Display control Command *
' 1 : 1 = Address command '
' +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ *
' Data Command table ( bit7 = 1 , bit6 = 0 , bit5=0,bit4 =0) Hex value $4x *
' *
' Bit1:Bit0 *
' 0 : 0 = Write Data to display *
' 1 : 0 = Read key scan *
' 0 : 1 = reserved *
' 1 : 1 = reserved *
' Bit2 0 = Auto Address Adding , 1= Fixed Address *
' Bit3 0 = Normal Mode 1 = Test Mode *
' = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =*
' Display Control Commnad table ( bit7=1 , Bit6 =0) hex value $8x *
' Bit2:Bit1:Bit0 - display brightness control level 0 = low , level 7 = high *
' 0 : 0 : 0 Display Brightness 1/16 - level 0 *
' 0 : 0 : 1 Display Brightness 2/16 - level 1 *
' 0 : 1 : 0 Display Brightness 4/16 - level 2 *
' 0 : 1 : 1 Display Brightness 10/16 - level 3 *
' 1 : 0 : 0 Display Brightness 11/16 - level 4 *
' 1 : 0 : 1 Display Brightness 12/16 - level 5 *
' 1 : 1 : 0 Display Brightness 13/16 - level 6 *
' 1 : 1 : 1 Display Brightness 14/16 - level 7 *
' *
' Bit3 0 = Display Off 1 = Display On *
' *
' = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =*
' Grid Segment Address Command Table ( Bit7= 1 ,Bit6 = 1 ) Hex Value = $Cx *
' Display Adreess Registers *
' Bit3-Bit0 $C0 = Grid1(dig1), $C1 = Grid2(dig2+colon) ,$C2=Grid3 ,$C3=Grid4 *
' *
' Eech bit for each Grid byte controls a digit led Segment *
' Bit7=Seg8(DP,COlON),Bit6=Seg7(led-G),Bit5=Seg6(led-F),Bit4=Seg5(led-E) *
' Bit3=Seg3(led-D),Bit2=Seg2(led-C),Bit1=Seg1(led-B),Bit0=Seg1(led-A) *
' *
'==============================================================================*
TM_DIO_OUT var LATB.2 ' Data Pin OUT TM1637 include - 4dig 7seg Display Module
TM_DIO_IN VAR PORTB.2 ' Data Pin In ( not used )
TM_CLK var LATB.3 ' Clock Pin- set in TM1637 include - 4dig 7seg Display Module
DIR_TM_DIO var TRISB.2 ' Direction control for tm_dio pin 0 = out 1 = in
TM1637_WR con $40 ' write data command , with auto Address adding , display mode = normal
TM1637_WR_fixed con $44 ' write data command , with fixed Address , display mode = normal
Cmd_Dig_Seg con $C0 ' Grid Segment Address Command $C0 - $C3 used on this module
TM1637_Dsp_CTL con $80 ' display bright control command , bit3-0=display off 1= on ,bit2-0 brightness 0 - low 7 = high
Dig_7seg var byte[4] ' 4 byte array byte for each digit in use
TM1637_Data var byte ' value for each digit / segment in send command
YY var byte ' geneeral loop varable
g_num var word ' reqested number or chr to be dipslayed
TM1637_Bright var byte ' display brightness value (0-7) 0=low to 7=high brighness
Colon_On var bit ' select if the colon segment is on/off
TM1637_On var bit ' select display on / off bit for command3
R_Justfy var bit ' set leading 0 if digit value 0 displayed over the digits
DIR_TM_DIO = 0 ' set direction output as start
TM_CLK = 1 ' SET HIGH AT START - modual has pullups
TM_DIO_out = 1 ' set high at start - module has pullups
goto Jumpover_TM1637
'======================================
TM1637_Startup:
' Command to do test pattern at device starup
'---- each digit turn on in seq, all digits
Dig_7seg(0) = 0
Dig_7seg(1) = 0
Dig_7seg(2) = 0
Dig_7seg(3) = 0
TM1637_on = 1
for g_num = 0 to 3
Dig_7seg(g_num) = $FF
TM1637_On = 1
TM1637_Bright = 7
gosub WR_4dig
pause 200
next g_num
gosub TM1637_flash ' flash the display 3 times
gosub TM1637_off ' turn off display
return
' -------------------------------
TM1637_flash:
' flash the display 3 times with current values and brightness
' if display was off prior to call , will leave it off after , visa versa if display was on prior
for g_num = 0 to 5 ' flash display on / off 3 times
toggle TM1637_On
TM1637_Bright = 7
gosub WR_Disp_Command3
pause 300
next g_num
return
'---------------------------------------------------------
TM1637_Off:
' turn off the tm1637 display
TM1637_On = 0 ' set bit to 0 turn off display
gosub WR_Disp_Command3 ' send the commands to display, other values dont care as display tuned off
return
'--------------------------------------
WR_4dig:
' assumes each digit data 7 segment info varable ( dig1_7seg,dig2_7seg, dig3_7seg dig4_7seg )
' assumes brightness setting value for command3 ( tm1637_bright)
' assumes colon bit,TM1637_ON Bit , Dig_7seg(0-3) value
' TM1637_On = 1
' Colon_On = 1
' TM1637_Bright = 7
gosub Start_data ' start seq
TM1637_Data = TM1637_WR ' set write data command1 , with auto Address increment , display mode = normal
Gosub Write_Tm1637 ' write to module
gosub Stop_data ' stop seq after data command1
gosub Start_data ' start seq for command2
TM1637_Data = Cmd_Dig_Seg ' grid1 start address for auto increment
Gosub Write_Tm1637 ' write to module
TM1637_Data = Dig_7seg(3) ' digit 4 Data on grid1
Gosub Write_Tm1637 ' write to module
TM1637_Data = Dig_7seg(2) ' digit 3 Data on Grid2
TM1637_Data = TM1637_Data + (Colon_On << 7) ' add colon bit setting (bit7) to digit2 data for grid2
Gosub Write_Tm1637 ' write to module
TM1637_Data = Dig_7Seg(1) ' digit 2 data for grid3
Gosub Write_Tm1637 ' write to module
TM1637_Data = Dig_7Seg(0) ' digit 1 data for grid4
Gosub Write_Tm1637 ' write to module
Gosub Stop_data ' send stop seq to show end of address data
WR_Disp_Command3: ' Label to write display command3 only , assumes dig_7seg(0-3)+ colon setting, brightness , display on /off setting
gosub Start_data ' start seq for command 3 to start
TM1637_Data = TM1637_Dsp_CTL ' build display command3 byte
TM1637_Data = TM1637_Data +(TM1637_On <<3) ' add display on/off bit setting(bit3)to command3
TM1637_Data = TM1637_Data + TM1637_Bright ' add display brighness value ( 0-7 ) to byte command3
Gosub Write_Tm1637 ' write to module
gosub Stop_data ' stop seq
return
'-----------------------------------------------------------------------------
' digits placed and display left to right with 4th digit first 1digit last
' routine can set all 4 values
' assumes R_Justfy value, g_num
Put_4dig:
TM1637_Data = g_num DIG 3 ' get 4th digit value into temp varable
gosub lookup_dig ' convert value to 7seg display value
Dig_7seg(3) = TM1637_Data ' place 7seg value into digit1 including "0"
if TM1637_Data = $3F then ' if it 7seg "0" then
if R_Justfy = 0 then Dig_7seg(3) = 0 ' if flag not set dont show digit
endif
Put_3dig:
TM1637_Data = g_num DIG 2 ' get 3rd digit value into temp varable
gosub lookup_dig ' convert value to 7seg display value
Dig_7seg(2) = TM1637_Data ' place 7seg value into digit1 including "0"
if TM1637_Data = $3F then ' if it 7seg "0" then
if R_Justfy = 0 then Dig_7seg(2) = 0 ' if flag not set dont show digit
endif
Put_2dig:
TM1637_Data = g_num DIG 1 ' get 2nd digit value into temp varable
gosub lookup_dig ' convert value to 7seg display value
Dig_7seg(1) = TM1637_Data ' place 7seg value into digit1 including "0"
if TM1637_Data = $3F then ' if it 7seg "0" then
if R_Justfy = 0 then Dig_7seg(1) = 0 ' if flag not set dont show digit
endif
Put_1dig:
TM1637_Data = g_num DIG 0 ' get 1st digit value into temp varable
gosub lookup_dig ' convert value to 7seg display value
Dig_7seg(0) = TM1637_Data ' place 7seg value into digit1 including "0"
return
'------------------------------------------------------------------------------
lookup_dig:
' converts selected dec value to 7seg display value
' digits display 0 1 2 3 4 5 6 7 8 9
lookup TM1637_Data,[$3F,$06,$5B,$4F,$66,$6D,$7D,$07,$7F,$6F],TM1637_Data
return
'-----------------------------------------------------------------------------
test_txt:
' place "CH:" txt and current Rf CH value onto display ,
' use R_justfy leading 0 for 2 digits
Dig_7seg(3) = $39 '"C"
Dig_7seg(2) = $76 '"H"
Colon_On = 1 '":"
g_num = 1 ' get the current RF CH value
R_Justfy = 1 ' set leading 0 if single digit
gosub put_2dig ' put 2 digits values for location dig3, dig4
TM1637_Bright = 7 ' Set display to full brightness - value (0-7) 0=low to 7=high brighness
TM1637_On = 1 ' select display on in command3
gosub WR_4DIG ' write the values to display
return
'--------------------------------------------
' signal requirments at start of command
Start_data:
tm_CLK = 1
tm_DIO_out = 1
@ NOP
Tm_DIO_out = 0
@ NOP
tm_CLK = 0
return
'------------------------------------
' signal requirement after command is sent
Stop_data:
tm_CLK = 0
tm_DIO_out = 0
tm_CLK = 1
@ NOP
tm_DIO_out = 1
@ NOP
return
'--------------------------------------------
Write_TM1637:
' assumes TM1637_Data
' commands/ data sent LSbit first
yy= 0
for yy = 0 to 7 ' send 8 bits of data
tm_CLK = 0
tm_dio_out = TM1637_Data.0(yy)
tm_CLK = 1
@ NOP
Next yy
tm_CLK = 0 ' clock in data to look for the Ack from TM1637
DIR_TM_DIO = 1 ' set Data pin direction to input , release
tm_CLK = 1 ' clock in ACK data on rising edge from TM1637
@ NOP ; allow time for input of ACK
@ NOP
@ NOP
tm_CLK = 0 ' release DIO on oomplete 9th clock
@ NOP
DIR_TM_DIO = 0 ' set Data pin direction to output
return
'----------------
'show_number:
'send number example
g_num = 32
R_Justfy = 1 ' place leading 0 in display
gosub Put_4dig ' place 4 digit values
TM1637_On = 1
Colon_On = 0
TM1637_Bright = 7
gosub WR_4dig
'return
'-------------------------------------
'==========================================================================
Jumpover_TM1637: 'Jumpover code for PBP compile requirements
Re: K42 and Timer Interrupts
Thanks for the explanation.
Ioannis - 28th April 2025, 19:28I misinterpreted these paragraphs. My understanding was to have ASYNC cleared and use Fosc/4.
Ioannis