' B7AB3EDA542BA398604FDBFBD724B49CC92BAEBA467FC6B42F179DD144212706C0756D59ACD0BE12A4CB00D320906441E88FCBCCBBBE0385921AB2E88510844F
' sRipeTech
' 2C102C09B9 2025-06-05 16:53:39 
' ########################################################################################
' Adafruit MCP2221 breakout board
' driving an    eletechsup DM43B04
'
' A script written for  PlodWare Scripter
' 2025-06-03
' ########################################################################################
' This demo uses a minimal ammount of code to provide the 
' access to 2 of the functions exposed by the MCP2221A DLL
' to support driving the   eletechsup DM43B04  4-digit 7-segment display board.
' ---------------------------------------------------------
' The following reflects my (quite likely incomplete, or even incorrect) understanding
' of the 7-segment display board marked as
'     eletechsup    DM43B04
' ---------------------------------------------------------
' The MCP2221A DLL expects the  Mcp2221_I2cWrite  interface to have an i2c address.
' The address is (for 7-bit devices) shifted 1 bit to the left, and then the
' least significant bit is set to 0 (for a write operation).
'
' This does not seem to be consistant with the DM43B04.
'
' Whilst the DM43B04  is a "sort" of i2c device it has some unique aspects.
' It does NOT really have an i2c address.
'
' Every DM43B04 command consists of two bytes: 
'    a command code, followed by a data byte
'
' ***Fortunately*** the command codes all have bit-0 = 0
' 
' So when we use the   Mcp2221_I2cWrite  interface, we pass it
'    A command byte  - which we shift RIGHT one bit, and pretend that it is the i2c address.
'    And a data byte - unchanged.
' see   function SSegWr  below.
' ---------------------------------------------------------
' Here are the DM43B04 commands:
' display off:            0x48 , 0x00
' display on:             0x48 , 0x01
' brightness of 7 segments:  
'    0x48 followed by one of  Dim 0x11, 0x21,..0x71, 0x01 bright
' brightness of 8 segments (seems to automatically turn the decimal point on as well):
'    0x48 followed by one of  Dim 0x19, 0x29,..0x79, 0x09 bright
' set left most display : 0x68 , 0x??  where ?? is a bit map of the 8 display parts. See below.
'                       : 0x6A , 0x??   
'                       : 0x6C , 0x??   
' set right most display: 0x6E , 0x??   
' ---------------------------------------------------------
' A display character consists of 8 parts:  x=decimal point, plus 7 bars (a..g)
'      
'     -a-
'  f |   | b
'     -g-
'  e |   | c
'     -d-  x
 
'
' We combine these 8 parts in to a single byte: 0x0xgfedcba
' ---------------------------------------------------------

newscript
report()

dim MCP_defaultVID =  0x4D8
dim MCP_defaultPID =  0x0DD

dim mcpDLL = dll.open ("mcp2221_dll_um_x64")

IF ( ! mcpDLL   ) THEN
   report (  "MCP:  Could not open the DLL file." )
   STOP
END IF

' void* Mcp2221_OpenByIndex(unsigned int VID, unsigned int PID, unsigned int index)

dim  _MCP_OpenByIndex = dll.link(mcpDLL, "Mcp2221_OpenByIndex", 3,"unsigned"   )

' int Mcp2221_I2cWrite(void* handle, unsigned int bytesToWrite, unsigned char slaveAddress,
'      unsigned char use7bitAddress, unsigned char* i2cTxData)

dim  _MCP_I2CWrite    = dll.link(mcpDLL, "Mcp2221_I2cWrite"   , 5,"signed32"  )

' request access to the 0'th device.
dim mcp_Handle =  _MCP_OpenByIndex ( MCP_defaultVID , MCP_defaultPID , 0 )
IF ( mcp_handle == -1 ) then
   report (  "MCP:  Could not connect to target device." )
   STOP
END if

' ---------------------------------------------------------

FUNCTION SSegWr ( p0 , p1 )
   dim outBytes = byteArray (1,p1)
   _MCP_i2cWrite ( mcp_handle , 1 , p0 rshift 1 , 7, outbytes)
END function

' ---------------------------------------------------------
SSegWr( 0x48 , 0x00)
SSegWr( 0x48 , 0x01) ' enable display
SSegWr( 0x48 , 0x31) ' set brightness (lowish!)   

' clear the display
SSegWr( 0x68 ,  0)' left-most display
SSegWr( 0x6A ,  0)
SSegWr( 0x6C ,  0)
SSegWr( 0x6E ,  0)' right-most display

sleep ( 1 * 1000) ' wait for 1 second
' display  "HELP"
SSegWr( 0x68 ,  0b01110110)' left-most display
SSegWr( 0x6A ,  0b01111001)
SSegWr( 0x6C ,  0b00111000)
SSegWr( 0x6E ,  0b01110011)' right-most display

sleep ( 5 * 1000) ' wait for 5 seconds
' display  "1.234"
SSegWr( 0x68 ,  0b10000110)' left-most display, most significant bit=1=decimal point
SSegWr( 0x6A ,  0b01011011)
SSegWr( 0x6C ,  0b01001111)
SSegWr( 0x6E ,  0b01100110)' right-most display
 
sleep ( 5 * 1000) ' wait for 5 seconds
' display   " End"
SSegWr( 0x68 ,  0 )' left-most display
SSegWr( 0x6A ,  0b01111001)
SSegWr( 0x6C ,  0b01010100)
SSegWr( 0x6E ,  0b01011110)' right-most display