Cannot drive I2C Oled :(

[Alberto]

Hi all, I did use the Timc code to drive a 0.96 '' oled display and it works fine (thank you Timc)
The only doubt now I have is the warning message I get compiling the code:

"ASM WARNING Argument out of range. Last significant bits used. (0) : Warninig [202]"

What does it mean?
How can I remove it?

Alberto

[wellyboot]

I bought a OLED display on ebay saying it had a SSD1306 chip, trying running some code from here and I got a display full of noise

Turns out it has SH1106 driver

I modified the code here to work with it on 18F877
this draws a box around the display


<code>

'OLED driver 16F877
'SH1106 driver
'NOT SSD1306

'==========================MCU SETUP============================================
Include "modedefs.bas"

DEFINE OSC 8


ADCON0=0
ADCON1=7
TRISA=%00111111
TRISB=%00000001
TRISC=0
TRISD=0
TRISE=0
PORTC=$FF

'==============================Variables========== =============================

I2CDevice var byte
SCL var PortC.3 ' I2C Clock PortC.3
SDA var PortC.4 ' I2C Data PortC.4
DC VAR byte' "DATA OR COMMAND", $40=DATA; $0=COMMAND
LCD_DATA VAR BYTE
COM VAR BYTE' COMMAND


I VAR BYTE
J VAR BYTE
X VAR BYTE' LCD Column POSITION (0 TO 127)
Y VAR BYTE'LCD Line POSITION FOR PAGE MODE(0 TO 7)
Xlow VAR BYTE 'Low 4 bits of X
Xhigh VAR BYTE 'High 4 bits of X
CLEAR
'================================================= ============================
I2CDevice = $78 ' Display = $78,
PAUSE 500
'=========================lcd initialization====================================
DC = 0
INIT:
I2CWrite SDA,SCL,I2CDevice,[DC,$AE]'Display Off
pause 10
I2CWrite SDA,SCL,I2CDevice,[DC,$D3,$00]' Set offset to 0
I2CWrite SDA,SCL,I2CDevice,[DC,$40]' Set display start line 0
I2CWrite SDA,SCL,I2CDevice,[DC,$8D,$14]' Set Charge Pump Internal, usually needed
'I2CWrite SDA,SCL,I2CDevice,[DC,$20,$10]' Page adressing mode
I2CWrite SDA,SCL,I2CDevice,[DC,$A1]' set column 0 as start
i2cwrite sda,scl,I2CDevice,[DC,$C8]'
I2CWrite SDA,SCL,I2CDevice,[DC,$DA,$12]' set COM pins = 128x64=$12 128x32=$02'
I2CWrite SDA,SCL,I2CDevice,[DC,$81,$01]' Set contrast to low
I2CWrite SDA,SCL,I2CDevice,[DC,$A4]' display on continue
I2CWrite SDA,SCL,I2CDevice,[DC,$A6]' $A6=NORMAL MODE;$A7=INVERSE MODE

I2CWrite SDA,SCL,I2CDevice,[DC,$AF]'Display On
pause 500




'================================================= ==============================
GOSUB CLEAR_LCD
pause 500



MAIN:

gosub CLEAR_LCD
pause 1000
gosub BOX1
pause 1000

GOTO MAIN

'======================Send data============================================== =
SEND_DATA:
DC=$40
I2CWrite SDA,SCL,I2CDevice,[DC,LCD_DATA]
RETURN
'================================================= ==============================
'======================Send Command=========================================== ==
SEND_COMMAND:
DC=0
I2CWrite SDA,SCL,I2CDevice,[DC,COM]
RETURN
'================================================= ==============================

'==============================clear lcd========================================
CLEAR_LCD:
X=2
Y=0
LCD_DATA=$00
'Send 0 to every column in every line
FOR Y=0 TO 7
gosub SET_XY
FOR I=0 TO 127
GOSUB SEND_DATA
NEXT I
NEXT Y
RETURN

'================================================= ==============================
BOX1:
FOR Y = 0 TO 7
X=2
GOSUB SET_XY
LCD_DATA=%11111111
GOSUB SEND_DATA
X=129
GOSUB SET_XY
GOSUB SEND_DATA
NEXT Y
FOR X = 3 TO 128
Y=0
GOSUB SET_XY
LCD_DATA=%00000001
GOSUB SEND_DATA
Y=7
GOSUB SET_XY
LCD_DATA=%10000000
GOSUB SEND_DATA
NEXT


RETURN

'===========================================SET X AND Y=========================
SET_XY:
COM = $B0
COM = COM + Y '<<<--- SET PAGE ADDRESS %1011DDDD
GOSUB SEND_COMMAND

Xhigh = X >> 4
Xlow = X &$0F
COM=Xlow '<<<--- SET COL ADDRESS LOW bits %0000DDDD
GOSUB SEND_COMMAND
Xhigh.4 = 1
COM = Xhigh '<<<--- SET COL ADDRESS HIGH bits %0001DDDD
GOSUB SEND_COMMAND

RETURN
'================================================= ==============================


END

</code>

[Art]

Probably this:

chartmp = charset - 295

char temp is a byte who’s maximum value is 255.
It will probably also break it if it was working, to fix it,
you’d probably have to rotate the values in the lookup table by some amount.

Hi all, I did use the Timc code to drive a 0.96 '' oled display and it works fine (thank you Timc)
The only doubt now I have is the warning message I get compiling the code:

"ASM WARNING Argument out of range. Last significant bits used. (0) : Warninig [202]"

What does it mean?
How can I remove it?

Alberto