Hi,
I want to connect the Varitronix VI-303-DP to the MSP430FG439 MCU.
So far I have done the following:
- Connected R03 to GND
- Left R13, R23 and R33 unconnected
- Connected COM0 from MCU to both COM pins (1 and 40) of the LCD
- Connected Sx to the right LCD pins
- Set the following registers in C code (using IAR):
P5SEL |= (BIT7 | BIT6 | BIT5 | BIT4 | BIT3 | BIT2);
BTCTL = BT_fLCD_DIV256;
LCDCTL = LCDSG0_3 | LCDSTATIC |LCDON;
The first line is probably not necessary for static displays. The second line gives a frequency of 64.5 Hz in my application (verified with oscilloscope) and the third switches on the LCD driver in static mode from S0-S23. I need only 3 digits of the LCD, the rest doesn't matter so those pins are enough.
The problem I have now is that the COM0 line switches between 0.8V and 3.08V and the Sx lines between ~1.4V and ~2.4V. This results in a -1.68V to 1.12V square wave to drive the LCD. But the minimum voltage at which the LCD operates is 3V (or 3.3V). I thought the LCD Driver on the MCU could/should deliver this? Am I doing something wrong? Do I need to connect some other pin to a reference voltage or did I forget to set a bit in a SFR?
Thanks,
Arne
