PICBASIC PLUS LITE Manual - Profe Saul

PICBASIC PLUS CompilerDECLARE FONT_ADDR 0 to 7Set the slave address for the I 2 C eeprom that contains the font.When an external source for the font is used, it may be on any one of8 eeproms attached to the I 2 C bus. So as not to interfere with anyother eeproms attached, the slave address of the eeprom carrying thefont code may be chosen.If the DECLARE is omitted from the program, then address 0 is thedefault slave address of the font eeprom.Important :Because of the complexity involved with interfacing to the graphicLCD, five of the eight stack levels available are used when the PRINTcommand is issued with an external font. Therefore, be aware that ifPRINT is used within a subroutine, you must limit the amount of subroutinenesting that may take place.If an internal font is implemented, then only four stack levels areused.If the default setting of PORTE is used for the LCD’s CS1, CS2, andRW pin connections, then these pins should be set to digital by issuingthe following line of code near the beginning of the program: -ADCON1 = 7‘ Set PORTA and PORTE to all digitalYou will need to refer to the PIC’s datasheet for ADCON1 settings ifPORTA is to be used for analogue inputs.The diagram showsthe connections requiredfor an external font.5 VoltsThe eeprom hasa slave address of 0.If an internal font isused, then theeeprom may beomitted.C110uF0VC20.1uFR14.7k20MHzCrystalC315pFC415pF991131411VDDVDDRC7RC6RC5RC4MCLR RC3RC2RC1RC0PIC16F877RB7RB6RB5RB4RB3RB2OSC1 RB1RB0OSC2VSS12VSS3132RE2RE1RE0RD7RD6RD5RD4RD3RD2RD1RD0RA5RA4RA3RA2RA1RA01098302928272221201926252423181716154039383736353433765432LEDKLEDA202x4.7k-VoutRSTDB75664x128DOT MATRIXGRAPHIC LCDDB6DB5DB4DB3SDASCLDB2VCC24C328VSS4DB1DB05 VoltsWPA0A1A2Contrast47k5 VoltsCopyright Crownhill 2001ENR/WRS7123VoVccGndCS2CS11