User manual

425
mikoPascal PRO for dsPIC30/33 and PIC24
MikroElektronika
Library Example
The example demonstrates how to communicate with Port Expander MCP23S17. Note that Port Expander pins A2 A1
A0 are connected to GND so Port Expander Hardware Address is 0.
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program PortExpander;
// Port Expander module connections
var SPExpanderRST : sbit at LATF0_bit;
SPExpanderCS : sbit at LATF1_bit;
SPExpanderRST_Direction : sbit at TRISF0_bit;
SPExpanderCS_Direction : sbit at TRISF1_bit;
// End Port Expander module connections
var counter : word;
begin
ADPCFG := 0xFFFF; // initialize AN pins as digital
TRISB := 0x00;
LATB := 0xFF;
// If Port Expander Library uses SPI1 module
SPI1_Init(); // Initialize SPI module used with PortExpander
Expander_Init(0); // Initialize Port Expander
Expander_Set_DirectionPortA(0, 0x00); // Set Expander’s PORTA to be output
Expander_Set_DirectionPortB(0,0xFF); // Set Expander’s PORTB to be input
Expander_Set_PullUpsPortB(0,0xFF); // Set pull-ups to all of the Expander’s PORTB
pins
while ( TRUE ) do // Endless loop
begin
Expander_Write_PortA(0, counter); // Write i to expander’s PORTA
Inc(counter);
PORTB := Expander_Read_PortB(0); // Read expander’s PORTB and write it to LEDs
Delay_ms(100);
end;
end.