SI570 Class Reference

Create an instance of the SI570 connected to specified I2C pins, with the specified address.

Example:

 #include "mbed.h"
 #include "TextLCD.h"
 #include "SI570.h"
 #include "QEI.h"
 
 TextLCD lcd(p11, p12, p15, p16, p29, p30); // rs, e, d0-d3
 SI570 si570(p9, p10, 0xAA);
 QEI wheel (p5, p6, NC, 360);

 int main() {
     int wp,swp=0;
     float startfreq=7.0;
     float freq;

     while (1) {
         wp =  wheel.getPulses();
         freq=startfreq+wp*0.00001;
         if (swp != wp) {
             si570.set_frequency(freq);
             swp = wp;
         }                
         lcd.locate(0,0);
         lcd.printf("%f MHz", si570.get_frequency());
     }
 }

Parameters:

sda	The I2C data pin
scl	The I2C clock pin
address	The I2C address for this SI570

Definition at line 26 of file SI570.cpp.

Read the current frequency.

get the SI570 registers an calculate the current frequency

Returns:

the current frequency

Definition at line 80 of file SI570.cpp.

Read the current hsdiv.

get the SI570 registers an calculate the current hsdiv

Returns:

the current hsdiv

Definition at line 95 of file SI570.cpp.

Read the current n1.

get the SI570 registers an calculate the current n1

Returns:

the current n1

Definition at line 90 of file SI570.cpp.

Read the current rfreq value.

get the SI570 registers an calculate the current rfreq

Returns:

the current rfreq

Definition at line 85 of file SI570.cpp.

Set a new frequency.

Set the SI570 registers to output frequency When the new frequency is within the 3500 PPM range of the center frequency, hsdiv and n1 needs not to be reprogrammed, resulting in a glitch free transition. For changes larger than 3500 PPM, the process of freezing and unfreezing the DCO will cause the output clock to momentarily stop and start at any arbitrary point during a clock cycle. This process can take up to 10 ms.

Parameters:

frequency

the frequency to set.

Returns:

the current frequency

Definition at line 100 of file SI570.cpp.

Resets the SI570.

Resets and reads the startup configuration from the Si570

Definition at line 34 of file SI570.cpp.