EmbeddedArtists AB / lpc812_exp_lib_PCF8591

Library with PCF8591 support for the experiments for LPC812 MAX

Dependents:   lpc812_exp_solution_analog-in lpc812_exp_solution_7-segment lpc812_exp_solution_7-segment-shift lpc812_exp_solution_pwm ... more

Fork of lpc812_exp_lib_PCF8591 by EmbeddedArtists AB

PCF8591.cpp@4:a7d0ee55d5cd, 2013-11-22 (annotated)

Committer:
embeddedartists
Date:
Fri Nov 22 14:59:28 2013 +0000
Revision:
4:a7d0ee55d5cd
Parent:
2:8371322cbdc2 
Updated docs

Who changed what in which revision?

UserRevisionLine numberNew contents of line
embeddedartists 0:4ee0a6513a17 1 #include "mbed.h"
embeddedartists 0:4ee0a6513a17 2 #include "PCF8591.h"
embeddedartists 0:4ee0a6513a17 3
embeddedartists 0:4ee0a6513a17 4 PCF8591::PCF8591(PinName sda, PinName scl, int i2cAddr) : m_i2c(sda, scl)
embeddedartists 0:4ee0a6513a17 5 {
embeddedartists 2:8371322cbdc2 6 m_i2c.frequency(100000);
embeddedartists 0:4ee0a6513a17 7 m_addr = i2cAddr;
embeddedartists 0:4ee0a6513a17 8 }
embeddedartists 0:4ee0a6513a17 9
embeddedartists 0:4ee0a6513a17 10 int PCF8591::read(AnalogIn port)
embeddedartists 0:4ee0a6513a17 11 {
embeddedartists 2:8371322cbdc2 12 char cmd = (port & 0x3); // read from selected port
embeddedartists 2:8371322cbdc2 13 char data[2];
embeddedartists 0:4ee0a6513a17 14
embeddedartists 0:4ee0a6513a17 15 // select the port
embeddedartists 2:8371322cbdc2 16 m_i2c.start();
embeddedartists 2:8371322cbdc2 17 m_i2c.write(m_addr);
embeddedartists 2:8371322cbdc2 18 m_i2c.write(cmd);
embeddedartists 2:8371322cbdc2 19 m_i2c.stop();
embeddedartists 0:4ee0a6513a17 20
embeddedartists 0:4ee0a6513a17 21 // get the sample
embeddedartists 2:8371322cbdc2 22 m_i2c.start();
embeddedartists 2:8371322cbdc2 23 m_i2c.write(m_addr | 1);
embeddedartists 2:8371322cbdc2 24 data[0] = m_i2c.read(1); // expect ACK
embeddedartists 2:8371322cbdc2 25 data[1] = m_i2c.read(0); // expect NACK
embeddedartists 2:8371322cbdc2 26 m_i2c.stop();
embeddedartists 2:8371322cbdc2 27
embeddedartists 2:8371322cbdc2 28 // data[0] is a dummy byte so ignore it
embeddedartists 2:8371322cbdc2 29 // data[1] is the new value
embeddedartists 2:8371322cbdc2 30 return data[1];
embeddedartists 0:4ee0a6513a17 31 }
embeddedartists 0:4ee0a6513a17 32