Diff: PCA9534.cpp

Revision:

0:fe2b1519a978

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9534.cpp	Wed Apr 02 03:49:20 2014 +0000
@@ -0,0 +1,74 @@
+
+#include "PCA9534.h"
+
+char PCA9534::readRegister(char reg)
+{
+    char msg[2] = {reg, 0};
+    _i2c->write(_address, msg, 1, 1);
+    _i2c->read((_address|1), msg, 1);
+    return msg[0];
+}
+
+int PCA9534::writeRegister(char reg, char val)
+{
+    char msg[] = {reg, val};
+    return _i2c->write(_address, msg, 2);
+}
+
+void PCA9534::irqHandler(void)
+{
+    // IO state change. Figure out what happened. read clears
+}
+
+PCA9534::PCA9534(I2C &i2c, char address, InterruptIn &irq)
+{
+    _i2c = &i2c;
+    _address = (0x40 | (address<<1));
+    _i2c->frequency(400000);
+    _irq = &irq;
+    if (_irq != 0) {
+        _irq->fall(this, &PCA9534::irqHandler);
+    }
+}
+
+int PCA9534::input(char val)
+{
+    return writeRegister(3, val);
+}
+
+int PCA9534::input(BIT_LOC bit)
+{
+    return input((1<<bit));
+}
+
+int PCA9534::output(char val)
+{
+    return writeRegister(3, ~val);
+}
+
+int PCA9534::output(BIT_LOC bit)
+{
+    return output(~(1<<bit));
+}
+
+int PCA9534::read(void)
+{
+    return readRegister(0);
+}
+
+int PCA9534::read(BIT_LOC bit)
+{
+    char val = readRegister(0);
+    return ((val&(1<<bit))==(1<<bit)) ? 1 : 0;
+}
+
+int PCA9534::write(char val)
+{
+    return writeRegister(1, val);
+}
+
+int PCA9534::write(BIT_LOC bit)
+{
+    char val = readRegister(1);
+    return write(val | (1<<bit));
+}