Diff: PCA9532.cpp

Revision:

0:0df46cf615c3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9532.cpp	Fri May 07 12:41:06 2010 +0000
@@ -0,0 +1,191 @@
+/* mbed PCF9532 LED Driver Library
+ *
+ * Copyright (c) 2010, cstyles (http://mbed.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#include "PCA9532.h"
+#include "mbed.h"
+
+/*
+ Constructor, pin names for I2C and the I2C addrss of the device
+ */
+PCA9532::PCA9532(PinName scl, PinName sda, int addr)
+        : _i2c(scl, sda) {
+
+    _i2c.frequency(1000000);
+
+    _addr = addr;
+
+}
+
+
+
+
+
+/*
+ Set the period
+ */
+int PCA9532::Period (int channel, float period) {
+
+    char reg = 0;
+    
+    if (channel == 0) {
+       reg = PCA9532_REG_PSC0;
+    } else if (channel == 1) {
+       reg = PCA9532_REG_PSC1;
+    } else {
+        return (1);
+    }
+
+    if (period > 1.0) {
+        period = 255;
+    } else if ( period < 0.0 ) {
+        period = 0;
+    } else {
+        period = 256 * period;
+    }
+
+    _write(reg, period);
+    return(0);
+
+}
+
+
+/*
+ Set the duty cycle
+ */
+int PCA9532::Duty (int channel, float d) {
+
+    char duty = 0;
+    char reg = 0;
+    
+    if (channel == 0) {
+       reg = PCA9532_REG_PWM0;
+    } else if (channel == 1) {
+       reg = PCA9532_REG_PWM1;
+    } else {
+        return (1);
+    }
+
+    if (d > 1.0) {
+        duty = 255;
+    } else if ( d < 0.0 ) {
+        duty = 0;
+    } else {
+        duty = 256 * d;
+    }
+
+    _write(reg, duty);
+    return(0);
+
+}
+
+/*
+ Set each of the LEDs in this mask to the give mode
+ Loop through the mask calling SetLed on each match
+ alt_mode specifies the mode of the non-Matches of SetMode
+ */
+int PCA9532::SetMode (int mask, int mode) {
+    if ( (mode < 0) || (mode > 3) ) {
+        return(1);
+    } else {
+        for (int i=0 ; i < 16 ; i++ ) {
+
+            // if this matches, set the LED to the mode
+            if (mask & (0x1 << i)) {
+                SetLed(i,mode);
+            }
+        }
+    }
+    return(0);
+}
+
+
+
+/*
+ led is in the range 0-15
+ mode is inthe range 0-3
+ */
+int PCA9532::SetLed(int led, int mode) {
+
+    int reg = 0;
+    int offset = (led % 4);
+
+    printf("\nSetLed(%d,%d)\n", led, mode);
+
+    // makesure mode is within bounds
+    if ( (mode < 0) || (mode > 3) ) {
+        printf("Error : Invalid mode supplied\n");
+        return(1);
+    }
+
+    // determine which register this is,
+    if (led < 4) {
+        reg = PCA9532_REG_LS0;
+    } else if ( (led > 3) && (led < 8) ) {
+        reg = PCA9532_REG_LS1;
+    } else if ( (led > 7) && (led < 12) ) {
+        reg = PCA9532_REG_LS2;
+    } else if ( (led > 11) && (led < 16) ) {
+        reg = PCA9532_REG_LS3;
+    } else {
+        return(1);
+    }
+
+    // read the current status of the register
+    char regval = _read(reg);
+
+    // clear the two bit slice at the calculated offset
+    regval &= ~(0x3 << (2 * offset));
+
+    // now OR in the mode, shifted by 2*offset
+    regval |= (mode << (2 * offset));
+
+    // write the new value back
+    _write(reg, regval);
+
+    return(0);
+}
+
+
+
+// private functions for low level IO
+
+void PCA9532::_write(int reg, int data) {
+    char args[2];
+    args[0] = reg;
+    args[1] = data;
+    _i2c.write(_addr, args,2);
+}
+
+int PCA9532::_read(int reg) {
+    char args[2];
+    args[0] = reg;
+    _i2c.write(_addr, args, 1);
+    _i2c.read(_addr, args, 1);
+    return(args[0]);
+}
+
+
+
+
+