Merge pull request #14 from adafruit/busio

Busio

Author: ladyada

Adafruit_MCP23008.cpp

@@ -22,74 +22,59 @@
  * BSD license, all text above must be included in any redistribution
  */
 
-#if ARDUINO >= 100
-#include "Arduino.h"
-#else
-#include "WProgram.h"
-#endif
-#ifdef __AVR_ATtiny85__
-#include <TinyWireM.h>
-#define Wire TinyWireM
-#else
-#include <Wire.h>
-#endif
-
-#ifdef __AVR
-#include <avr/pgmspace.h>
-#elif defined(ESP8266)
-#include <pgmspace.h>
-#endif
 #include "Adafruit_MCP23008.h"
 
-////////////////////////////////////////////////////////////////////////////////
-// RTC_DS1307 implementation
+///////////////////////////////////////////////////////////////////////////////
 
-void Adafruit_MCP23008::begin(uint8_t addr) {
-  if (addr > 7) {
-    addr = 7;
+/*!
+ * @brief Begins the i2c connection using specified address
+ * @param addr i2c address of the MCP23008, defaults to 0x20
+ * @param wire TwoWire interface, defaults to &Wire
+ * @returns False if failed to find device at address
+ */
+bool Adafruit_MCP23008::begin(uint8_t addr, TwoWire *wire) {
+  if ((addr >= 0x20) && (addr <= 0x27)) {
+    _i2caddr = addr;
+  } else if (addr <= 0x07) {
+    _i2caddr = 0x20 + addr;
+  } else {
+    _i2caddr = 0x27;
   }
-  i2caddr = addr;
 
-  Wire.begin();
+  if (i2c_dev) {
+    delete i2c_dev; // remove old interface
+  }
+
+  i2c_dev = new Adafruit_I2CDevice(_i2caddr, wire);
+
+  if (!i2c_dev->begin()) {
+    return false;
+  }
 
   // set defaults!
-  Wire.beginTransmission(MCP23008_ADDRESS | i2caddr);
-#if ARDUINO >= 100
-  Wire.write((byte)MCP23008_IODIR);
-  Wire.write((byte)0xFF); // all inputs
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-  Wire.write((byte)0x00);
-#else
-  Wire.send(MCP23008_IODIR);
-  Wire.send(0xFF); // all inputs
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-  Wire.send(0x00);
-#endif
-  Wire.endTransmission();
-}
+  uint8_t buf[] = {MCP23008_IODIR,
+                   0xFF, // all inputs
+                   0x00,           0x00, 0x00, 0x00, 0x00,
+                   0x00,           0x00, 0x00, 0x00};
+  if (!i2c_dev->write(buf, 10)) {
+    return false;
+  }
 
-void Adafruit_MCP23008::begin(void) { begin(0); }
+  return true;
+}
 
-void Adafruit_MCP23008::pinMode(uint8_t p, uint8_t d) {
+/*!
+ * @brief Sets the pin mode
+ * @param p Mode to set
+ * @param d Pin to set the mode to
+ * @returns True on success, False on bad input or I2C failure
+ */
+bool Adafruit_MCP23008::pinMode(uint8_t p, uint8_t d) {
   uint8_t iodir;
 
   // only 8 bits!
   if (p > 7)
-    return;
+    return false;
 
   iodir = read8(MCP23008_IODIR);
 
@@ -101,22 +86,39 @@ void Adafruit_MCP23008::pinMode(uint8_t p, uint8_t d) {
   }
 
   // write the new IODIR
-  write8(MCP23008_IODIR, iodir);
+  return write8(MCP23008_IODIR, iodir);
 }
 
+/*!
+ * @brief Reads the current GPIO input
+ * @return Returns the current GPIO input
+ */
 uint8_t Adafruit_MCP23008::readGPIO(void) {
   // read the current GPIO input
   return read8(MCP23008_GPIO);
 }
 
-void Adafruit_MCP23008::writeGPIO(uint8_t gpio) { write8(MCP23008_GPIO, gpio); }
+/*!
+ * @brief Writes to the GPIO
+ * @param gpio what to write
+ * @returns True on success, False on bad input or I2C failure
+ */
+bool Adafruit_MCP23008::writeGPIO(uint8_t gpio) {
+  return write8(MCP23008_GPIO, gpio);
+}
 
-void Adafruit_MCP23008::digitalWrite(uint8_t p, uint8_t d) {
+/*!
+ * @brief Sets the pin and direction
+ * @param p Pin to set
+ * @param d Direction to set the pin
+ * @returns True on success, False on bad input or I2C failure
+ */
+bool Adafruit_MCP23008::digitalWrite(uint8_t p, uint8_t d) {
   uint8_t gpio;
 
   // only 8 bits!
   if (p > 7)
-    return;
+    return false;
 
   // read the current GPIO output latches
   gpio = readGPIO();
@@ -129,15 +131,21 @@ void Adafruit_MCP23008::digitalWrite(uint8_t p, uint8_t d) {
   }
 
   // write the new GPIO
-  writeGPIO(gpio);
+  return writeGPIO(gpio);
 }
 
-void Adafruit_MCP23008::pullUp(uint8_t p, uint8_t d) {
+/*!
+ * @brief Sets pull-up resistor on specified pin
+ * @param p Pin to set
+ * @param d Direction to set the pin
+ * @returns True on success, False on bad input or I2C failure
+ */
+bool Adafruit_MCP23008::pullUp(uint8_t p, uint8_t d) {
   uint8_t gppu;
 
   // only 8 bits!
   if (p > 7)
-    return;
+    return false;
 
   gppu = read8(MCP23008_GPPU);
   // set the pin and direction
@@ -147,9 +155,14 @@ void Adafruit_MCP23008::pullUp(uint8_t p, uint8_t d) {
     gppu &= ~(1 << p);
   }
   // write the new GPIO
-  write8(MCP23008_GPPU, gppu);
+  return write8(MCP23008_GPPU, gppu);
 }
 
+/*!
+ * @brief Reads the status of a gpio pin
+ * @param p Pin to read
+ * @return Returns the current gpio
+ */
 uint8_t Adafruit_MCP23008::digitalRead(uint8_t p) {
   // only 8 bits!
   if (p > 7)
@@ -160,30 +173,12 @@ uint8_t Adafruit_MCP23008::digitalRead(uint8_t p) {
 }
 
 uint8_t Adafruit_MCP23008::read8(uint8_t addr) {
-  Wire.beginTransmission(MCP23008_ADDRESS | i2caddr);
-#if ARDUINO >= 100
-  Wire.write((byte)addr);
-#else
-  Wire.send(addr);
-#endif
-  Wire.endTransmission();
-  Wire.requestFrom(MCP23008_ADDRESS | i2caddr, 1);
-
-#if ARDUINO >= 100
-  return Wire.read();
-#else
-  return Wire.receive();
-#endif
+  Adafruit_BusIO_Register reg = Adafruit_BusIO_Register(i2c_dev, addr, 1);
+  return reg.read();
 }
 
-void Adafruit_MCP23008::write8(uint8_t addr, uint8_t data) {
-  Wire.beginTransmission(MCP23008_ADDRESS | i2caddr);
-#if ARDUINO >= 100
-  Wire.write((byte)addr);
-  Wire.write((byte)data);
-#else
-  Wire.send(addr);
-  Wire.send(data);
-#endif
-  Wire.endTransmission();
+bool Adafruit_MCP23008::write8(uint8_t addr, uint8_t data) {
+  Adafruit_BusIO_Register reg = Adafruit_BusIO_Register(i2c_dev, addr, 1);
+
+  return reg.write(data);
 }

Adafruit_MCP23008.h

@@ -4,68 +4,32 @@
 
 #ifndef _ADAFRUIT_MCP23008_H
 #define _ADAFRUIT_MCP23008_H
-// Don't forget the Wire library
-#ifdef __AVR_ATtiny85__
-#include <TinyWireM.h>
-#else
-#include <Wire.h>
-#endif
+
+#include <Adafruit_BusIO_Register.h>
+#include <Adafruit_I2CDevice.h>
+#include <Arduino.h>
 
 /*!
  * @brief Class that stores state and functions for interacting with MCP23008
  * chip
  */
 class Adafruit_MCP23008 {
 public:
-  /*!
-   * @brief Begins the i2c connection using specified address
-   * @param addr i2c address of the MCP23008
-   */
-  void begin(uint8_t addr);
-  /*!
-   * @brief Begins the i2c connection using default address
-   */
-  void begin(void);
+  bool begin(uint8_t addr = 0x20, TwoWire *wire = &Wire);
 
-  /*!
-   * @brief Sets the pin mode
-   * @param p Mode to set
-   * @param d Pin to set the mode to
-   */
-  void pinMode(uint8_t p, uint8_t d);
-  /*!
-   * @brief Sets the pin and direction
-   * @param p Pin to set
-   * @param d Direction to set the pin
-   */
-  void digitalWrite(uint8_t p, uint8_t d);
-  /*!
-   * @brief Sets pull-up resistor on specified pin
-   * @param p Pin to set
-   * @param d Direction to set the pin
-   */
-  void pullUp(uint8_t p, uint8_t d);
-  /*!
-   * @brief Reads the status of a gpio pin
-   * @param p Pin to read
-   * @return Returns the current gpio
-   */
+  bool pinMode(uint8_t p, uint8_t d);
+  bool digitalWrite(uint8_t p, uint8_t d);
+  bool pullUp(uint8_t p, uint8_t d);
   uint8_t digitalRead(uint8_t p);
-  /*!
-   * @brief Reads the current GPIO input
-   * @return Returns the current GPIO input
-   */
   uint8_t readGPIO(void);
-  /*!
-   * @brief Writes to the GPIO
-   * @param gpio what to write
-   */
-  void writeGPIO(uint8_t);
+  bool writeGPIO(uint8_t);
 
 private:
-  uint8_t i2caddr;
+  Adafruit_I2CDevice *i2c_dev = NULL; ///< Pointer to I2C bus interface
+
+  uint8_t _i2caddr;
   uint8_t read8(uint8_t addr);
-  void write8(uint8_t addr, uint8_t data);
+  bool write8(uint8_t addr, uint8_t data);
 };
 
 #define MCP23008_ADDRESS 0x20 //!< MCP23008 serial address

README.md

@@ -4,6 +4,8 @@ To download, click "Download Source" in the top right corner. Then install as in
 --> http://www.ladyada.net/library/arduino/libraries.html
 in a folder called Adafruit_MCP23008.
 
+You will also need the Adafruit BusIO library: https://github.com/adafruit/Adafruit_BusIO
+
 This is very much beta, it seems to work fine but its not optimized and doesn't currently suport the interrupt capability of the chip
 
 Currently it can do: setting pin directions, inputs and outputs and turning on/off the pull-up resistors

library.properties

@@ -1,9 +1,10 @@
 name=Adafruit MCP23008 library
-version=1.1.0
+version=2.0.0
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=Arduino Library for the MCP23008 (and '9) I2C I/O expander
 paragraph=Arduino Library for the MCP23008 (and '9) I2C I/O expander
 category=Signal Input/Output
 url=https://github.com/adafruit/Adafruit-MCP23008-library
 architectures=*
+depends=Adafruit BusIO