0.3.7 MCP4725

libraries/MCP4725/CHANGELOG.md

@@ -5,13 +5,19 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.3.7] - 2023-08-25
+- fix #27 - support for multiple MCP4725
+  - add two examples.
+- update readme.md
+- minor edits
+
+
 ## [0.3.6] - 2023-07-19
 - fix #25 - buffer overflow in examples
 - update keywords.txt
-- moved code to .cpp
+- moved code to MCP4725.cpp
 - minor edits
 
-
 ## [0.3.5] - 2023-01-17
 - update GitHub actions
 - update license

libraries/MCP4725/MCP4725.cpp

@@ -2,10 +2,8 @@
 //    FILE: MCP4725.cpp
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Arduino library for 12 bit I2C DAC - MCP4725
-// VERSION: 0.3.6
+// VERSION: 0.3.7
 //     URL: https://github.com/RobTillaart/MCP4725
-//
-//  HISTORY see changelog.md
 
 
 #include "MCP4725.h"
@@ -31,6 +29,7 @@ MCP4725::MCP4725(const uint8_t deviceAddress, TwoWire *wire)
 
 
 #if defined(ESP8266) || defined(ESP32)
+
 bool MCP4725::begin(const uint8_t dataPin, const uint8_t clockPin)
 {
   _wire  = &Wire;
@@ -48,8 +47,10 @@ bool MCP4725::begin(const uint8_t dataPin, const uint8_t clockPin)
   }
   return false;
 }
+
 #endif
 
+
 #if defined (ARDUINO_ARCH_RP2040)
 
 bool MCP4725::begin(int sda, int scl)
@@ -129,6 +130,17 @@ int MCP4725::writeDAC(const uint16_t value, const bool EEPROM)
 }
 
 
+//  ready checks if the last write to EEPROM has been written.
+//  until ready all writes to the MCP4725 are ignored!
+bool MCP4725::ready()
+{
+  yield();
+  uint8_t buffer[1];
+  _readRegister(buffer, 1);
+  return ((buffer[0] & 0x80) > 0);
+}
+
+
 uint16_t MCP4725::readDAC()
 {
   while(!ready());
@@ -181,7 +193,7 @@ uint8_t MCP4725::readPowerDownModeEEPROM()
 
 uint8_t MCP4725::readPowerDownModeDAC()
 {
-  while(!ready());  // TODO needed?
+  while(!ready());  //  TODO needed?
   uint8_t buffer[1];
   _readRegister(buffer, 1);
   uint8_t value = (buffer[0] >> 1) & 0x03;
@@ -195,7 +207,7 @@ uint8_t MCP4725::readPowerDownModeDAC()
 int MCP4725::powerOnReset()
 {
   int rv = _generalCall(MCP4725_GC_RESET);
-  _lastValue = readDAC(); // update cache to actual value;
+  _lastValue = readDAC(); //  update cache to actual value;
   return rv;
 }
 
@@ -206,7 +218,7 @@ int MCP4725::powerOnReset()
 int MCP4725::powerOnWakeUp()
 {
   int rv = _generalCall(MCP4725_GC_WAKEUP);
-  _powerDownMode = readPowerDownModeDAC();  // update to actual value;
+  _powerDownMode = readPowerDownModeDAC();  //  update to actual value;
   return rv;
 }
 
@@ -215,7 +227,7 @@ int MCP4725::powerOnWakeUp()
 int MCP4725::_writeFastMode(const uint16_t value)
 {
   uint8_t l = value & 0xFF;
-  uint8_t h = ((value / 256) & 0x0F);  // set C0 = C1 = 0, no PDmode
+  uint8_t h = ((value / 256) & 0x0F);  //  set C0 = C1 = 0, no PDmode
   h = h | (_powerDownMode << 4);
 
   _wire->beginTransmission(_deviceAddress);
@@ -225,17 +237,6 @@ int MCP4725::_writeFastMode(const uint16_t value)
 }
 
 
-//  ready checks if the last write to EEPROM has been written.
-//  until ready all writes to the MCP4725 are ignored!
-bool MCP4725::ready()
-{
-  yield();
-  uint8_t buffer[1];
-  _readRegister(buffer, 1);
-  return ((buffer[0] & 0x80) > 0);
-}
-
-
 //  PAGE 19 DATASHEET
 //  reg = MCP4725_DAC | MCP4725_EEPROM
 int MCP4725::_writeRegisterMode(const uint16_t value, uint8_t reg)
@@ -261,9 +262,9 @@ uint8_t MCP4725::_readRegister(uint8_t* buffer, const uint8_t length)
 {
   _wire->beginTransmission(_deviceAddress);
   int rv = _wire->endTransmission();
-  if (rv != 0) return 0;  // error
+  if (rv != 0) return 0;  //  error
 
-  //  readbytes will always be equal or smaller to length
+  //  readBytes will always be equal or smaller to length
   uint8_t readBytes = _wire->requestFrom(_deviceAddress, length);
   uint8_t cnt = 0;
   while (cnt < readBytes)
@@ -277,7 +278,7 @@ uint8_t MCP4725::_readRegister(uint8_t* buffer, const uint8_t length)
 //  name comes from datasheet
 int MCP4725::_generalCall(const uint8_t gc)
 {
-  _wire->beginTransmission(0);  // _deviceAddress
+  _wire->beginTransmission(0);  //  _deviceAddress
   _wire->write(gc);
   return _wire->endTransmission();
 }

libraries/MCP4725/MCP4725.h

@@ -3,7 +3,7 @@
 //    FILE: MCP4725.h
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Arduino library for 12 bit I2C DAC - MCP4725
-// VERSION: 0.3.6
+// VERSION: 0.3.7
 //     URL: https://github.com/RobTillaart/MCP4725
 //
 
@@ -12,7 +12,7 @@
 #include "Arduino.h"
 
 
-#define MCP4725_VERSION         (F("0.3.6"))
+#define MCP4725_VERSION         (F("0.3.7"))
 
 
 //  CONSTANTS
@@ -41,7 +41,9 @@ public:
   explicit MCP4725(const uint8_t deviceAddress, TwoWire *wire = &Wire);
 
 #if defined(ESP8266) || defined(ESP32)
+
   bool     begin(const uint8_t dataPin, const uint8_t clockPin);
+
 #endif
 
 #if defined (ARDUINO_ARCH_RP2040)
@@ -60,16 +62,22 @@ public:
   uint16_t getValue();
 
 
-  //  0..100.0% - no input check.
+  //  0..100.0% - input checked.
+  //  will set the closest integer value in range 0..4095
   int      setPercentage(float percentage = 0);
+  //  due to rounding the returned value can differ slightly.
   float    getPercentage();
 
 
+  //  unfortunately it is not possible to write a different value
+  //  to the DAC and EEPROM simultaneously or write EEPROM only.
   int      writeDAC(const uint16_t value, const bool EEPROM = false);
+  //  ready checks if the last write to EEPROM has been written.
+  //  until ready all writes to the MCP4725 are ignored!
   bool     ready();
   uint16_t readDAC();
   uint16_t readEEPROM();
-  uint32_t getLastWriteEEPROM();
+  uint32_t getLastWriteEEPROM();  //  returns timestamp
 
 
   //  experimental

libraries/MCP4725/README.md

@@ -2,8 +2,11 @@
 [![Arduino CI](https://github.com/RobTillaart/MCP4725/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
 [![Arduino-lint](https://github.com/RobTillaart/MCP4725/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/MCP4725/actions/workflows/arduino-lint.yml)
 [![JSON check](https://github.com/RobTillaart/MCP4725/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/MCP4725/actions/workflows/jsoncheck.yml)
+[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/MCP4725.svg)](https://github.com/RobTillaart/MCP4725/issues)
+
 [![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/MCP4725/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RobTillaart/MCP4725.svg?maxAge=3600)](https://github.com/RobTillaart/MCP4725/releases)
+[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/MCP4725.svg)](https://registry.platformio.org/libraries/robtillaart/MCP4725)
 
 
 # MCP4725
@@ -23,6 +26,10 @@ of 2.7V .. 5.5V. Check datasheet for the details.
 
 ## Interface
 
+```cpp
+#include "MCP4725.h"
+```
+
 ### Constructor
 
 - **MCP4725(uint8_t deviceAddress, TwoWire \*wire = &Wire)** Constructor, needs I2C address, optional set Wire bus
@@ -32,7 +39,7 @@ Returns true if deviceAddress can be found on the I2C bus.
 - **bool isConnected()** returns true if device (address) can be seen on the I2C bus.
 
 
-### base
+### Base
 
 - **int setValue(uint16_t value = 0)** value = 0 .. 4095.  
 Uses writeFastMode and does not write to EEPROM.
@@ -114,9 +121,44 @@ Check RP2040 Pinout for compatible pins.
 When Wire1 is used, it needs to be specified in the constructor with "&Wire1"
 
 
-## Operation
+## Multi devices on one I2C bus
 
-See examples
+Normal one can have 1 to 8 MCP4725 on a I2C bus. This depends on the right
+choice of devices as 2 address bits are hard coded in the device. 
+See paragraph 7.2 datasheet + address notes section above.
+
+But one cannot always order the right devices.
+Especially breakout boards often have the same address-range.
+
+
+#### TCA9548 I2C multiplexer
+
+Use an I2C multiplexer to create multiple "I2C channels" which allows then 
+up to 8 devices per channel. Selecting the right devices includes setting 
+the I2C multiplexer to the right channel to address the right device. 
+This implies access is a bit slower and uses more code.
+
+One (TCA9548) multiplexer allows one to control up to 64 MCP4725's.
+
+- https://github.com/RobTillaart/TCA9548
+
+Note that other multiplexers do exist.
+
+
+#### Use A0 address pin as a SELECT pin
+
+(Experimental)  
+Need to do more tests to see how this solution behaves in practice.  
+Verified to work - see https://forum.arduino.cc/t/using-digital-pins-to-control-two-mcp4725-modules/1161482/7.
+
+The assumption here is that the devices are all from the same address range.
+
+You can control multiple MCP4725 over the hardware I2C bus with an extra IO pin per device.
+- Connect the address pin of every MCP4725 to an IO pin which will work as a **SELECT** pin.
+- Keep all IO pins **LOW** so the all have effectively the same address == 0x60.
+- To select a specific MCP4725 you set the related IO pin to **HIGH** and that one will have address == 0x61.
+- Now you can access and control the associated MCP4725 with address 0x61.
+- See **mcp4725_multiple.ino** and **mcp4725_multiple_minimal.ino**
 
 
 ## Future
@@ -128,9 +170,18 @@ See examples
 #### Should
 
 - test the powerDown modes / functions.
+- test A0 (address bit) as SELECT pin.
 
 #### Could
 
 - extend unit tests
 
 
+## Support
+
+If you appreciate my libraries, you can support the development and maintenance.
+Improve the quality of the libraries by providing issues and Pull Requests, or
+donate through PayPal or GitHub sponsors.
+
+Thank you,
+

libraries/MCP4725/examples/mcp4725_multiple/mcp4725_multiple.ino

@@ -0,0 +1,92 @@
+//
+//    FILE: mcp4725_multiple.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: test MCP4725 lib
+//     URL: https://github.com/RobTillaart/MCP4725
+//
+//  simple example to control more than 2 devices over
+//  a single I2C bus without multiplexer.
+//  The A0 address pin is used as a SELECT pin.
+//
+//  Every MCP device has its own object and can be 
+//  accessed accordingly.
+//
+//  To be tested / confirmed working with hardware.
+
+
+#include "Wire.h"
+#include "MCP4725.h"
+
+//  assume the 4 devices have the same A1 and A2
+//  hard-coded address bits. (par 7.2 datasheet)
+//  we will access all devices with as 0x63.
+MCP4725 MCP0(0x63);
+MCP4725 MCP1(0x63);
+MCP4725 MCP2(0x63);
+MCP4725 MCP3(0x63);
+
+//  connect the select pins to the A0 pins
+//  of the four MCP4725's
+uint8_t selectPin[4] = { 4, 5, 6, 7 };
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("MCP4725_VERSION: ");
+  Serial.println(MCP4725_VERSION);
+
+  for (int i = 0; i < 4; i++)
+  {
+    pinMode(selectPin[i], OUTPUT);
+    digitalWrite(selectPin[i], LOW);
+  }
+
+  select(0);
+  MCP0.begin();
+  select(1);
+  MCP1.begin();
+  select(2);
+  MCP2.begin();
+  select(3);
+  MCP3.begin();
+}
+
+
+
+void select(uint8_t nr)
+{
+  for (int i = 0; i < 4; i++)
+  {
+    if (i != nr) digitalWrite(selectPin[i], LOW);
+    else         digitalWrite(selectPin[i], HIGH);
+  }
+}
+
+
+
+void loop()
+{
+  int x = analogRead(A0);  //  to create an output value.
+
+  //  select one DAC and set the value.
+  select(0);
+  MCP0.setValue(x);
+  delay(250);
+
+  select(1);
+  MCP1.setValue(x * 2);
+  delay(250);
+
+  select(2);
+  MCP2.setValue(x * 3);
+  delay(250);
+
+  select(3);
+  MCP3.setValue(x * 4);
+  delay(250);  
+}
+
+
+//  -- END OF FILE --

libraries/MCP4725/examples/mcp4725_multiple_minimal/mcp4725_multiple_minimal.ino

@@ -0,0 +1,84 @@
+//
+//    FILE: mcp4725_multiple_minimal.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: test MCP4725 lib
+//     URL: https://github.com/RobTillaart/MCP4725
+//
+//  simple example to control more than 2 devices over
+//  a single I2C bus without multiplexer.
+//  The A0 address pin is used as a SELECT pin.
+//
+//  One MCP4725 object is used to control 4 different devices.
+//  drawback is that you can only read back the last write.
+//
+//  To be tested / confirmed working with hardware.
+
+
+#include "Wire.h"
+#include "MCP4725.h"
+
+//  assume the 4 devices have the same A1 and A2
+//  hard-coded address bits. (par 7.2 datasheet)
+//  we will access all devices with as 0x63.
+MCP4725 MCP(0x63);  //  0x62 or 0x63
+
+
+//  connect the select pins to the A0 pins
+//  of the four MCP4725's
+uint8_t selectPin[4] = { 4, 5, 6, 7 };
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("MCP4725_VERSION: ");
+  Serial.println(MCP4725_VERSION);
+
+  for (int i = 0; i < 4; i++)
+  {
+    pinMode(selectPin[i], OUTPUT);
+    digitalWrite(selectPin[i], LOW);
+  }
+
+  select(0);
+  MCP.begin();
+}
+
+
+
+void select(uint8_t nr)
+{
+  for (int i = 0; i < 4; i++)
+  {
+    if (i != nr) digitalWrite(selectPin[i], LOW);
+    else         digitalWrite(selectPin[i], HIGH);
+  }
+}
+
+
+
+void loop()
+{
+  int x = analogRead(A0);  //  to create an output value.
+
+  //  select one DAC and set the value.
+  select(0);
+  MCP.setValue(x);
+  delay(250);
+
+  select(1);
+  MCP.setValue(x * 2);
+  delay(250);
+
+  select(2);
+  MCP.setValue(x * 3);
+  delay(250);
+
+  select(3);
+  MCP.setValue(x * 4);
+  delay(250);
+}
+
+
+//  -- END OF FILE --

libraries/MCP4725/library.json

@@ -15,9 +15,9 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MCP4725.git"
   },
-  "version": "0.3.6",
+  "version": "0.3.7",
   "license": "MIT",
-  "frameworks": "arduino",
+  "frameworks": "*",
   "platforms": "*",
   "headers": "MCP4725.h"
 }

libraries/MCP4725/library.properties

@@ -1,5 +1,5 @@
 name=MCP4725
-version=0.3.6
+version=0.3.7
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for 12 bit I2C DAC - MCP4725