Arduino class for I2C digital potentiometer AD5241 AD5242 AD5280 AD5282.
The AD5241, AD5242, AD5280 and AD5282 are digital potentiometers. The AD5241/80 has one, the AD5242/82 has two potentiometers. Both types have two output lines O1 and O2.
The main difference in the AD524x and AD528x series is the resistance. See the table below.
The AD5280/82 is compatible with AD5241/42 (based upon datasheet compare). The library provides separate classes for the AD5280/82 however these are not tested with actual hardware yet. Please let me know if you get the AD5280/82 classes working.
| device | channels | steps | ranges KΩ |
|---|---|---|---|
| AD5241 | 1 | 256 | 10, 100, 1000 |
| AD5242 | 2 | 256 | 10, 100, 1000 |
| AD5280 | 1 | 256 | 20, 50, 200 |
| AD5282 | 2 | 256 | 20, 50, 200 |
An important property of the devices is that they defaults to their mid position at startup.
The library defines AD524X_MIDPOINT == 127. To be used to set to defined mid-point.
The ESP32 specific begin(sda, scl) is removed. The user has to call Wire.begin() or equivalent himself before calling begin().
- https://github.com/RobTillaart/AD520x
- https://github.com/RobTillaart/AD524X
- https://github.com/RobTillaart/AD5245
- https://github.com/RobTillaart/AD5248 (also AD5243)
- https://github.com/RobTillaart/AD5144A
- https://github.com/RobTillaart/AD5263
- https://github.com/RobTillaart/X9C10X
If you find compatible devices please let me know.
The AD524X has two address lines to configure the I2C address. 0x2C - 0x2F
| Addr(dec) | Addr(Hex) | AD1 | AD0 |
|---|---|---|---|
| 44 | 0x2C | GND | GND |
| 45 | 0x2D | GND | +5V |
| 46 | 0x2E | +5V | GND |
| 47 | 0x2F | +5V | +5V |
#include "AD524X.h"The library has a number of functions which are all quite straightforward. One can get / set the value of (both) the potentiometer(s), and the O1 and O2 output lines.
- AD524X(uint8_t address, TwoWire *wire = &Wire) constructor base class, creates an instance with 2 potentiometer. This class does not distinguish between AD5241/42/80/82. The developer is responsible for handling this correctly.
- AD5241(uint8_t address, TwoWire *wire = &Wire) create an instance with 1 potentiometer.
- AD5242(uint8_t address, TwoWire *wire = &Wire) create an instance with 2 potentiometer.
- AD5280(uint8_t address, TwoWire *wire = &Wire) create an instance with 1 potentiometer.
- AD5282(uint8_t address, TwoWire *wire = &Wire) create an instance with 2 potentiometer.
- bool begin() initialization of the object. Note the user must call wire.begin() or equivalent before calling begin().
- bool isConnected() See if the address set in constructor is on the I2C bus.
- uint8_t getAddress() returns address set in constructor, convenience.
- uint8_t write(uint8_t rdac, uint8_t value) set channel rdac 0/1 to value 0..255.
- uint8_t write(uint8_t rdac, uint8_t value, uint8_t O1, uint8_t O2) idem + set output lines O1 and O2 too.
- uint8_t read(uint8_t rdac) read back set value.
- uint8_t setO1(uint8_t value = HIGH) value = HIGH (default) or LOW.
- uint8_t setO2(uint8_t value = HIGH) value = HIGH (default) or LOW.
- uint8_t getO1() read back O1 line.
- uint8_t getO2() read back O2 line.
- uint8_t zeroAll() sets potentiometer's to 0 and I/O to LOW.
- uint8_t reset() sets potentiometer's to midpoint == 127 and I/O to LOW. (startup default)
- uint8_t midScaleReset(uint8_t rdac) resets one potentiometer to midpoint == 127.
- uint8_t readBackRegister() read register back, for debugging.
- uint8_t shutDown() check datasheet, not tested yet, use at own risk.
Since 0.4.1 the library supports writing explicit to port 0 as that is the only port.
- uint8_t write(const uint8_t value) set rdac 0 to value 0..255.
- uint8_t write(const uint8_t value, const uint8_t O1, const uint8_t O2) idem + set output lines O1 and O2 too.
Note that uint8_t write(rdac, value) and uint8_t write(rdac, value, O1, O2) can be called and return AD524X_ERROR if rdac > 0.
| define | value |
|---|---|
| AD524X_OK | 0 |
| AD524X_ERROR | 100 |
- improve documentation.
- verify the working of AD5280 and AD5282.
- improve error handling.
- sync with AD520X library.
- make midpoint 128
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