Arduino library for I2C single channel digital rheostat AD5246.
The library is experimental and not tested with hardware yet.
The AD5246 is a single channel digital rheostat which comes in 5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ and can be set in 128 steps.
Indicative step size.
| value | step size |
|---|---|
| 5 kΩ | 39.06 Ω |
| 10 kΩ | 78.13 Ω |
| 50 kΩ | 390.6 Ω |
| 100 kΩ | 781.3 Ω |
An important property is that the device defaults to the mid-scale position at startup. One can use AD5246_MIDPOINT == 64 to reset to the mid-scale position.
Version 0.2.0 introduced a breaking change. You cannot set the pins in begin() any more. This reduces the dependency of processor dependent Wire implementations. The user has to call Wire.begin() and can optionally set the Wire pins before calling begin().
This library is based upon the AD5245 library.
- https://www.analog.com/en/products/ad5246.html
- https://github.com/RobTillaart/AD520x
- https://github.com/RobTillaart/AD524X
- https://github.com/RobTillaart/AD5245
- https://github.com/RobTillaart/AD5144A
- https://github.com/RobTillaart/AD5245
- https://github.com/RobTillaart/AD5263
- https://github.com/RobTillaart/X9C10X
- https://github.com/RobTillaart/AD5246/ rheostat
The AD5246 has one fixed address 0x2E.
The maximum I2C speed is 400 KHz.
Sometimes you need to control more devices than possible with the default address range the device provides. This is possible with an I2C multiplexer e.g. TCA9548 which creates up to eight channels (think of it as I2C subnets) which can use the complete address range of the device.
Drawback of using a multiplexer is that it takes more administration in your code e.g. which device is on which channel. This will slow down the access, which must be taken into account when deciding which devices are on which channel. Also note that switching between channels will slow down other devices too if they are behind the multiplexer.
#include AD5246.h"The library has a number of functions which are all quite straightforward. One can get / set the value of the rheostat.
- AD5246(TwoWire *wire = &Wire) constructor
- bool begin() for UNO.
- bool isConnected() See if address set in constructor is on the bus.
- uint8_t reset() sets rheostat to midpoint = 64. (startup default)
- uint8_t write(uint8_t value) set to value 0 .. 127. Values > 127 will be mapped upon 127.
- uint8_t read() read value from cache.
- uint8_t readDevice() read value from device.
Note the AD5426 does not have a shutdown() command like the AD5245.
| define | value |
|---|---|
| AD5246_OK | 0 |
| AD5246_ERROR | 100 |
The examples show the basic working of the functions.
- keep in sync with AD5245 library
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