Arduino library for AD5161 I2C/SPI digital potentiometer

v1.0 - First release

This potentiometer has 256 steps, VDD 2,7-5,5V, exists with R=5K, 10K, 50K, 100K

This device can be driven using either I2C or SPI buses. This library supports both busses.

AD5161's Analog Device page.

Features

• Move to a positon straight, by step or by step and time
• Move by a differential value
• Get current stepper position
• Get current operation mode (stopped, by step, by time)
• Set at mid scale
• Enabling / disabling debug to Serial output

Example

A simple voltage divider moving along the full scale of the potentiometer. The Serial output is the stepper position read from the lib and extrapolated from AnalogRead()

Testing

• Tested only against AD5161BRM5
• Tested on Arduino Mega with Arduino IDE 1.0.5
• Please comment about other devices

Documentation

ANALOGDEVICE_AD5161(void)
		Create object for device in SPI mode, all other data got from #define section of header file

ANALOGDEVICE_AD5161(boolean SpiI2c_mode, uint8_t cs_pin, uint8_t ad0_value)
		Create object for device over SPI or I2C, with a way to specify CS pin and AD0 value for I2C address.  All other data got from #define section of header file
		Set unused variables to 0

ANALOGDEVICE_AD5161(boolean SpiI2c_mode, uint8_t cs_pin, uint8_t ad0_value, uint8_t nb_step, uint16_t R_value)
		Fully speccified device. Set unused variables to 0

init()
		Used to init the object. This is mandatory. As default the debug mode is disabled

update()
		This function must be called in the loop function of your sketch to allow proper step by step working

moveTo_byStep(int8_t position, int8_t step_size)
		Move to a specified position with a step size
		A 0 step size means a straight move

moveTo_byTime(int8_t position, int8_t step_size, unsigned long min_time)
		Move to a specified position with a step size. Each step is done every min_time
		
moveBy(int decalage, uint8_t mode)
		Move from current position to position + decalage
		Step mode = 1, Time mode = 2

setMidscale()
		Set stepper in the middle of the potentiometer

getPosition()
		Read position from device in I2C mode
		Return last known positon in SPI mode

getRvalue()
		Calculated R value according to position

getOpMode()
		Return Operation mode
		0: stopped, 1:ongoing move by step, 2: ongoing move by time

enable_debug (boolean status)
		Start or stop Serial debug output
		status: true = output activated
		status: false = output stopped