DIGI POT 7 Click is a compact add-on board used as a digitally controlled potentiometer. This board features the AD5175, a single-channel 1024-position digital rheostat with less than ±1% end-to-end resistor tolerance error and 50-time programmable wiper memory from Analog Devices. This I2C configurable IC is designed to operate as a variable resistor for analog signals, within the voltage range of single-supply operation at 2.7 V to 5.5 V. Unlimited adjustments are allowed before programming the resistance value into the programmable memory. This Click board™ can be used as a mechanical rheostat replacements, in voltage to current conversions, for gain and offset adjustment, and many more applications.

DIGI POT 7 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

DIGI POT 7 Click is based on the AD5175, a single-channel 1024-position digital rheostat, with less than ±1% end-to-end resistor tolerance error and a 50-time programmable (50-TP) wiper memory from Analog Devices. It possesses one register named RDAC that determines the resistor Wiper position and acts as a scratchpad register allowing unlimited resistance settings. The RDAC register can be programmed with any position-set using the serial interface. When a desirable Wiper position is found, this value can be stored in a 50-TP memory register. Besides, the Wiper position is always restored to that position for subsequent Power-Up.

The storing of 50-TP data takes approximately 350 ms, and during this time, the AD5175 is locked and doesn't acknowledge any new command preventing any changes from taking place. The nominal resistance between terminal W and terminal A is 10kΩ with 1024-tap points accessed by the Wiper terminal, while in the Zero-Scale condition, a total Wiper resistance of 120Ω is present. The 10-bit data inside the RDAC register is decoded to select one of the 1024 possible Wiper settings.

The AD5175 also provides the possibility of the Shutdown feature by executing the software shutdown command. This feature places the RDAC register in a Zero-Power-Consumption state where terminal A is disconnected from the Wiper terminal. The AD5175 can be taken out of Shutdown Mode by executing Software Shutdown Command or performing the Hardware Reset feature.

DIGI POT 7 Click communicates with MCU using the standard I2C 2-Wire interface, with a clock frequency up to 100kHz in the Standard and 400kHz in the Fast Mode. Besides, also allows the choice of the least significant bit (LSB) of its I2C peripheral address by positioning the SMD jumper labeled as ADDR SEL to an appropriate position marked as 0 and 1. This Click board™ can be reset via software by calling the Reset command that loads the RDAC register with the contents of the most recently programmed 50-TP memory location. This register loads with mid-scale if no 50-TP memory location has been previously programmed. It also can be reset through the Hardware Reset pin, labeled as RST on the mikroBUS™ socket, by putting this pin in a logic low state.

This Click board™ is designed to operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows for both 3.3V and 5V capable MCUs to use the I2C communication lines properly. However, the Click board™ comes equipped with a library that contains functions and an example code that can be used, as a reference, for further development.

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V or 5V
• Wiper Resistance: Typ. 35Ω, Max. 70Ω
• Resolution: 10 bits
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +125°C

• Schematic
• mikroSDK
• GitHub