Digital Potentiometer SPI AD5290 and Nusbio

Overview

The Digital Potentiometer AD5290 is not a regular one.

1. It provides 2 supply modes
1. Single supply, Positive voltage
2. Dual supply, Positive voltage and negative voltage
   You need to provide the positive and negative voltage (pin 1 and 2)
2. In mode 1, the current can be between 20 and 30 Volts.
   In mode 2, the current +-10 to +- 15 volts
3. It is only available in MSOP-10

Datasheet

 

SPI

The AD5290  is an SPI chip which does not use MISO (The chip does not send information back).
Be care full, the SDO pin is used for daisy-chaining

The recommended wiring with Nusbio is a follow

GPIO 0 - CLOCK
GPIO 1 - MOSI
GPIO 2 - CS

VB.net Code

Wiring

5 Volts from the USB

In this wiring, we use the Single supply, positive 5 volts mode from Nusbio and therefore from the USB.

9 Volts from a battery

In this wiring, we use the Single supply, positive 9 volts mode from a battery.
Nusbio GPIO 0,1,2 should never be in contact with the 9 Volts from the battery.