C# talking to an Arduino UNO using the SPI protocol

In this video I describe some of my experiments to build Nusbio+, a new version of Nusbio that will have 8 gpios, 1 spi bus, 1 I2C bus, 8 analog to digital converter and PWM. All hardware features programmable in any .NET language.

I demonstrate a first solution using the I2C mcp23008 gpio expander and the SPI MCP3008 analog to digital converter
connected to Nusbio and with that I get 10 gpios, 1 I2C bus, 1 SPI bus and 8 ADC. But no PWM.

I demonstrate a second solution using an Arduino Mini (ATMega328p 5V 16 Mhz).
To test this solution I wired a prototype where I connected an Arduino UNO to Nusbio using
SPI.

I demonstrate a C# application calling 2 api t0() and t1() in from a C firmware
running in the Arduino.