You are right in some ways Nusbio and an Arduino with a UART, in term of features may not be that different. With an Arduino specially Chinese Arduino compatib

You are right in some ways Nusbio and an Arduino with a UART, in term of features may not be that different. With an Arduino specially Chinese Arduino compatible CH340 or with .NET languages you may be limited to 115200 bauds (about 11Kbyte/S) and you need to write and maintain a firmware. As a plus you get PWM and ADC. Nusbio1 can do between 15 and 28 Kbytes/S in SPI and there is no firmware. But there is no PWM. ADC or DAC are available as SPI extensions. it is not a black and white answer. But with the knowledge I acquired creating Nusbio 1 hardware and software, I am now working on Nusbio 2. Nusbio v2 coming sometime this year will address some of these issues, IO default state as input, increase in speed transfer (I2C:Up to 128 Kbyte/S, SPI:Up to 2.4 Mbyte/S), 10 bit ADC, PWM. But unfortunately will be more expensive. see https://twitter.com/MadeInTheUSB/status/848013033335029761 https://twitter.com/MadeInTheUSB/status/848013033335029761