You are right though I do think HID is limited to 64 Kbytes/S.
But an SAMD21 or 32U4 could allow me to build a cheaper product.
I have to think about it now.
What I am currently achieving is
- 100Kbytes/S in I2C with a 10Mhz I2C EEPROM and
- 2.4 Mbytes/S in SPI with a NOR FLASH at 103Mhz
using the FTDI FT4222 and the FT232H should the same or better.
You are right there is .NET support, I used it the SPI library.
I think there one library for I2C and one for SPI.
I settled on the FTDI ft4222 which is somehow easier to program
and can only do SPI and I2C (no IO, no UART). The FT232H could be faster
in SPI.
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.
I designed Nusbio 1 to be cheap and a first USB device for .NET developers with little knowledge in electricity to start playing with IO, I2C, SPI, ADC directly from Windows and .NET languages.
It has some limitations in terms of IO default state, IO polling or speed of transfer (I2C:15Kbyte/S, SPI:15KBytes/S To 28KBytes/S). Samples in C#, VB.NET or Powershell codes are available on github.
Regarding the IO polling issue, I do not think this can be address with a Windows PC or Linux on the Raspberry PI. I tested the USB interrupt for the FTDI FT4222 and this is not very impressive.
Nusbio v2 coming sometime this year will address some of these issues, IO default state as input, increase in speed transfer (I2C:Up to 128Kbyte/S, SPI:Up to 2.4 Mbyte/S), 10 bit ADC. But unfortunately will be more expensive.
Therefore not a device for beginner or small project.
I did find some device that can do DAC/ADC or IO for $99.
I did not find one that can also do SPI and I2C.
one the web site, could give a link to a device like Nusbio
from the web site http://www.mccdaq.com/
For the ADC it would be necessary to add 8 new LEDs connected to 8 op-amp, connected to each ADC. So not out of the box.