Of course you’d expect hardware-based USB to outperform software emulated USB. Teensy 2.0, and Arduino Leonado and every other board based on ATMEGA32U4, have USB implemented in hardware. Of course, comparison to Teensy isn’t really fair on a technical level (I’m the creator of Teensy, for full disclosure). I haven’t personally investigated this, but I do try to pay attention to USB stuff, especially when people discover the limits and specific issues with each operating system. I’ve read that many operating systems allowed this anyway, but I also saw somewhere than some newer versions of Windows started to enforce this rule and refused to enumerate such devices. Using bulk and isync are forbidden by the USB spec. The other issue with bulk endpoints is the USB spec only allows control and interrupt types on low speed devices. I’m not doubting someone’s found a clever solution… I’m really interested to see how they’ve solved this. Previously when people have tried bulk endpoints, the rapid pace of IN tokens has consumed most of the CPU time. For IN direction (device to PC) bulk endpoint, the USB host controller chip polls the USB device pretty rapidly with IN tokens. Normally bigbang USB implements only control and interrupt mode endpoints. The bulk endpoints used by CDC are a special challenge. I know the technique has been around for many years, but still, it’s pretty amazing. I’m always amazed by bitbang USB implementations like V-USB. Posted in ATtiny Hacks, Crowd Funding Tagged ATtiny167, attiny85, Digispark Post navigation Without the shields, the Digi Pro is cheap, and only $2 more per board than the original Digispark. There are also a few more shields this time around, with WiFi and Bluetooth shields available as additional rewards. There’s real USB programming, device emulation, and serial over USB this time, and the ability to use the Arduino serial monitor, something not found in the original Digispark. This larger, 20-pin chip adds 10 more I/O pins, and a real hardware SPI interface, but the best features come with the Digispark Pro package. The new board isn’t based on the ‘tiny85, but rather the ATtiny167. The Digispark was among the first of these small boards, and now the creator is releasing a newer, bigger version dubbed the Digispark Pro. This small 8-pin microcontroller is able to run most Arduino sketches, and the small size and low price of these dev boards means they have been extremely popular. There has recently been a huge influx of extremely small dev board based on the ATtiny85.
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