# ATTiny167 USB Programming

On Aliexpress I am finding many cheap development boards with ATtiny167 and a USB connector.

From what I can gather these boards permit USB programming through USB emulation. Can anybody point me to more information on how this works?

I imagine, there needs to be a bootloader that does the USB emulation part? Is the code for it available anywhere?

I have been searching but could not find any useful information. I think I must be using the wrong keywords...

EDIT 1: justme asked for links to an example of the boards I am referring to.

One example would be this Aliexpress offer:

• We have no idea what dev boards are you talking about and how they work unless you provide a link to a specific example. – Justme May 11 at 8:45
• @Justme I added a link to an example offer on aliexpress. I thought this would be a well-known use case for the ATtiny167. I did not realise this functionality was manufacturer specific. – ARF May 11 at 9:52
• obdev.at/products/vusb/prjprog.html You have to put a V-USB bootloader on the board via ISP first (which the retailer maybe did) on from that on, you can re-flash it via that bootloader and USB. – Janka May 11 at 9:53

• The whole Microchip group survives largely on legacy products and designer inertia for a large swath of the product lineup, as chip prices haven't been competitive with numerous other chipmakers for a while. The new $1.50 blue pills often contain a knockoff chip, CS32F103C8T6, not a genuine STM, but it seems to work fine. Some chips seem to lack Boot0 serial bootloader but work with ST-Link. Then again, genuine IC is dirt cheap too (<$1 at volume, \$1.70 single), thus its high proliferation in modern Chinese products, which in turn caused clone ICs to appear. – Siana May 12 at 9:10