The idea of the board is that it comes with the uf2 programming interface (here handled by an STM32) which can be broken off when using the board (traces go across the breaking line via traces at the top and bottom). It then has the same formfactor and pinout as a Arduino nano. The KB-link (or programming link) can be used in that case to attach to the 6 pin header (needs you to solder those on).
This is a new propduct by KittenBot; https://kittenbot.readthedocs.io/zh_CN/latest/mainboards/Nanobit.html (Chinese-only) that is a DIY board that is completely compatible with the Micro:bit as it is based on the same NRF chip. See it as a micro:bit without the LED matrix and no edge connector (but instead uses a DIL layout mimicking the nano)
The daughterboard is what replaces the NXP USB interface chip that is used to provide UF2/CMSIS-DAP. So when you break the daughterboard off, you have a small ‘nano’-sized board that runs standalone. To reprogram you can use the exposed header and reprogram it.
I am not sure if KittenBot wants to sell this outside of China, but it would seem likely. Although so far they haven’t responded to any enquiries.
@jamesadevine i also got interested in the daughterboard from the idea to perhaps use this to reprogram some of the nRF51822 chip on module I have… just need to decipher the pinout with following the traces. As mentioned, so far did not have a lot of feedback on questions I had.
I have succesfully used it to program a PTR5518 System-on-Module
I used the KB-link (KittenBot Nano:bit’s programming daughterboard) to program a System-on-Module PTR5518 to blink Micro:bit’s P8 using pins.digitalWritePin(DigitalPin.P8, 1). This pin translates to P0.18 on the NRF51822. It then sends the number out over radio using radio.sendNumber(c) to a regular Micro:bit which uses radio.onReceivedNumber to display this with basic.showNumber(receivedNumber).