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CF Bolt schematic @Tobias

Posted: Sat Dec 05, 2020 10:54 pm
by leonana69
Hi, I'm curious about the schematic design of cf bolt. It seems the STM_SWIO and STM_SWCLK are not connected with the NRF, then how the NRF flash the firmware for STM32?

Re: CF Bolt schematic @Tobias

Posted: Mon Dec 07, 2020 10:23 am
by arnaud
When creating Crazyflie 2.0 we added as much functionality in the hardware as possible and this SWD connection from the nRF and the STM was intended to be able to debug the STM over the air. We never worked on that and so never used this functionality. When creating the bolt, it was inconvenient to keep the connection so we removed it.

When flashing the Crazyflie (or bolt) with the radio bootloader, there is a botloader firmware running both in the nRF and the STM and both communicates using the UART.