# DIP Switch

If you are planning to use the flight controller without a CM4 attached, you may notice there is no power to the STM32. Normally the CM4 will active the 3.3v LDO regulator once booted, however if not fitted the switch labelled "ON if no CM4 fitted" should be activated. Please Ensure before fitting a CM4 this switch is off.

The switch labelled "ON to activate DFU/EMMC" when activated will put the STM32 into DFU mode and CM4 into EMMC flash mode. The flight controller must be power cycled to take affect. 

<figure><img src="/files/jQKUrnfpiLAHAbpy3Nt5" alt=""><figcaption></figcaption></figure>


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