The nRF21540 DK has a range of solder bridges for enabling or disabling functionality on the Development Kit (DK). Changes to these are not needed for normal use of the DK.
The following table is a complete overview of the solder bridges on the nRF21540 DK.
| Solderbridge | Default | Function |
|---|---|---|
| SB5 | Closed | Cut to disconnect LED1 |
| SB6 | Closed | Cut to disconnect LED2 |
| SB7 | Closed | Cut to disconnect LED3 |
| SB8 | Closed | Cut to disconnect LED4 |
| SB9 | Open | Short to bypass peripheral power switch |
| SB30 | Open | Short to reset the interface MCU |
| SB31 | Open | Short to bypass the USB detect switch |
| SB32 | Open | Short to permanently enable the I2C pull-up resistors |
| SB33 | Closed | Cut to permanently disable the I2C pull-up resistors |
| SB34 | Open | Short to bypass the power switch on the USB power |
| SB36 | Open | Short to bypass the power switch on the external supply power |
| SB37 | Open | Short to bypass the interface MCU power switch |
| SB38 | Closed | Cut to disable VDD power to the Arduino interface |
| SB39 | Open | Short to bypass the power switch for regulator or external supply |
| SB40 | Closed | Cut for current measurements of the VDD_nRF |
| SB41 | Closed | Cut for current measurements of the VDD_nRF_HV |
| SB42 | Closed | Cut to disconnect IF Boot/Reset button from nRF52840 reset pin when the interface MCU is disconnected |
| SB43 | Open | Short to connect IF Boot/Reset button to RESET pin on the Arduino interface |
| SB44 | Open | Short to connect the RESET pin on the Arduino interface to the nRF52840 reset pin |
| SB45 | Open | Short to connect the RESET pin on the Arduino interface to the interface nRF52840 reset pin when the interface MCU is disconnected |
| SB46 | Open | Short to connect the RESET pin on the Arduino interface to the interface MCU Boot when the interface MCU is disconnected |
| SB47 | Open | Short to enable power supply of the external device when using the debug out connector |
| SB48 | Open | Short to bypass the interface MCU USB power switch |
| SB49 | Open | Short to connect VDD_UTMI to VDD_SAM |
| SB50 | Closed | Cut to disconnect the nRF52840 CTS line from the signal switch and interface MCU |
| SB51 | Closed | Cut to disconnect the nRF52840 RTS line from the signal switch and interface MCU |
| SB52 | Closed | Cut to disconnect the nRF52840 RxD line from the signal switch and the interface MCU |
| SB53 | Closed | Cut to disconnect the nRF52840 TxD line from the signal switch and interface MCU |
| SB54 | Closed | Cut to disconnect the nRF52840 SWDIO line from the signal switch and interface MCU |
| SB55 | Closed | Cut to disconnect the nRF52840 SWDCLK line from the signal switch and interface MCU |
| SB56 | Closed | Cut to disconnect the nRF52840 RESET line from the signal switch and interface MCU |
| SB57 | Closed | Cut to disconnect the nRF52840 SWO line from the signal switch and the interface MCU |
| SB58 | Closed | Cut to disconnect voltage follower from external supply when SW10 is in ON position |
| SB59 | Open | Solder to connect debug in and trace reference voltage to VDD |
| SB60 | Closed | Cut to disconnect debug in and trace reference voltage from VDD_nRF' |
| SB65 | Closed | Cut to disable the pull-up resistor of the IMCU_BOOT line |
| SB80 | Open | Short to bypass the power switch for the VBUS of nRF52840 |
| SB81 | Open | Short to bypass the power switch for VDD_HV of nRF52840 |