Jumper Settings

The following list shows the jumper configuration of the hardware platfom. Directions such as ‘left’, ‘right’, ‘top’, and ‘bottom’ are always defined from a top view of the PCB, with the silkscreen text readable. Pin numbering follows standard numbering conventions (e.g., top-to-bottom or left-to-right, depending on the connector type or orientation of the component).

Jumper Settings

Id	Name	Default	Description
-	- (POWER_DEBUG)	Closed, 2 jumpers from top to bottom.	[Debug] Enables main power for the TBB board. See white box “Debug” printed next to the USB port for further configurations.
-	CN_SENSOR	Connected	Connector for the sensor. See P_DOWN if and pull down resistor is required.
-	P_DOWN	Open	Enables an additional 1k Ohm pull down resistor for the sensor if bridged.
-	PI_BOOT_MODE	Open	The CM4 can be forced into different boot modes when bridged. nRPIBOOT: Bridge pin 1 and 2 to force booting from an RPI server. EEPROM_nWP: Bridge pin 3 and 4 to prevent writing to the on-board EEPROM which stores the bootcode.
-	PWR_LED	Connected	Connector for the power led (PWR_LED)
-	USR_LED	Connected (DO OT SHORT!)	Connector for the user LED (USR_LED).
CN3	BT_LED	Connected	Connector for the bluetooth status LED (BT_LED)
CN6	-	Open	Connector to flash the STM. Same as U12.
J1	VREF	Closed	Input for the reference voltage. If bridged, the internal 3v3 is used. Can not left open. When using an alternative reference voltage, connect it to pin 1.
J2	STM_RESET	Open	[Debug] Short to manually reset the STM.
J4	-	Open	[Debug] Add capacitors to stabilize the input voltage. Pin 1 and 2 for 100 nF or Pin 2 and 3 for 200 nF.
J5	“PI_STM_RST”	Open	Bridge to allow the PI to reset the STM via a pin. The pin must be pulled to GND by the PI.
J7	AGND	Closed	Connection for analog ground. If bridged, analog ground is connected to ground of the TBB board. Cant be left open. If an alterantive ground should be used, connect it to pin 1.
J8	USR_BTN	Connected (DO NOT SHORT!)	Connector for the user button (USR_BTN).
J11	VCAP2	Open	Bridge to short the VCAP2 capacitor when the internal voltage regulator of the STM is bypassed (e.g., when an external core voltage is supplied). Closed: VCAP2 shorted to GND. Open: VCAP2 pin connected to capacitor (internal regulator enabled, normal operation).
J12	BOOT0	Bridged (pin 2 and 3)	Defines the state of the STM’s BOOT0 pin. - 3v3 (pin 1 and 2): Boot from flash memory - GND (pin 2 and 3): Boot from system memory (default)
J13	CM4_USB	Closed	USB OTG Pin. When bridged the CM4 becomes a USB host (master) and slave otherwise.
J14	IO_PORTS	Open	Interface to access internal IOs of the STM and IO-Expander.
J16	VCAP1	Open	Bridge to short the VCAP1 capacitor when the internal voltage regulator of the STM is bypassed (e.g., when an external core voltage is supplied). Closed: VCAP1 shorted to GND. Open: VCAP1 pin connected to capacitor (internal regulator enabled, normal operation).
J17	-	Open	[Debug] TTL interface for CM4
J18	PI_RESET	Open	[Input] Drive low (bridge) to power off CM4.
J20	-	Open	If supported wireless and bluetooth interfaces of the CM4 can be disabled. To disable the wireless interface, connect pin 2 and pin 3 (WL_nDis). To disable Bluetooth, connect pin 1 (BT_nDis) and pin 2.
J21	nEXTRST	Open	[Output] Driven low during reset; Driven high (CM4_3.3V) once CM4 CPU has started to boot
J23	-	Pin 2 (3V EN) and pin 3 (PI) bridged	Select the source for enabling the 3v3 rail on the TBB board. Using default, the pi enables the 3v3 rails. When bridging pin 1 (DEFAULT) and pin 2 (3V EN), the 3v3 rail is active whenever a USB cable is plugged.
SW1	CAN-120R	On (right)	Enables and disables the 120R resistor for CAN.
U12	-	Open	Connector to flash the STM. Same as CN6.