Bk-m33-bt-v2.pcb _top_

If asynchronous serial yields no output, try toggling reset or entering DFU/bootloader mode (hold boot pins during reset).
Add temporary serial headers by soldering enamel-coated wire to exposed vias if pads are absent.
Replace suspect electrolytic capacitors and check regulators if voltage rails are unstable.
To improve Bluetooth range: check antenna clearance from ground plane, orient antenna edge away from large copper pours, and ensure matching components are present.
To conserve battery: measure sleep current; enable deep-sleep modes in firmware and disable unused peripherals.

Schematic Capture: The initial stage of designing a circuit, where components and their connections are defined.
Component Placement: The positioning of components on the board.
Routing: The layout of the copper tracks that connect components according to the schematic.
Layer Stackup: Information about the layers of the PCB, such as signal layers, power planes, and ground planes.
Design Rules: Specifications for minimum track width, spacing, hole sizes, and other manufacturing constraints.

If module uses BLE stack (SoftDevice, NimBLE, Bluedroid), load a sample BLE peripheral (e.g., Heart Rate or custom GATT service).
Test advertising with a phone Bluetooth scanner (nRF Connect Mobile or generic BLE scanner).
Confirm connections, read/write GATT characteristics, and test notifications.

Features dual-channel (stereo) output terminals for connecting a left and right speaker. Connectivity: