MDBT42T Series, Bluetooth 5.4, LGA module; nRF52805 based
- Technology
- Bluetooth modules
- Partner
- Raytac
This module series is pre-loaded with Raytac’s AT command firmware and operates in the Peripheral / Slave role. It is based on the Nordic nRF52805 SoC and is a Nordic-recommended third-party module. The module is Bluetooth certified for BT 5.4, 5.2, 5.1, and 5.0, and holds global certifications including FCC, IC, CE, TELEC (MIC), KC, SRRC, and NCC.
It features a 32-bit ARM® Cortex™-M4F CPU with 192 kB Flash memory and 24 kB RAM, and is RoHS & REACH compliant. The compact 7.2 × 11.2 × 2.05 mm form factor includes 10 GPIOs and an integrated chip antenna. The module supports a UART interface, offers an MTU of up to 247 bytes, and is designed to work with MDBT42Q-ATM / MDBT42Q-PATM modules operating in the Central / Master role.
Range features
A high level overview of what this range offers
- Device name configuration
- 1 Mbps / 2 Mbps on-air data rate
- 5-level TX power control
- Adjustable advertising and connection intervals
- Advertising enable/disable with status LED patterns
- 7 UART baud rates, with hardware interface & flow control enable/disable
- 8 programmable GPIOs with power-down & GPIO wake-up
- DC-DC or LDO power mode selection
- Internal or external 32.768 kHz oscillator
- Hardware & software reset and factory default recovery
- Serial number & MAC address set/retrieve
- Battery ADC monitoring
- Max MTU 247 bytes, payload up to 244 bytes
What’s in this range?
All the variants in the range and a comparison of what they offer
Model number | MDBT42T-AT |
Wireless technology | Bluetooth Low Energy |
Bluetooth specification | Bluetooth 5.4, 5.2, 5.1, 5 |
Operating role | Peripheral / slave |
SoC / CPU | nRF52805-based, 32-bit Cortex-M4F |
Memory | 192 kB flash, 24 kB RAM |
Antenna | Integrated chip antenna |
Host interface | UART, 7 selectable baud rates, optional flow control |
On-air data rates | 1 Mbps, 2 Mbps |
Max MTU / payload | 247 bytes MTU, up to 244 bytes payload |
GPIO | 10 GPIO pins total, 8 configurable via AT commands |
Power features | Power-down mode, GPIO wake-up |
Supply modes | DC-to-DC and LDO supported |
Dimensions (L × W × H) | 7.2 × 11.2 × 2.05 mm |
Compliance / approvals | Bluetooth 5.x, FCC, IC, CE, Telec (MIC), KC, SRRC, NCC, RoHS, REACH |
FAQs
for MDBT42T Series, Bluetooth 5.4, LGA module; nRF52805 based
The MDBT42T-AT is designed as a Bluetooth Low Energy peripheral module with pre-loaded AT command firmware. It is intended for devices that need BLE connectivity controlled over UART, such as sensors, small controllers and simple wireless nodes, without requiring developers to implement the Bluetooth stack themselves.
The module is certified for Bluetooth 5.4, 5.2, 5.1 and 5, providing compatibility with modern Bluetooth LE hosts and enabling features such as higher throughput and improved robustness compared with earlier revisions.
The module communicates with a host via a UART interface. The host sends and receives AT commands and status messages over this serial link, with seven selectable baud rates and optional hardware flow control to match a wide range of host platforms.
Internally, the MDBT42T-AT integrates an nRF52805-based SoC with a 32-bit Cortex-M4F CPU, 192 kB of flash memory and 24 kB of RAM. These resources support the AT firmware as well as user-specific behaviour such as GPIO control and configuration storage.
Yes. The module supports DC-to-DC and LDO power modes, a power-down mode for very low current consumption and wake-up via GPIO. Combined with Bluetooth LE operation and adjustable advertising and connection intervals, this makes it suitable for battery-powered designs.
The MDBT42T-AT provides 10 GPIO pins, with 8 of them configurable via AT commands. These pins can be used for typical functions such as driving LEDs, reading buttons, controlling external circuitry or sensing logic-level signals.
The module supports an MTU size of up to 247 bytes, allowing a data payload of up to 244 bytes per packet. This helps improve effective throughput and reduce protocol overhead for applications needing to transfer larger chunks of data.
The module is certified to the Bluetooth 5.x specification and holds a range of regulatory approvals including FCC, IC, CE, Telec (MIC), KC, SRRC and NCC, as well as RoHS and REACH environmental compliance. These approvals help streamline product certification and market access.
Yes. Within the same module family there are central-role modules such as MDBT42Q-ATM and MDBT42Q-PATM. The MDBT42T-AT is intended for peripheral role, and can be used in combination with these central modules to create complete Bluetooth LE systems.
Dedicated documents are available, including a detailed specification, a footprint and design guide with layout and reflow information, and a RoHS & REACH report. These resources support PCB layout, mechanical integration, soldering process setup and compliance documentation.
