M5Stack NB-IoT 2 Unit Golbal Version (SIM7028) with Antenna

M5Stack NB-IoT2 Unit for Global Cat-NB Deployments

The M5Stack NB-IoT 2 Unit uses the SIM7028 communication module to add multi-band Cat-NB connectivity to embedded systems. It connects to a host through UART at 115200 bps and is controlled with AT commands, making it practical for remote devices that need small, periodic data transfers rather than high-bandwidth communication.

A Nano SIM slot and external SMA antenna interface are integrated into the compact Unit enclosure. Supported Cat-NB bands include B1, B2, B3, B4, B5, B8, B12, B13, B14, B17, B18, B19, B20, B25, B26, B28, B66, B70, and B85. Before ordering, confirm that the intended mobile operator supports NB-IoT service on a compatible band at the deployment location. Multi-band hardware does not guarantee local operator coverage.

Build Low-Throughput M5Stack IoT Nodes

For m5stack iot projects such as metering, asset tracking, remote monitoring, and distributed alarms, NB-IoT can provide carrier-network connectivity without relying on a local Wi-Fi access point. The specified data rates are up to 127 kbps downlink and 159 kbps uplink, fitting telemetry and control workloads where payloads are relatively small.

UART AT Commands Keep Host Integration Clear

The main controller communicates with the SIM7028 through UART and AT commands. This separates application logic from cellular modem control and gives firmware teams a clear workflow for SIM detection, network registration, signal checks, APN or operator configuration where required, socket setup, and application-protocol testing.

Protocol Options for Remote Data Paths

The module documentation lists support for protocols including TCP, UDP, HTTP, DNS, NTP, PING, LwM2M, MQTT, MQTTS, and SSL, with some additional listed functions carrying qualification notes in the official specification. Validate the exact firmware and protocol requirement before committing to a production architecture, especially where TLS behavior, certificates, or operator certification are critical.

Power and Deployment Planning

Specified current figures are approximately 3.1mA at 5V in standby and 36mA at 5V during the stated network test condition. Complete battery sizing should also include the host controller, sensors, regulator losses, network-registration time, retries, reporting interval, and local signal quality.

Technical setup details are available in the M5Stack NB-IoT2 documentation.