Why it's interesting for IoT nodes
Small sensor gateways and display nodes often use a Raspberry Pi Zero. The BPI-M4 Zero keeps the form factor and 40-pin connector of the Pi Zero W (Banana Pi says it fits most Pi Zero W cases and accessories) and adds onboard eMMC, so the node doesn't depend on an SD card.
| BPI-M4 Zero (Banana Pi specification) | |
|---|---|
| SoC | Allwinner H618, 4x Cortex-A53 up to 1.5 GHz, Mali-G31 GPU |
| RAM | 2 or 4 GB LPDDR4 |
| Storage | 8 or 32 GB eMMC, microSD |
| Wireless | 2.4/5 GHz Wi-Fi and Bluetooth 5.0 — except the K016 module variant, which has no 5 GHz |
| USB | 1x USB 2.0 Type-C host, 1x USB 2.0 Type-C OTG (also power input) |
| Video | mini HDMI 2.0a |
| GPIO | 40-pin header (28 GPIO; UART, SPI, I2C, PWM, I2S) |
| Extra | 24-pin FPC connector with USB 2.0, IR, 100 Mbps Ethernet and more GPIO |
| Power | 5 V / 3 A via USB Type-C |
The Wi-Fi module pitfall
Banana Pi's docs state that boards with the K016 Wi-Fi module don't support 5 GHz Wi-Fi (the K019 module is Wi-Fi 5). If your deployment needs 5 GHz, for example because 2.4 GHz is crowded or reserved for Zigbee, check which module your board has before buying in quantity.
Getting wired Ethernet
There's no RJ45 jack. The 24-pin FPC connector carries a 100 Mbps Ethernet interface, so a wired connection needs an adapter board on that connector (or a USB Ethernet adapter on the host port).
Software
Armbian lists the board with Standard support, and Banana Pi's own images for it are Armbian-based. GPIO libraries: see the Banana Pi GPIO item (RPi.GPIO port limits).