Module identity and antenna interface
The ESP32-C3-MINI-1U-N4 is a compact 53-SMD module built around the ESP32-C3FN4 chip, combining a RISC-V single-core MCU with 2.4 GHz Wi-Fi (802.11b/g/n) and Bluetooth v5.0 on a single board. The 'U' suffix in the order code signals that the module ships without an onboard antenna — the RF output is routed to an I-PEX connector, so the BOM must include an external antenna and a 50-ohm trace from the connector to the antenna pad. The module delivers a transmit power of 20.5 dBm and a receive sensitivity of -104 dBm, which together give the link budget for reliable connections through walls or across a typical smart-home floor plan. The 150 Mbps PHY data rate is the ceiling for 802.11n single-stream operation; actual throughput depends on the AP and environment.
Memory, supply, and temperature grade
On-chip memory includes 4 MB flash, 384 kB ROM, and 408 kB SRAM — the 4 MB flash is enough for OTA-capable firmware with a retained application image, while the 408 kB SRAM leaves headroom for the Wi-Fi stack and a lightweight RTOS heap. Supply voltage is 3 V to 3.6 V, typical for a 3.3 V rail with a 100 mV margin to the dropout. The serial interface set includes ADC, GPIO, I²C, I²S, JTAG, PWM, SPI, UART, and USB — enough to connect most common sensors, displays, and actuators without an external bridge chip.