Parts for an esp8266 network clock

Everything an esp8266 network clock needs, what each part is for, and what usually goes wrong when it is substituted.

ESP8266 board (Wemos D1 mini or NodeMCU)

Any board with the ESP8266EX and a USB-serial bridge. Roughly £4–8.

0.96" I²C OLED display, SSD1306

I²C needs four wires. SPI variants exist and need six. Roughly £4.

USB power supply, 5 V 1 A

A commercial supply. This is the reason the build never touches mains. Roughly £5.

Jumper wires × 4

Female-to-female if both boards have headers. Roughly £2.

Why there are no part numbers here

A part number is verified against a supplier or it is not printed. A plausible wrong SKU reads exactly like a correct one and costs whoever trusts it real money, so parts are described in the words a supplier search will actually match.

• ESP8266 board (Wemos D1 mini or NodeMCU) — £4–8
• 0.96" I²C OLED display, SSD1306 — £4
• USB power supply, 5 V 1 A — £5
• Jumper wires — £2

Questions

What do I need to build an esp8266 network clock?

ESP8266 board (Wemos D1 mini or NodeMCU), 0.96" I²C OLED display, SSD1306, USB power supply, 5 V 1 A, Jumper wires.