NTP to GPRMC in esphome to sync a nixie clock

nixie_ntp.yaml

---
# Wemos D1 R2 (esp8266) in office for providing fake GPS time signal from NTP

esphome:
  name: nixie-ntp
  comment: NTP to GPRMC time sync for nixie clock
  includes: std_includes.h

esp8266:
  board: d1_mini

wifi:
  min_auth_mode: WPA2
  fast_connect: true
  power_save_mode: none
  domain: .iot.elwell.au
  networks:
    - ssid: Telemetry_2G
      password: !secret telemetry_pw
      hidden: true

network:
  enable_ipv6: true

logger:
  level: DEBUG

api:
  encryption:
    key: !secret api_pw

ota:
  platform: esphome
  password: !secret ota_pw

text_sensor:
  - platform: template
    # name: NMEA
    id: nmea
    update_interval: 6s
    lambda: |-
      std::string UTC_T = id(my_time).utcnow().strftime("%H%M%S");
      std::string UTC_D = id(my_time).utcnow().strftime("%d%m%y");
      std::string out1 = "GPRMC," + UTC_T + ",A,4307.316,S,14713.705,E,0.0,000," + UTC_D + ",,,A,M";
      char checksum = 0;
      for (char c : out1) {
          checksum ^= c;
      }
      std::stringstream cs;
      cs << std::hex << std::uppercase<< (int)(unsigned char)checksum ;
      std::string out2 = "$" + out1 + "*" + cs.str();
      return {out2};
    on_value:
      - uart.write:
          id: nixie_sync
          data: !lambda |-
            std::string str = id(nmea).state + "\r\n";
            std::size_t pos;
            return std::vector<uint8_t>(str.begin(), str.end());

time:
  - platform: sntp
    id: my_time
    timezone: Australia/Hobart
    servers:
      - time.vk7hpc.net

uart:
  tx_pin:
    number: GPIO2
    inverted: true
  baud_rate: 4800
  id: nixie_sync