So what is this? It's a standalone DCF77 transmitter designed to be used with any wrist watch that is capable of receiving the signal. (Casio Wave Ceptor series etc.)
- Connects to your local WiFi network.
- Syncs the exact time via NTP and converts it to DCF77 signal.
- Shows the realtime data on the OLED display live.
- Uses screensavers to protect the screen from burn-in. (changes every minute)
- 3D printable stand.
The original Eagle design files are included as well as exported GERBER files for direct PCB production.
BOM:
- 1 x ESP32-WROOM-32 barebone
- 1 x 7 Pin SPI 0.96" Dual Color Yellow Blue OLED Display Module SSD1306 (https://hacktronics.co.in/lcd-displays/7-pin-spi-iic-096-dual-color-yellow-blue-oled-display-module-ssd1306)
- 1 x Mini USB female vertical TH (https://store.comet.bg/download-file.php?id=18384)
- 1 x MCP1826S-3302E/DB voltage regulator (https://store.comet.bg/download-file.php?id=4147)
- 3 x TANT B SMD 22uF 16V caps
- 2 x C1206 100nF 50V caps
- 2 x R1206 10K resistors
- 2 x R1206 4.7K resistors
- 1 x R1206 560R resistor
To upload the sketch you will need USB to serial UART converter capable of supplying 3.3V VCC.
Pinout for the header:
Remember that in order to boot the EPS32 in programming mode you will need to connect GPIO0 pin to GND (Low).
- Open the sketch in Arduino IDE and edit your wifi SSID and password.
- Use board "WEMOS LOLIN32" at 80Mhz flash frequency. (Tools -> Board)
- Compile and upload.
The original design file from Fusion360 is available as well as ready to print STLs.
