An alarm clock with light instead of sound, simulating a sunrise, with NTP time synchronization, and with programmable alarm times for each day of the week.
This code works on the esp8266 wifi module with the nodemcu firmware. It was successfully tested on an ESP-01 and an ESP-12E.
Click on this image to the web interface in action:
For no good reason, the interface is partly in Japanese (月曜日 is "Monday", etc.).
The "Toggle" button toggles the time zone between CET and CEST.
Setting different time zones amounts to changing the offsets in
src/time.lua.
Eventually daylight saving time (DST) should toggle automatically based on the time zone, but this would require keeping track of the date, which is not implemented yet. The wakelight remembers the status of daylight saving time after power loss, as well as the alarm times.
Any esp8266 module will do, even the cheap ESP-01 ($1-$2 on aliexpress). First you need to flash it with a recent nodemcu firmware. Don't use prebuilt firmwares, those are far too old and won't work. Either compile your own or use http://nodemcu-build.com/ to get a recent firmware. You need to enable at least the following modules: file, gpio, net, node, rtcmem, rtctime, sntp, tmr, uart, wifi, ws2812.
The LEDs must be WS2812B modules. You can change the number of LEDs
in globals.lua. The default for NUM_LEDS is 144, which is the
number of LEDs on a common high density 1m strip. For increased
brightness, you can connect multiple strips in parallel without
changing NUM_LEDS, or concatenate them and increase NUM_LEDS (I
would recommend the former because the timing of these LEDs strains
the ESP chip). I would say that two 1m strips (144 LED/m), a total of
288 LEDs, are the minimum for adequate brightness. Unfortunately the
WS2812B LEDs are not very efficient compared to modern LED bulbs.
Please be aware that driving the LEDs requires quite a lot of power (>25W for 144 LEDs). A 5V cellphone charger or a computer USB port will not work.
The LEDs must be connected to pin 4 of the ESP chip. The ws2812 module in nodemcu only works on the serial transmitter pin, which happens to be pin 4.
You may also need a level shifter between the LEDs and the ESP because the ESP is 3.3V but the WS2812B LEDs are 5V. In my case it also worked without a level shifter, but adding one reduced glitches on the LED strips.
The wakelight accepts over-the-air updates of lua files from the
script ota_upload.sh. There is currently no authentication.
The schematic uses the ESP components from https://github.com/jdunmire/kicad-ESP8266 .
Because I could not readily find a level shifter component in kicad, I omitted that part in the schematic. The actual hardware has a TXS0108E between pin 4 of the ESP chip and the WS2812B LED input.
There is also a very simple mood light feature that you can
enable/disable manually from the web interface. This is mostly an
experiment and serves no purpose. Currently implemented is red, green
and white light. Edit the file src/mood.lua if you would like to
implement more complex lighting scenarios.