This project is based on ready-built cat night lights available on Amazon / eBay / AliExpress (and probably more). See also marble's BlinkenCat project on hackaday.io.
Blinkencats are sold in a variety of soft- and hardware configurations: Some use AA/AAA batteries, others have LiIon built-in; some come with an IR remote; some have proper RGB fading, others use hard transitions between RGB colors.
This page covers the variants with built-in LiIon battery. I have not yet worked with an AA/AAA based blinkencat.
- Unmarked "1200 mAh" 18650 LiIon battery with connectors soldered on, likely without protective circuitry
- TP4056 charge controller. It's specified for a fixed charge termination at 4.2V ± 1%
- 4x warm-white LED + 4x RGB LED
- Unmarked microcontroller
Battery and microUSB/button/LED PCB are housed beneath the main PCB. There is ample room for additions, e.g. a custom charge controller and/or a custom microcontroller. However, most 18650 battery holders are slightly too large for the cavern, so increasing the battery capacity is only trivial if you have a 18650 battery with connectors soldered on.
Microcontroller pinout (courtesy of marble, pin 1 is top left when rotating the board so that the microcontroller is at the bottom):
- 1: NC
- 2: Charge Status input
- 3: Piezo input
- 4: VCC
- 5: Warm White LED output
- 6: Button input
- 7: NC
- 8: Green LED output
- 9: Red LED output
- 10: Blue LED output
- 11: GND
- 12: Charge Status LED output
- 13: NC
- 14: NC
input board pinout (pin 1 is left when rotating the case so that the board is above the battery):
- 1: button contact A
- 2: button contact B, microUSB GND
- 3: LED VCC, microUSB VCC
- 4: LED GND. Note that there is no resistor on the input board
Blinkencat 1 (ATTiny2313 + stock board)
Bought in Oct 2017, PCB mark "ZL01R3". The original firmware had two modes: steady warm-white and color change (without fading and not following the RGB spectrum).
Following marble's BlinkenCat howto, I replaced its microcontroller with an ATTiny2313A and implemented various steady-color and RGB color fade modes. Idle current consumption is in the 10 µA range.
Blinkencat 2 (29C3 MiniMoodlight SMD)
Bought in Jan 2018, PCB mark "ZL01R3". The original firmware had two modes: steady warm-white and color change (without fading and not following the RGB spectrum).
I threw out the entire hardware and replaced it with a 29C3 MiniMoodlight SMD using an external USB connector.
Blinkencat 3 (ATMega328 + WS2812)
Bought in Jul 2019, PCB mark "ZL01R4". The device came with an IR remote and supported several steady-color and color-fade modes as well as a standby timer.
I removed the top PCB and replaced it with an Arduino Nano, TP4056 LiIon controller, and a WS2812 LED circle.
The Arduino Nano board consumes ~17mA even when powered down, probably due to its USB-TTL converter. There are hacks to fix this, but I did not perform them yet.
Battery runtime ranges from 1 to 6 hours depending on RGB mode.
Blinkencat 4 and 5 (stock)
Bought in Sep 2019, PCB marks "XSG139B3A 2018.8.22V2.1". The blinkencats have a redesigned PCB with significantly brighter warm-white LEDs and a diffusor. I have not modified them yet.