First of all, excuse me for bad English. This is not my native language. The text is pretty big and I was too lazy to translate it myself, so I used Google Translator.
The project on the microcontroller ATTiny2313, the scheme in the picture:NorthStar NaviCube for iRobot Braava & Evolution Robotics Mint:
The cube number is set with jumpers JP0-JP1. The current version of the program can generate signals from cube #1 and cube #4. The parameters of the signals of cube #2 and cube #3 are not yet known to me.
The cube is turned on by short pressing the button. After switching on, it works for 2 hours, after which it turns off. During operation, the mode LED flashes at a frequency of 0.5 Hz. By pressing the button again, the cube can be turned off early.
For power supply is assumed lithium battery. A node on the TL431 is designed to control the battery voltage: when the supply voltage drops below 2.5V, the device will produce several series of "3 + 1" short flashes by the mode LED, and then turn off. The same effect will be when you try to turn on the device with a discharged battery. If the battery voltage control is not needed or another source is selected for power, the node on the TL431 can be removed, and the input "PB4" can be set to "0".
The battery is supposed to be used protected, therefore for charging the usual USB-charger is used.
When repeating a device, the IR-LEDs should be installed at about 120 degrees relative to each other and with an inclination of about 15-20 degrees "forward" (ie, to the center of the room).
The principle of the formation of the navigation cube of two "infrared spots" on the ceiling:
Firmware in .bin and .hex formats here - https://yadi.sk/d/_ut1UjUiLgszvw
PS: The cost of a cube at the official store at the moment is 40$!
Last edited by Serge_ISA
on January 11th, 2019, 3:25 pm, edited 3 times in total.