This device developed for monitoring car accumulator battery and notifying in case of problems with batt or generator. It has a four LEDs with the next states:
- Red (high - LED4) - power is over 14.5V means that something wromg woth generator
- Red (high - LED4) + Green (LED3) - generator works and battery in charging mode
- Green (LED3) - battery charged and power in range of 99-40%
- Green (LED3) + Yellow (LED2) - battery discharged and power in range of 40-30%
- Yellow (LED2) - battery discharged and power in range of 30-20%
- Yellow (LED2) + Red (low - LED1) - battery heavy discharged, i.e. power in range of 20-10%
- Red (low - LED1) - critical discharging, power less than 10%
Scheme:
Possible variant of PCB:
To build firmware on Linux shuld be installed next tools (example for Ubuntu):
sudo apt-get install gcc-avr avr-libc avrdude
To use AVR dragon for flashing (for now make file hardcoded only for this programmer) should be added Udev rules:
- Create new rules file in Udev folder:
sudo vim /etc/udev/rules.d/51-avr.rules
- Add these string to rule file
ATTR{idVendor}=="03eb", ATTR{idProduct}=="2107", MODE="666"
- Restart Udev daemon
sudo service udev restart
Build rules:
- just "make" or "make all" or "make firmware" - will be created firmware for ATTiny13
- "make fuses" - device will be flashed via SPI with correct fuses
- "make flash" - firmware shall be uploaded to ATTiny13
- "make clean" - all generated files will be removed