Fish Feeder Project

cults3d

This project is a remix of "Automatic Fish Feeder with micro servo control V2" by Paulo Cunha. I have made some changes to the design, redesigned the hopper, added a base part and control box. Initially, I used the original design with a mixer inside the hopper powered by a spur gear. However, flake food was sometimes jammed in the hopper and the mixer did not help prevent this situation. Therefore, I removed the horizontal mixed and added a much bigger vertical mixer powered by an additional servo motor. After two months of operation, it seems to be quite reliable. Video: https://youtu.be/azTHyCNVLFo The electronics are based on the ATTiny841 chip programmed in Arduino IDE. The main goal was to keep power consumption low. The cpu is mostly in sleep mode, and there is no display. Operation is triggered by a real-time clock module DS3231. Powered by a single 18650 Li-ion Rechargeable Battery. I have selected the ATTiny841 because it has an integrated hardware serial interface. It is used for setting time, alarms, etc. I did not use Arduino Mini etc. because I had to create a pcb board for other components anyway so I included cpu there. By other components I mean n-channel mosfet switches mainly. Two 9G servo motors are used – modified to work as a DC motor (removed electronics and connected directly to motor, cracked potentiometer to allow free rotation) Features: • precise real-time clock • two independent programmable alarms (feeds) in a day • programmable via serial link • adjustable time duration for auger and mixer servo (separately) • button for instant feed (out of alarm time) • buttons for adjusting feed servo run duration • indication of low battery voltage Electronics The electronics are quite simple – ATTiny 841 controls servo motors via two n-channel mosfet switches. RTC board and Li-ion charger board are available at ebay.com: RTC DS3231: http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XIIC+Precision+RTC+Real+Time+Clock+Memory+Module++DS3231+AT24C32.TRS0&_nkw=IIC+Precision+RTC+Real+Time+Clock+Memory+Module++DS3231+AT24C32&_sacat=0 CHARGER: http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XMini+USB+Lithium+Battery+Charging+Board.TRS0&_nkw=Mini+USB+Lithium+Battery+Charging+Board&_sacat=0 Detailed description in attached pdf file. Source Arduino, Eagle, Inventor files are attached too.