Arduino based temperature sensor with Nokia 3310

Building projects with Arduino is easy especially if all building blocks are within reach of your hand. This project is simply assembly of three parts: Freeduino, Nokia3310 LCD and HSM-20G temperature and humidity sensor. Operation is straight forward. It measures ten points of temperature and humidity and then displays averaged value on LCD screen. State accuracy is about 3 degrees and 5%RH unless you calibrate sensor. Continue reading

AVR based automatic dog feeder

Tommi inspired by automatic cat feeder decided to make something similar for his dog. He came up with AVR microcontroller based cereal dispenser. Dispenser propeller is moved with help of DC motor. It is programmed to feed dog three times a day. Instead of struggling he simply purchased wall mount dispenser which is usually used in candy shops and attached a DC motor to its propeller. Ne fixed dispenser to wooden box where bag of cereals are stored. Electronics side has some guts too. AVR microcontroller drives motor through L293D motor controller chip. Timekeeping is done by using DS1307 RTC chip. As for user interface there is a Nokia 3310 LCD used where various information is displayed. Tommi seems to be excited about this project so he talks about future versions of it with more cool features. Continue reading

Nokia 3310 scope project

Nokia 3310 graphical display seems to be very popular among embedded hobbyists. Probably because of it’s availability, lots of examples over the internet and simplicity of interfacing. Wichit Sirichote has developed simple scope application by using his project 8051SBC board. Interfacing of display is very simple as it uses serial interface. The only thing you should take care when using 5V logic is to reduce LCD voltage to 3V level. This can be simply done by using two general purpose diodes connected in series. This provides approximately 1.4V drop. Source code is available for your experiments. Also you can see live action of this simple scope in this video. Of course this scope can’t assure you proper characteristics but this example gives you great info about interfacing 3310 LCD. Continue reading