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. [via]
Nokia 3310 scope project - [Link]
Frequency counters are very popular and easy to build projects. This one is a AT90S8515 microcontroller and Lattice ispLSI2032 PLD based frequency counter. While microcontroller mainly takes care of communicating and data display, PLD counts incoming pulses and scales them down because of hardware 36bit counter implemented. When counter counts up – it generates an interrupt for MCU.
Frequency counter also has ability to communicate with PC via serial port. This way counter can log data to computer or be simply controlled by computer. Project files and source codes are available for download in project page. [via]
Universal frequency counter - [Link]
The Lux Meter is usually used to measure illumination. The illumination is how level of luminous flux is falling on a surface area. The luminous flux is visible component that is defined in radiant flux (light power) divided by relative sensitivity of human eyes over the visible spectrum. This means the Lux is well fit to light level from sense of human eyes.
However there is a difference between spectra response of ordinary silicon photo diode and human eyes, it cannot be used for the lux meter. Some photo diodes for illumination sensor have a color compensation filter on the window to correct its spectra response. [via]
DIY Lux Meter - [Link]
How to create a temperature controller for a CPU cooling fan (or similar cooling fan for other electronics) only a few bucks and a handful of parts. [via]
Cooling fan temp controller - [Link]
This is a very small telephone exchange attached only two ordinary Tele phones. Fully bi-directional facility with an intercom system. When a phone is in off hook condition , Exchange will detect it & send ringing pulse to other phone. When it will be picked up , the connection will be established between both phones. This will be taken place vice-versa.
Two way Simple Very Small Telephone Exchange - [Link]
CMoy is a very simple and portable headphone amplifier. The amplifier was originally posted by Chu Moy on headwize.com. Headphones amplifiers are usually used when the output of a device is to low for the kind of headphones you’re using, or to get better sound quality by keeping the device on a medium volume setting and amplifying the sound with the headphone amplifier. I’ve not build this amplifier so far, so i cant tell you from my personal experience if it sounds good or bad, but from what i read on the internet, users that build it are very happy with the results. The schematic is very simple, parts are easy accessible so it should go really smooth with the building process if you decide to do it.
CMoy Headphone Amplifier - [Link]
This project’s display is made of a number of tiles, about 2″ square with an 8 x 8 array of color LED pixels. Each tile is individually powered and animated, so your can freely pick them up and re-arrange them. To set up a display, the tiles are placed in a special tray. Animations are downloaded into the tray via Ethernet and stored locally on an EEPROM, or loaded via an SD card. The tray broadcasts the animation to each of the tiles, and then synchronizes them.
If the pieces are left in the tray, the animation can be updated continuously over the Ethernet connection. If the tiles are removed from the tray, they’ll display the animation for several hours with their own re-chargeable battery power. Once the animation is synchronized and running on the tiles, you can pick them up and place them anywhere.
Dynamic Tiled display - [Link]
This is a small little g-meter that attaches to your car windshield like gps units do. Cars normally measure speed & distance…now you can see your acceleration via the g-meter.
The Personal G-Force Meter - [Link]
Micrometals, Inc. has thoroughly reviewed this design software and the equations utilized to calculate the suggested windings and believe the information to be accurate. It is important to note that the default settings can be altered and unacceptable designs generated. Before using this product, the buyer agrees to determine suitability of the product for their intended use or application. Micrometals shall not be liable for any loss or damage, including but not limited to incidental or consequential damages as a result of the use of this software. [via]
Inductor Design Software - [Link]