NOV20
Ultra-compact LM4780 audio amplifier
Here is a very nicely built audio amplifier.
It has it's own dual power supply, very simple schematics for the amplifier part and nice looking box to fit it all inside. It is based on LM4780 IC which gives 60W per channel (and it has two channels). No PCB was designed for the amplifier part since point-to-point wiring was used.
Source: Mark Hennessy
NOV16
LIDAR gun tester with Arduino
LIDAR is a device that police uses to measure speed of vehicles. Lidar detector is a device that we use to detect those lidars and lower our speed before it is too late.
We don't know if our lidar detector works before police hits us with their lidar signal so it is a good practice to test it out once in a while. This can be done by reproducing the same IR impulse that lidar is sending and that's just an impulse of certain frequency. This lidar tester or lidar simulator can do just that and since there are many lidars with different frequencies, this device can simulate many of them including: Jenoptik Laveg, Jenoptik LaserPatrol, Kustom Prolaser 1, Kustom Prolaser 2, Kustom Prolaser 3, Kustom ProLite, Laser Atlanta, Stalker LZ-1, Ultralyte 100/200 LR Revision 1, Ultralyte 100/200 LR Revision 2 and Ultralyte Non-LR.
Source: BlackLight99
NOV13
Coating electronics in clear polyester resin
No project is complete until it is placed in a project box (this automatically means that most of my projects are actually not completed, but never mind that).
So here we can see Arduino board with led dot-display (this is actually a twitter scroller) which was placed in a mold and polyester resin was poured into it, onto the electronics. This is a very good way of packaging electronic devices especially when we want to protect our work from copying. In that case, resin should be black and it would be very hard to get to the PCB without damaging the components. By the way, happy Friday the 13th to all of you paraskevidekatriaphobics.
Source: davidnin1
NOV7
Timer for PCB exposure box with ATtiny2313
When doing more than one thing at the same time it is very easy to lose track of time. Exposing PCBs to UV light is delicate work and overexposing will result in, well, you know what.
Exposing is usually done with UV fluo-tubes but compact fluorescent lamps are also safe way to go and result in excellent PCB quality. Housing for the exposure system shouldn't be a problem because those old broken PC scanners come very cheap. The only thing missing here is the timer to turn off those lamps after pre-set (experimentally determined) time, but this also is not a problem any more because this solution with ATtiny2313 is excellent!
NOV6
Make arduino image scanner/sequencer
Here is a cool project for all of you Arduino lovers (not me, by the way). Even if you are not into Arduino or electronics per say, you might find this little thing interesting if you are into music or strange music instruments.
This here is actually a piece of hand-held hardware designed to create music by scanning a provided image or a drawing. The scanning sensors are LDRs (photo-resistors) and their values are read by Arduino with A/D channels. Those values are than converted to MIDI notes and music is born. This device can also be used as a scanner to scan images with very low resolution.
Source: Gijs Gieskes
NOV4
Voice powered crystal controlled radio transmitter
In case you have missed this before (I sure have) here is a radio transmitter that doesn't require any power source. Well, at least not any classic power source like batteries.
This radio transmitter is powered by the operator's voice alone! The speaker connected to the device converts audio signal to low voltage at the end contacts. Naturally, amplitude of the generated voltage corresponds to the amplitude of the speaker's voice, hence making this an amplitude modulated power source. This power source is used to power the high-level DSB modulator/crystal-controlled RF oscillator. The interesting part is that the range of this transmitter is around 160km/100miles!
Source: El Silbo
NOV3
Spectrum analyzer for 2.4 GHz band
The spectrum analyzer can be described as a frequency-selective, peak-responding voltmeter calibrated to display the magnitude of an input signal. Spectrum analyzer is not a power meter, even though it can be used to display power levels. In RF (telecommunications) spectrum analyzers are used to determine occupied bandwidth and track interference sources.
Spectrum analyzers are not cheap devices and here we will see a DIY RF spectrum analyzer for 2.4 GHz. It is based on Cypress CYWUSB6935 RF radio-module for 2.4 GHz which has one key component: internal RSSI meter (registers) that measure receiving signal's strength on selected frequency. This chip is directly connected to LPT port of a PC that runs plotting software that is built in Qt so it is available for both Linux and Windows. This is very useful tool to test WiFi channel occupation!
Source: Jason Hecker
NOV2
Color-changing halloween pumpkin
Halloween is behind us but it's never too late to scare people off with some crazy invention.
This is a remote controlled LED pumpkin. Channel buttons 0-8 on the remote toggle the colors of built-in LEDs inside the pumpkin. Button 9 activates the "angry mode" that flashes red LED for a few seconds. In the "angry mode" there is also a vibration motor implemented in the top cover, but it doesn't seem to shake that well. It is based on PIC18F2550 microcontroller with built-in USB bootloader which is a pretty large overkill for this project.
