Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Weird way of testing multiple things with Arduino

If you are nerdy enough, then such devices would look great in your collection. Ctopconsult have build so called Arduino monitor/tester. It has a monster load of LED indicators and other things that enables to test and control multiple things from a single board. There is a long list of supported sensors and devices. Each input and output has a LED indicator. It is Arduino compatible as a shield and can be powered from either 5V or 3.3V. As separate attachable module there also comes LEMO I/O, shake sensor, TMP36, microphone, piezo speaker. Built in options include button, toggle switch, two pots, seven segment display, small coil voltmeter, piezo speaker, 4 digital outputs to open-drain MOSFETs, couple opto-isolated I/Os, couple I/Os through LEMO coax-connector, reed relay, mercury shake to digital input, LDR, NTC, etc. Once front panel is one, everything seems pretty well organized and obvious with its text labels and numbers. Continue reading

Dual digital thermometer with I2C interface

Stand alone digital thermometer is very easy to build – especially when microcontroller has an ADC interface built in. Tuxgraphics has posted a new cute thermometer project which uses two NTC temperature sensors. They are cheap and quite precise for most hobby projects. One problem that they are non linear. But this what microcontroller is for. Some basic semiconductor physics and math and characteristics is straighten. Device reads temperatures from two sensors – inside and outside. Both temperatures a displayed on standard HD44780 compatible display and additionally information is sent to PC via I2C interface. Why I2C and not UART? It helps to save the hardware like MAX232 and multiple capacitors. Having connectivity with PC is great – you can always call a small GUI to see current temperatures or by running cronjob you can collect a long term statistics or even publish on the web. Continue reading