The digital multimeter is one of the most important tools in the electronics professional’s and electronics hobbyist’s toolbox, so much so in fact that electronics aficionados usually have more than one. However, digital multimeters are used not only by electronics enthusiasts but also by other professionals such as car mechanics and electricians, who often have slightly different needs with respect to multimeter specifications. As a consequence, the humble digital multimeter comes in a variety of different flavours which cater to the needs of different professions. Therefore the electronics hobbyist needs to know beforehand what specifications are appropriate for electronics work, and what he or she should be looking for when buying a digital multimeter. So what's the best multimeter for electronics work and what should a newly-minted electronics hobbyist be looking for in their new digital multimeter? Let's try to answer those questions.
Weather for us Brits is a big part of our daily lives - not surprising since our weather can be often so unpredictable. Many of us too are fascinated by the weather, its unpredictability, its variability from year to year, and with global warming entering into the equation and making weather more extreme, it is only going to get all the more wild and interesting. That is why more and more of us are getting into monitoring our local weather not only to make better decisions in our own personal lives but also to keep track of how our weather is changing over time. One of the weather monitoring tools that is within almost everyone's budgetary reach is the wireless home weather station, which usually consists of a central display unit with one or more wireless sensors sited around and outside the home. Of course, as with all electronic gadgets these days, the humble weather station exists in a plethora of different makes and models, each sporting a range of different features, making the choosing of the best weather station for the home a difficult and confusing task. That's why here at Approach Labs, we have taken the time to look into the variety of features that different home weather stations offer, and to compare the popular ones that are available to consumers here in the UK to help you decide what's the best wireless weather station to buy for your particular home.
Summary: The objective here was to make a USB breakout board that incorporates the hardware required to implement the mostly-software-based USB protocol, V-USB from Ojective Development. The completed V-USB module is able to be connected to a range of Atmel AVR® microprocessors involved in various projects at the breadboard stage, obviating the need for additional USB circuit components be added separately to the project breadboard whenever USB functionality is required. The use of V-USB where the USB protocol is incorporated into the main project AVR microcontroller also replaces the need for a dedicated chip to handle the USB protocol.
Summary: When trying to build an electronic device based around a microprocessor, it’s useful to have the microprocessor itself send back updates as it executes its code so that one is able to debug any problems with the device. The microprocessor type that I invariably use is an Atmel 8-bit AVR (most often the ATmega168) so this write-up will be focused on getting that system to work. So how do we get these debugging messages from the AVR microprocessor? One way is to use the USART capabilities of the AVR to communicate with a computer via an RS-232 serial connection. Although, the RS-232 serial connection represents an older way of doing things, it does work just as well, for our purposes anyway, as more modern methods, and is especially appropriate if you have an old unused computer lying around that could do with a new reason to live! Read More
Summary: If you are the owner of a Taotronics car phone holder and, like me, you like the design and functionality it provides, but dislike suction cup attachments in general and the fact that it occassionally falls off the windscreen when the weather is warm, then check out this project where I convert the suction cup mount into a permanent mount for my car’s dashboard. Super-steady and no more messing around with the unpredicatbility of suction cups. Looks good too, although would have preferred it in black! Read More
Summary: The objective with this project was to create a visual signal on my treadmill that would alert me to when someone was ringing the front doorbell. Why a visual alert? Well, because I invariably have music blaring out of my in-ear headphones when I’m running and between that and the noisiness of the treadmill itself, I have, in the past, missed the delivery guy knocking at the front door. It is so annoying to have to go on a treasure hunt just to recover parcels that I could have easily received myself if only I had known that the doorbell had been rung. The final design involved a large red flashing LED to get my attention, controlled by a 556 timer chip (which is two 555 timer circuits in one package) and wired through internal house wiring to the doorbell. The enclosure housing the device was designed to fit into one of the bottle holders on the treadmill display console. Read More
Summary: The idea here was to create a temperature sensor that could easily be connected to an Apple Mac computer and have it display its readings inside an OSX application. More a demonstrator than anything someone might actually use in the real world, but who knows, maybe someone out there has a practical need for such a contraption… Read More
Summary: A number of the device creation projects detailed on this website use the Atmel AVR microprocessor as the CPU or the ‘brains’ behind the device. However, before one can build any of these devices, one has to be able to get the firmware code on the AVR itself. There are a number of ways to achieve this and the method descibed here is probably not the most efficient way, but it does tend to be one of the less expensive ways of firmware loading and can also put to work some old equipment which you might have lying around earmarked for the trash heap. Read More