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.
Category - Electronics
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: 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