Low budget feature rich multimeter

In my opinion multimeter is a number one tool on every electronics engineering bench. There is no question that at least one multimeter should be reliable and rigid. They usually cost more but you can use it with confidence. In most cases one multimeter isn’t simply enough. Some measurements can engage even four multimeters and more. If you are serious about electronics, you need to have several of them. Not all of them should be expensive and top brand. Practice shows that mid-range brands perform pretty well and in some cases can offer additional features that you may find useful. Let’s look at $50 range multimeter OWON B35 which looks pretty attractive with all of its features and look. Neat thing is that it comes with Blue-tooth 4.0 connectivity enabling it to be used along with Android application. Continue reading

Multimeter hacked with talk module

Talking gadgets may be annoying, but sometimes they can be a big helpers. One situation – blind people. Voice messages can help make electronics useable. Another situation is when you can’t look at display due to complex task you are doing or you are in position when you cannot see it. Either way voice on devices might be useful. MastroGippo had a request to convert multimeter into talking one. He found out that there is no many multimeters on market that talks. Some of them are expensive, while other discontinued. Instead of struggling to find one he started hacking. He found that simplest and cheapest way is to play prerecorded sounds with Arduino. He stored number waves in to SD card. Another problem is number pronunciation in different languages. Luckily In Italian it sounds like like “hundreds” + “tens” + “ones”. So converting number to sound is easy. Other languages may struggle a bit (eg. France). After number is captured, an Arduino simple SDAudio library takes care of playing it. As housing he used cheep phone speaker that carries all… Continue reading

The Awesome and Cute AVR-based Programmable LED

Programmable LEDs are those projects that have been fully-programmed with numerous LEDs. In this case, the idea is to make the LED blinking sequence reprogrammable. Basically, the reprogramming can be easily done with light and shadow. Today, you’re giving the chance to build an awesome yet cute AVR-based Programmable LED. Before you’re building a programmable LED, you must first prepare the following materials: Two 1K resistor A Light Dependent Resistor A Low Current LED (1.7V, 2ma) An Atmel ATtiny13v, 1KB flash RAM, 64 Bytes EEPROM A CR2032 (3V, 220mAh) Soldering iron and wire Breadboard AVR programmer 5V power supply Multimeter The reason why the ATtiny13v is used because this version is able to run at 1.8V. In this case, it is possible to run the circuit with a very small battery. If you want it to run for a very long time, you might want to use a low current LED, which is able to reach full brightness at 2ma! Continue reading

The Hypersensitive Digital Thermometer

Want to have a hypersensitive digital thermometer, but you have no idea where to start? Well, then you should spare few minutes and read on this article… Nowadays, it’s quite easy to build an inexpensive and accurate digital thermometer. With the easy availability of digital multimeters and integrated circuit temperature sensors, it makes the whole process even easier than before! For your information, you’re about to build a digital thermometer that based on PIC16F877 microcontroller, alongside with the temperature sensor LM35DZ and MAX232 IC. You can view the temperature measurements on a computer program, where it can monitor the state of COM ports of a PC. Continue reading

The Innovative Multimeter For Measuring Power Supply Unit

Do you ever think it would be better if you have a multimeter, which can be used to measure output voltage and current in a PSU, where the current sense shunt resistor is connected in series and still has load at the negative voltage rail? If you did, then you must be interested on today project! The multimeter that you’re going to make today will requires only one supply voltage, which it can be acquired from the main PSU. Therefore, an additional function of the multimeter is, so it can control an electric fan will be used to cool down the main heatsink. As a result, the power threshold at the fan switches on can be easily adjusted by simply using One Touch Button Setup! Furthermore, you can use the Multimeter with measurement of the amount of electric charge, where the main source its comes from PSU to charge your RC Li-Pol cells. The PSU is a very convenient tool, as the constant-current, constant-voltage charging is easy to archive. As a result, the charged capacitance indicator will give possibility to… Continue reading