GSM module. Your “Mailbox” is calling you

Saturday. Output. You don’t want to go anywhere, and you don’t want to, even check the availability of the treasured notice in the mailbox. And suddenly a notification will come, and having found it on Sunday (and the day off at the post office), you have to wait even before Monday. How to avoid this unnecessary wait? Read More

UNI-T 612 LCR Meter

Greetings to you reader muski. This review will focus on the UNI-T 612 bridge meter. Welcome to.
It’s worth mentioning right away that this devicehighly specialized, for most readers and for the author is not needed. Most people live well without multimeters, and those who have a multimeter can say, “I have a good multimeter with an automatic gearbox and it measures both resistance and capacitance, why do I need LCR?” A monitored device performs measurements differently from multimeters and has higher accuracy + special measurements. Read More

MAFAM XP209. 11k mA * h Chinese power bank with dialer function

The story of how I bought a power bank with a phone function.
A tempting thing, I thought, looking at him. To get lost in the forest, in a train without electric oxygen or in a summer house, feed a hoarse column - very good weight.
I ordered it. I paid. I waited. Got.
At first glance it looks stern, weighs solidly, in the direct thought of a “brick” that can be beaten off by gopniks. Read More

PCF8574P: connecting buttons to Arduino via I2C bus or Luke Skywalker strikes

I decided to make a text operator panel (HMI) and connect it via the “square” I2C bus to the Arduino. For this, he developed a 5-button keyboard board based on the PCF8574P chip.
PCF8574P is a port expander, DIP package, works on the I2C bus. I bought a batch of two such chips for $ 0.94 with free shipping from China, so one thing costs $ 0.47. Read More

HBS760 Bluetooth Headphones

Wireless headphones / headset. I decided to order myself such a form factor, because I often ride a bicycle in a helmet. My previous Qumo Concord, dressed on my head, did not fit under the helmet in any way). The same ones hang on the neck and do not interfere.
They walked for 3 months. I ordered 3 pieces of different colors, since the seller has a choice of colors. Read More

TDS meter - measure the hardness of water from various sources, including natural ones.

Hello, today we will talk about stiffnesswater measured using a TDS meter or salimeter. This device has already been repeatedly viewed on the site, but since I live in the foothills of the Caucasus, there was an idea to go camping with this device and measure the water hardness in a mountain river, mountain stream, forest spring. Read More

esp8266 + ws2813 = new year mood

Reading reviews on Muska, I found out abouta wonderful thing is the LEDs with pixel addressing, and I also saw an interesting application of the tape LEDs with pixel addressing. It was decided to build something similar, but, let's say, on the basis of something more promising and interesting than the arduino from the sav13 review, and not as difficult as yurok did. Read More

Low self discharge PKCELL AAA NiMH 850mAh batteries

AAA low self-discharge batteriespkcell production with a capacity of 850mAh, much cheaper than eneloop. By kat video with an overview, not enough text, and a picture of measuring the capacity with LaCrosse 9009. I bought for $ 13.99, i.e. at $ 0.87 apiece. In short - you can take it.
A few months ago, I already purchased PKCELL LSD AA 2200mAh NiMH batteries, two sets of 4 at once, and during this time they showed themselves only on the good side. Read More