This thing is not like our regular basic electronic component. This is practically a consumer electronic product, although looks like Arduino LED clock module – it is fully plug and play. We can use that TM 1637 7 segment LED display with Arduino to create a digital voltmeter. But that is not in this guide. You can not use this thing with Arduino. Not everywhere we can use a Multimeter to test battery, like inside a running car. Here is some information and how to use cheap mini DC digital voltmeter which can be useful for Car, checking Battery, DIY electronic works, etc. You can say this is a Mini DC Digital Voltmeter buying and usage guide. Made in China things usually have no guide. At that price they sell useful things, it is funny to ask for a properly printed guide.
Details About Mini DC Digital Voltmeter
Red coloured display costs least, blue coloured costs highest. One type has 3 wires, another type has 2 wires. 3 wire model are good to select when you will not permanently fix it somewhere like in car. 2 wire model is good for situations where you want to fix forever. Next is whether mounted on a small plastic panel or not. Without panel, only the PCB with display, 3 wires costs only $3. That one with small plastic panel probably intended for using on car’s dashboard. You will find them on e-commerce websites like Amazon, Ebay. In case you want it to use as a meter, then put inside an enclosure, use a battery casing and ON-OFF switch. I noticed an image with an innovative idea for the old cars with an empty place below those single DIN stereo (they were intended to keep audio cassettes, audio CDs). The below graphics is self explanatory of how to connect and use.
Can I Create This Mini DC Digital Voltmeter As DIY Project?
It is possible to create a 0-5V voltmeter using Arduino with medium accuracy (~50mV) with either common anode multiplexed seven segment LED display module (E1-3056ASR1) or TM 1637 seven segment LED display module. In such plan, you possibly want to use push buttons and more sensors like to measure temperature.
Another way is to use PIC16F877A Microcontroller.
Similar LED AC 60-500V Digital Voltmeters also available at similar price which can be used on every room’s switch boards.