Voltlog #268 – RaspberryPi 10 Inch IPS HDMI Monitor 2560×1600 2K

Welcome to a new Voltlog, it’s product review time again, this time we’re taking a closer look at a 10 inch monitor with hdmi input. This is the box it comes in, the monitor has a resolution of 2560×1600, that’s about 2K resolution in the scheme of things, 300 pixels per inch density, 16:10 aspect ratio which I’m a fan of. My desktop monitor is also 16:10 and it works so much better for everyday activities but especially if you are doing any CAD design work. It’s an IPS panel so we should have good brightness, contrast and colors, it’s rated at 400 candela per sq meter. We also get built-in speakers and the HDMI supports video & audio so you should be able to get video and sound through the HDMI cable and that’s useful because we have built-in speakers on the monitor itself.

Voltlog #214 – How bad is a fake apple lightning to 3.5mm audio adapter?

Welcome to a new voltlog, today we’re taking a look at these lightning to 3.5mm audio adapters that you have to use ever since apple removed the 3.5mm jack on the iphone. So you know the story, apple removed the jack and said it’s because they will free-up space inside the phone and it makes it more waterproof but if you ask me that’s bullshit, they removed it to force people to buy bluetooth headphones. But anyway we won’t go into that, this video is about the adapter that they now give people to still be able to use the 3.5mm jack for audio.

This made me wanna take a closer look so here are the two adapters, the plan is to connect a 3.5mm jack, this will provide me with some contacts where I can probe with the oscilloscope. I’m gonna generate a known constant waveform from an app and we’re going to measure that and compare between the two adapters.

Voltlog #93 – Bluetooth Receiver Weekend Update

This week I build a DIY bluetooth 4.0 audio receiver. I used the CSR8635 bluetooth module, a recycled lithium battery cell that I got out of an old laptop, a TP4056 battery charging & protection IC and a DIY PCB I made myself.

Here are links to these items if you plan to build one yourself:

Or you can just buy a ready-made bluetooth receiver.


Voltlog #78 – 2x25W Bluetooth 4.1 Stereo Amplifier TDA7492P

In this episode we are going to build a bluetooth speaker amplifier based on the TDA7492P class D audio amplifier coupled with a Bluetooth 4 module. We are not actually going to build the amplifier module because we can get that from China, very affordable, it only costs around $12 shipped which is way less that it would cost us to buy the bluetooth module and the TDA7492P individually not to mention the cost of fabricating a PCB of this size.

So we are actually going to use this module and build the final product with a nice enclosure and a suitable external power supply

Here are some links for the parts used to build this project:

Wiring diagram below:

Voltlog #37 – InTheMail

Hi and welcome to a new InTheMail, this time we have allot of items to look at and some of them were ordered 2 or even 3 months ago but due to the postal service madness that happens every year during holidays they arrived a bit late.

The video is split across two parts to avoid making it too long so make sure you watch both parts.