Voltlog #161 – How To Assemble SMD Parts

In this video I’m gonna show you 3 methods to solder SMD parts but before we get to the actual methods I think it’s best to talk about the type of solder to be used. And there are two main types of solder that you can use, that is leaded or lead free solder. If you are doing prototype work it’s best to stick with leaded solder or solder paste because it’s easier to get right, it has a lower melting temperature. If you are doing production work, you plan to sell those boards, than you might be forced to use lead free solder to be compliant with the regulation.

Here are links to the items shown in this video:

Voltlog #154 – Making My Own Trezor Crypto Hardware Wallet

In this video I’m gonna show you how I build my own Trezor hardware wallet. If you would like to support the voltlog channel checkout the donations page where you will find my paypal address or different crypto wallet addresses.

If you encounter this error while trying to compile trezor firmware:

Traceback (most recent call last):
 File "nem_mosaics.py", line 6, in <module>
 from google.protobuf import json_format
ImportError: cannot import name json_format
Makefile:121: recipe for target 'nem_mosaics.h' failed
make: *** [nem_mosaics.h] Error 1

It can be fixed by installing googleapis-common-protos package like this:

sudo pip install googleapis-common-protos

This fix was posted in the comments section by a viewer, I verified and it works.

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 #47 – ICL8038 Frequency Generator Kit Assembly

Today we’re going to be assembling this frequency generator kit based on the ICL8038 which I got in an earlier InTheMail episode. The ICL8038 waveform generator is a monolithic integrated circuit capable of producing high accuracy sine, square, triangular, sawtooth and pulse waveforms with a minimum of external components.

Voltlog #45 – Multiple Rail Power Supply Kit Assembly

In this video I am assembling a multiple fixed rail power supply kit. This power supply works with a 5-24V input either through a USB mini socket or a dc barrel jack (2.5mm center positive) and at the output you get +12V, -12V, +5V, -5V and +3.3V. My kit was missing 1 small heatsink and one of the electrolytics was a different value than specified on the PCB.

Voltlog #42 – DIY 4 x 18650 Battery Charger

Today we’re going to be making a DIY lithium battery charger and more specifically aimed at charging 18650 cells. I sometimes take apart some of these laptop batteries to recover 18650 cells and I have a bunch so far that I kept. Every-time I salvage these cells I test them before deciding to keep them or not.

As you can imagine it takes time and I need to charge multiple cells at once. So I will be making a charger that can handle 4 x 18650 cells but the project is scalable and you can increase or decrease the number of cells it can handle according to your needs. As usual, links for all the items will be in the video description.