VoltLink Shelly Adapter Test Jig | Voltlog #426

Welcome to a new video it’s been a while since I’ve done a project video on the channel and it’s not that I’ve not done any projects, I’ve designed lots of things this year it’s just that they’re part of my consulting business, under an NDA so they can’t be shared.

You may be familiar with the VoltLink, the usb to serial adapter that I designed a while ago, it’s quite popular on my Tindie store with lots of orders coming in and for good reason if you ask me, this is an awesome, reliable usb to serial adapter. To extend its functionality I also created this Shelly relay adapter which can be used to flash shelly relays, in a safe and reliable way by also powering the relay during the flashing procedure so you don’t need to have it connected to mains.

If you would like to order a VoltLink, you can find these on my Tindie store, there will be a link in the description of the video so check it out.

So far I haven’t any issues, not one single module with problems and I’ve probably made several hundreds of these. It’s a pretty simple design in terms of PCB, the components are 0603 so there isn’t much that can go wrong but recently I’ve started thinking about testing these.

Now the topic of test jigs and testing electronics in general can get pretty deep, especially if you need to implement it in the manufacturing process and keep track of the test results in an automated fashion but for hobby level it can be much simpler.

For example, depending on the number of units you manufacture, you can also skip testing all together, because if I sell 100 boards and 1 of them ends up defective, I can live with that 1 failure rate and I can cover the cost of shipping another board to that customer and all of this with zero resources wasted testing these but at the expense of one unhappy customer who needs to wait for another unit to be shipped.

So mainly for me that was the main factor for wanting to test these, to avoid having unhappy customers that might end up getting a bad unit. And I don’t really need to test for all of the things working, I just need to figure out if I have a working connection from the USB side all the way up to the shelly relay  and also verify that the path can be used to communicate over serial and toggle the reset lines.

This kind of test would eliminate for example a lot of the most common issue like soldering problems with the USB Type-C connector or with the QFN chip, or with the PCB copper layers, or with the JST-SH pigtail connecting the adapter board, or soldering issues on the small adapter board so all of these would be eliminated.

So here is what I came up with, a series of 6 total shelly adapters, chained together in series with an ESP32 at the end of the chain. I would be connecting a VoltLink at the start of the chain, UART signal would then go through 6 of these adapters, connectors, pigtails and it would end up at the ESP32 side for either flashing the ESP32 or writing a small test firmware that would just communicate over serial to verify the whole chain is connected correctly.

Best Upgrade For The Best Hot Air Station | Voltlog #422

Welcome to a new Voltlog, today I’m gonna be showing you what I believe is the Best upgrade that you can do to your Best 863 hot air station and if you remember Voltlog #256. That’s where I did a review of this hot air station, been using it ever since 2019, so that’s about 3 years of service so far, it’s been working great but with the obvious downsides of having this touch screen panel for settings and with the annoying buzzer that you cannot turn off from this standard interface. I mean it takes a lot of button presses even for a simple temperature adjustment and it’s beep beep all the way for every single step.

Well it turns out that someone thought enough is enough and designed a replacement control panel for this station, one that offers a more classic input method through potentiometers for the most important parameters temperature and air speed, offers control over the buzzer but still keeps the touch input if you need to alter any of the other settings and all of this can be ordered as a kit from Tindie which is pretty awesome if you ask me.

If you are interested in ordering your BST-863 hot air station or the upgrade kit which I highly recommend you get for the best experience with this station There will be some links in the description below the video so check them out.

You have two options when ordering this kit from tindie, you can either get it as a KIT which is what I have here or you can get it fully assembled for an extra $10. The Kit version comes with a PCB that has all of the SMT components fully populated but there are a few through hole parts that you will need to solder yourself. I think the author has done a really good job at packing and organizing the different components, Even the resistors come on this little card that shows you where they should be positioned on the PCB. The kit also includes all of the required mounting hardware as well as a sticker for the front panel potentiometers. The package was shipped from Portugal and it got here pretty fast. In fact I’ve had this on my desk for a good while, i’ve just been very busy and unable to install it so far.

VoltLink revD USB Serial Bridge & ESP32 Programmer | Voltlog #414

Ever since I’ve started offering the option for the Shelly programming cable, lots of people have ordered one because it makes the job of flashing an otherwise dangerously mains connected relay very safe by not having to power it from mains, but just supply it with DC power from the VoltLink itself.

But this video is not about that, it’s about the latest revision D of the board, the changes that it contains and some future plans.

So as you may have noticed there is no power LED on the VoltLink and to be honest for my personal use case I don’t really need one but I do understand people that want a power status LED so that they get a quick glimpse of whether the board has power or not.

Personally I think that because the VoltLink is so reliable in operation, the power LED is redundant but I do remember the times when I was using other cheap usb to serial adapters, there were the occasional issues with the micro usb connectors failing, with the on board chip failing, so it was nice to be able to see that you still got power to the board at least. Nonetheless, I added one to the new revision, placed it right next to the USB connector.

Now because I added these two extra components to my schematic, the LED and the resistor, I decided to switch to a resistor network to replace 4 x 1kilohm resistors with a single package to further optimize my BOM cost and DFM.

Another small change I did was to bump the 4.7uF decoupling capacitor on the USB to serial chip to 10uF because I was already using that value at the output of the voltage regulator. This once again, optimizes my BOM for using less parts as this will become important later.

And while I was revising the PCB, I also switched to these nice labels created with the Kibuzzard plugin for Kicad. No extra functionality because of these, but they do look nice.

USB Type-C Power Delivery The Easy Way! | Voltlog #411

You would think that implementing USB Type-C Power Delivery protocol on your upstream facing port  is a difficult task and if I would ask you if you can also support Qualcomm quick charge on top of that, the issue is even more complicated and you would probably be right to think so if you wanted to implement all of this by yourself but luckily you don’t have to, because there are dedicated chips that can do all of this and in this video I’m gonna show you how to use them.

So recently I started working on a project which needs USB Type-C Power Delivery input for negotiating 5 and 12V, it would be nice to also support Quick Charge, I basically need the capability to power my board from a standard phone charger with either Power Delivery or Quick Charge support. This will be an open source project, but I’ll talk about it in a future video after I build the first prototype.

Now to understand more about USB Type-C and the different power roles like Downstream Facing Port, Upstream Facing Port or Dual Role Port I suggest you check out this neat application note from TexasInstruments which is called “a primer on USB Type-C and Power Delivery” I will put a link to this in the description below and if all of this is new to you, it will help you understand how things are organized under USB Type-C.

What I need is the ability to sink up to 3A with 5V or 12V selectable voltage levels into my board, so that fits under an Upstream Facing Port definition and I wasn’t going to start implementing the power delivery negotiation protocol, it’s just not worth the effort when there are chips, specifically designed to do that. After a bit of research I have identified a company named Legendary Technologies from Shenzhen,  they seem to specialize in building these chips that provide USB Type-C negotiation for various roles. I have contacted them and I’ve been in touch with one of their applications engineers, they’ve been very supportive and have provided me with samples and support for implementing their chip which is very nice. I appreciate that kind of support and it helped me decide to use their chip in my design.

Expand your GPIO! PCF8574 & MCP23008 | Voltlog #409

Welcome to another Voltlog, in this video we’re going to take a look at an easy way of adding more GPIOs to your project because if you’ve been tinkering with electronics at some point sooner or later you’re going to need more GPIOS than what’s available from your microcontroller.

Sometimes manufacturers do offer a higher pin count package with more GPIOs with approximately the same CPU inside but in the case of an ESP32 module for example, that’s all you get and if you need more than you are out of luck as far as options from the manufacturer. And even if the manufacturer does offer a higher pin count option, those are usually more expensive and given the current chip shortage that we’re going through, they might not be available for purchase.

I had such a need recently for a design of mine so I decided to do this video to show you an option that you can use for expanding the GPIO capability of your circuit. In my case it was the ESP32 thermostat valve controller circuit, which makes use of pretty much all of the available GPIO so if I wanted to add some extra output channels I have no more available GPIO.

Luckily this problem is not new, it has been around since the introduction of digital processors so there is a very convenient solution to our problem in the form of GPIO expanders. They can come in many shapes and sizes but the key feature is that they usually take a serial input which means a low pin count for the input and they provide a number of different outputs depending on the package. So here is for example the datasheet for a very popular GPIO expander chip, this is the PCF8574, the datasheet is from NXP but this is manufactured by different companies and this is a big plus because there is a higher chance of finding these in stock.

Global Chip Shortage Solution Or Maybe Not? | Voltlog #406

Welcome to a new Voltlog, In this video I’m gonna show you one potential solution if your design uses a part that you can’t source anymore due to the global chip shortage but also the pitfalls of using this method in the case of a dc-dc converter. Please keep in mind that actual price per unit or stock availability will vary between the point I started working on this video which is a couple of months ago, the actual time when I publish it or the time that you are watching it.

Let me start with providing you a bit of context here, this is the CanLite, an ESP32 based design that I sell on my Tindie store. It’s a CAN development board, it’s got a couple of high side switches, a CAN interface, a powerful processor with Wifi Capability and an automotive rated DC_DC converter to allow the user to power this from a car 12V system.

The DC-DC converter chip that I’m using is the Texas Instruments LMR14006 and I’ve been pretty happy with using dc-dc controllers from TI over the years because they generally perform really well and they have good documentation and design resources available.

Now as you all know the chip shortage has not been kind to us and as a result I can’t find this chip anymore. If we go to Octopart which is like a search engine for electronic components, we see there is no stock with any of the major distributors for the particular part number that I was using LMR14006XDDCR. And don’t get your hopes up with Winsource or Cytek, these guys just list stock for stuff that they don’t have and even if they have it, it’s not worth going through them unless you have a high volume.

Is A Genuine JBC Station Better Than A Clone? | Voltlog 401

If you are a subscriber of the channel you’ve seen me review this Best soldering station in Voltlog #340 This is a clone of a JBC station and I’ve been happily using this station for the past year as my daily driver. But is this very different in terms of performance or build quality from a genuine JBC station? In this video we’re going to answer that question because thanks to welectron.com I was able to acquire this JBC station for a 50% discount so if you are looking to get yourself a new soldering station please check them out, they have a pretty good offer, a link will be in the description below.

So as you can see these two have a fairly similar size & shape but upon comparing their weight I discovered the JBC original is 2.5KG while the Best station is 3KG. The soldering hand piece which is model T245A is fairly similar for both units if not identical, you don’t get the soft foam padding for the BEST but otherwise very much the same plastic, same silicone wire, same length. However as you may know, the handle piece from my BEST station failed at some point soon after I got it and I did an autopsy in Voltlog #387.

I’ve replaced the failed handle with a genuine JBC T245 which I got for like 20EUR from ebay as new old stock. So generally speaking while the two handle pieces are almost identical, you can expect lower quality control on something like the BEST and you might be unlucky enough to get a bad handle that will fail at some point like mine did. There is ofcourse a bunch of happy users who didn’t have this issue but the bottom-line is, there is no guarantee on the quality control.

IV-18 VFD Clock Kit Assembly | Votlog #388

Welcome to a new Voltlog, in this video I will show you how I assembled this VFD tube based clock, I like the looks of this clock very much it’s kind of steampunk type of style and because this is a kit, it’s widely accessible to anyone, you don’t need very specific tools to get this assembled and I believe anyone can put one together. As a bonus this clock, although it doesn’t include one in the kit, it can support connecting a GPS receiver for syncing the clock and on top of that you get a remote control so you can control it from a distance which is pretty neat if you ask me.

I got this particular kit from banggood and you’ll find a link in the description of the video if you are interested in getting one, I think it’s important to watch this video before you start the assembly because you might find some inadvertencies between the provided user manual and the actual kit that you receive.

This is what you will receive in the box and this is pretty much all needed for a functional clock, if you are missing the stuff shown here you might be unable to complete your clock build. Like I previously said the GPS module is optional but depending on where you live you might not get GPS reception in an apartment building for example so it might be useless to you anyway.


Best T245 JBC Clone Handle Teardown | Votlog #387

Welcome to this short Voltlog where I plan to take a look inside this JBC clone soldering iron handle. This is the handle that came with the Best-933B JBC clone station, I reviewed this in Voltlog #340 a year ago and I’ve been using this station as my main soldering tool for the past year. I plan to do a future video where I tell you my opinion about this station after 1 year of usage but the short story is obvious due to the fact that it’s my main soldering tool, I like using it.

The soldering handle that I received with this station had a problem since day one, first use, when I inserted the soldering tip into the handle I could kind of feel like there was something wrong, there wasn’t a clear stop when pushing it in and after powering on the station the screen was flickering, it couldn’t read the temperature and this cable got hot which is a good sign that something is shorted inside the handle.

I’m not sure if I am to blame because I might have pushed the tip too hard into the handle the first time. It’s also possible that it had a factory defect inside the handle.. Other users of this station don’t have this problem but long story short ever since I got it, I had to be really careful when switching tips because I needed to seat the tip very accurately in a certain position, otherwise it would short circuit causing the station to go crazy.

New Lab, New Voltlog Electronics Workbench | Voltlog #367

The most important part of this lab is obviously the workbench and this is something that I designed myself, I guess I can call this the Voltlog Workbench Design, it’s 2m wide with 80cm deep. The working surface comes out at about 95 cm from the floor. It sits on these adjustable feet but I haven’t even leveled it so far. Thanks to my friends at Welectron.com my working surface is protected with these nice premium ESD Mats. They are 100% and phthalates free, no bad smell, Heat and solder resistant, Chemical resistant, two layer ESD bottom side is conductive, top side is dissipative and they have this nice anti-reflective surface finish which is very comfortable to work on. I went with gray because it works best as a background for video shooting but you can opt for Blue as well. I’ll put a link to these in the description below, I highly recommend Welectron for their services & customer care and I highly recommend these ESD mats they are top quality.