InTheMail | Voltlog #430

Welcome to a new InTheMail, the most popular segment hosted here on the channel. Not a lot of time has passed since our previous InTheMail but I have received a bunch of stuff that I would like to start using so I need to do this video.

I’m gonna start with a series of cabling products and the first ones are these higher quality braided USB Type B to various terminations. These two are USB Type-A to USB Type-B printer style cables but in two different lengths, braided finish, higher overall quality and I tend to use these for stuff like an older AVR MKII programmer, for my label printer, for my monitors which have a built-in USB hub, stuff like that.

Then because of modern devices which tend to include less USB Type-A ports but for guys like us who still use a bunch of peripherals, we still need to connect some USB Type-B peripherals to the new USB Type-C ports and it’s nicer when you don’t have to use adapters or USB hubs for that. So I got these USB Type-B to USB Type-C cables for plugging directly into USB Type-C ports, also braided style.

And this guy is just a short, braided style, USB Type-A to USB Type-C which lately I use a lot of these guys because all of the pcb’s that I’m building feature USB Type-C ports and I typically need to connect them to a USB HUB which sits right on my desk so I need a short USB cable. I typically get these from Baseus but this time I tried another company and I quite like what I’m seeing. Nice construction here, lots of room to grab on this connector when inserting into a socket. Same as always there will be links in the description below to all of the items shown in this video.

Also in the cabling department I needed some of this thicker 18AWG UL1015 wire for various wiring jobs working on prototypes on my electronics workbench. Now for 20AWG or 22AWG I typically recycle those out of old ATX power supplies wiring, I feel like I’m doing the planet a service when doing that by preventing them from going to a landfill but for the thicker 18AWG, those are typically not present on an ATX PSU so I ordered a lot of these, 5m per each individual color so these should last me a good while.

This is your standard 2.5×5.5mm dc jack connector with 2m of white cable which has markings that say 2×0.5sq mm which would make it okay up to 3A but just to stay on the safe side I would probably use it only up to 2A in practice. Something like this would be very useful if you are a power adapter with the wrong plug, instead of just replacing the plug you could replace the whole cable if the power adapter can be easily disassembled. And that’s exactly why I got this, to replace the wiring on a 12V power adapter.

InTheMail | Voltlog #428

Welcome to a new InTheMail, the most popular segment hosted here on the channel. Lots of interesting good and equally bad products have been piling up in my special mailbag bin so let’s take a look at them.

I’m gonna start with an absolute garbage product, this smartphone telephoto lens which I thought is going to be great for attaching to my iPhone and shooting videos at let’s say a meter away from the subject but be really zoomed in, like when soldering on a PCB, I don’t want the tripod and the phone to be in my way. I got the 8X variant, because there is also a 12X I believe, I paid like $5 shipped for this and this was probably the worst spent $5 in recent times, this is absolute garbage. All I can get is a blurry image, I’ve tried removing the protective case on my phone thinking this might not be the correct focal length because of that but nope it doesn’t make any difference. Other users report similar things in the product review.. So please don’t order this crap.

I seriously don’t understand what were they thinking? Why did they make this and package it?

Next up I got one of the newer GPS modules from China, this is the ATGM336H which presumably is the part number for the original module Zhongke Micro electronics, but this particular one is rebranded as AiThinker GP-02. Comes with a ceramic GPS antenna so it’s good to go. The SoC used inside this module is the AT6558 and it supports a variety of satellite navigation systems, including China’s BDS (Beidou Satellite) GPS in the US, GLONASS in Russia, GALILEO in the EU, QZSS in Japan and I think their main target is to replace ublox max series with something that is the same size, possibly same package but lower cost. I thought I’d give this module a try, keep it in my GPS modules bag waiting to be used in a GPS project. One mention though is that it doesn’t necessarily mean this particular module that I got from Aliexpress supports all of the functions.. This depends on the variant of the chip used inside the module because as the datasheets shows in this table it can have different config levels. A link for this will be provided in the description of the video.

Next up I have a few different types of insulating washers. These red ones are M3 and M4 size paper type insulating washers, while the black ones are just plastic nylon insulating washers. Both of these can be great when you want to achieve some level of mechanical and electrical insulation when you have screws holding down a pcb and you might have some PCB tracks going too close to the screw hole for example. If possible such a thing should be avoided from the PCB layout stage as mounting hole footprints should have keepout areas corresponding to the size of screw to be used but if you end up with tracks in that space, a small insulating washer like this will save the day.

Next up I got one more set of these Adhesive cable tie mounts, I’ve shown these before, they have some adhesive backing and then they are theoretically reusable because you can clip and unclip this plastic belt. Because of that they can be really handy for cable management. Not sure if this adhesive backing is really 3M, it might not be and the effect of that is that these might come off at some point. Not that 3M is bulletproof, I’ve had genuine 3M cable management mounts that come off after a couple of months so it really depends on the surface type, how clean the surface was and the actual strength of the adhesive.

InTheMail | Voltlog #424

Welcome to a new InTheMail, the most popular segment hosted here on the channel. Lots of interesting gadgets have been piling up in my special bin so let’s take a look at them.

I’m gonna start the video with this small silicone mat, I’m sure you are familiar with these. I just wanted a smaller one that I could fit on the work surface of my microscope. This is my trinocular microscope, if you are a subscriber of the channel you’ve probably seen it before, I reviewed it in Voltlog #282 and I did a few upgrades since then on its video camera system. I sometimes do soldering right here, on this work surface so it would be nice to have a small silicone mat to help with that and I found this model on Aliexpress, it’s a good size for this purpose, just a little too thin for my taste, I expect this to bulge immediately under the action of the hot air gun but other than that, I think it should do the job and it was very inexpensive to purchase. Same as always you will find links for all of the items shown in this video in the description below.

Next up I have a couple of interesting display modules that caught my attention while casually browsing through the recommended products list. This one is a 1.69inch TFT display with 240×280 pixels resolution so it’s a fairly densely packed panel, based on the st7789v2 controller IC. You can get this as a panel or as a breakout module like I have here. I opted for the breakout panel so that I could easily test this and hook it up to a dev board. It seems like it’s wired for a SPI interface on this breakout board and I guess the main features of this display panel are its thin bezels left, right and top, you ofcourse need a little thicker bezel for the side where the flat flex is located, because there you have the driver IC, the backlight plus the bonding of the flat flex.

As you can see in this quick demo I prepared, it looks very nice, much better than your typical aliexpress 2 inch tft panel so I think we’ll be seeing more projects using these popping up on the internet.

The next display comes from the same company making these breakout boards, and it’s a 2.13 inch 122×250 pixels resolution, TFT white and black display based on the st7302 controller IC. They say it’s targeted for low power applications. I don’t think there is any backlight on this one so it’s a reflective type display. Interface is once again SPI and you can get this as a bare lcd panel or as a breakout board like I have here. I thought the format of this display is pretty interesting and once again I think we’ll be seeing some more projects using these popping up on the internet.

Next up I got myself another one of these cheap, compact side cutters, I’ve been using these for a while for various jobs, I recently gave one to a friend so I needed a replacement. They’re not the best quality but they’re decent enough and I like the form factor a lot. Useful for cutting off through hole component terminals but also for the small size wires and other miscellaneous stuff. Do yourself a favor and order 2 of these.

Next I got one of these which is like a rust cleaning fiber pen, the way this works is you spin this cap which pushes some fiber bundle through the tip of the pen, those are pretty abrasive and so you can use it to rub off superficial rust of small items like jewlery, watches, but what I thought this could be useful for is ofcourse electronics, PCBs, where you need to clean some burn marks or something like that. I’m not sure how long those fibers are, or how long this is going to last but I thought it would be a nice addition to my set of cleaning tools. Links for this are in the description below the video so check them out.

InTheMail | Voltlog #421

Welcome to a new InTheMail, the most popular segment hosted here on the channel. It’s been quite a while since the last InTheMail so a lot of interesting stuff has been gathering in my special bin.

I’m gonna start the video with these EVA hard shell cases in a rather small format, as you may be aware these come in a variety of shapes, sizes and colors, they’re inexpensive and personally I like to use them to store various bits of gear, test instruments in the lab but also to transport small PCBs, projects that I’m working on in my backpack without find out out at the destination that all of the through hole parts have been squished in the process. It just provides a nice solution for storing and carrying various items.

Next up I have a couple of GOPRO Accessories and I’m gonna start with these tether lines and they can really be multipurpose, that’s why I’m showing them in this mailbag, they’re made of steel, they come in different lengths and colors and they can even be used for minimal security by looping them around things and closing with some sort of lock, they feel pretty strong but you know it’s only going to work for honest people.

So I think I’ve mentioned this before, that I recently started kitesurfing and I wanted to get one of these kite line gopro mount because of the nice viewing angle that this provides on video, however, there is a big drawback with this, because it can potentially tangle the lines and as a beginner that’s something that I do not want to deal with, because it can put me in some dangerous situations so I’m likely not going to be using this until I have gained some experience on the water

And because I am using my gopro mostly on the water I got myself one of these gopro floating cases, it’s just made from foam, goes around your gopro, it’s bright orange and if you drop it in the water it will helpfully keep it floating while you search for it. This is an inexpensive accessory but one that could save your more expensive camera. As usual links for all of these items will be provided in the description below.

Next up, another item for my summer activities, I got these plastic tent stakes which I plan to use with this smaller UV and wind protection shelter that I got for beach days. The tent/shelter was delivered with those slim mounting pins which slide right out of the sand but these plastic ones which I recently got really work so much nicer. I’ve taken 3 out of the package and tested them this past weekend and you have to work a little bit to get them into the sand by this screwing action but they provide much better grip into the sand. I mean you can still pull them out if you wanted but it will require some force so I think they do the job just nice and on top of that they were really cheap.

InTheMail | Voltlog #418

Welcome to a new InTheMail, the most popular segment hosted here on the channel. It’s been quite a while since the last InTheMail so a lot of interesting stuff has been gathering in my special bin.

I’m gonna start the video with this lithium ion battery charger. If you remember this cheap cordless drill which I reviewed in voltlog 285, maybe you can remember that it had a pretty low cost battery charger which I sent to the DiodeGoneWild youtube channel for a teardown. So ever since then I’ve been charging this on one of my bench power supply units which is not very convenient because I can’t take it with me everywhere I go. So I’ve started searching on Aliexpress for a little more quality in one of these adapters and after many tries, I’ve found this model which doesn’t have any indication of being higher quality other than being different and slightly more expensive than other listings so I said why not give it a try, do a quick teardown to see how it’s built, maybe I can find something better that can also work as a recommendation for other people looking for something similar.

My next item is yet another Power supply unit, this time, it’s one that has all of the regulatory approvals and it should be of higher quality coming from meanwell. This is a 12V 2A, so 24W total, model number is HDR-30-12 and the main feature of this is that it’s DIN rail compatible and I plan to use this at some point to further expand my home automation project with some solenoid valve control. I’ve bought mainly to evaluate the quality. I haven’t yet decided if I should use 12V or 24V, also depending on the type of valves that I will be using but generally speaking 24V would be nicer because it could transfer energy more efficiently over the wires that I’ll be using. This is DC output so again, depending on the type of solenoid valve, those might require AC power so I might need a different power supply for that but when I bought this I was really thinking of using it with my servo project which needs DC power. Either way it’s going to be a useful power supply to keep around.

InTheMail | Voltlog #413

Welcome to a new InTheMail, the most popular segment hosted here on the channel and for today I have lots of really cool gadgets to show so stick around for that.

I’m gonna start the video with this Xiaomi / Honeywell Smoke fire alarm sensor. Obviously Honeywell is a very well established brand when it comes to sensors so Xiaomi partnering with them totally makes sense. There are a bunch of different variants for this sensor available on the market. This one in particular is model number GD-03MI/BB and this is a bluetooth sensor. I wanted a zigbee sensor but I couldn’t find it in stock with Banggood so I had to go for this bluetooth one, it shouldn’t be a major issue as I have bluetooth connection on my homeassistant server as well. That’s the plan to connect this via Bluetooth to homeassistant so that I get smoke alarm capability via HomeAssistant. 

You could also use this with a Xiaomi gateway and get the notifications in the Xiaomi app but I prefer to use HomeAssistant and this device seems to be supported by the Passive BLE integration which should automatically discover it. This sensor uses a CR17450 lithium battery which is not that common and they tend to be more expensive because of that, luckily it does come with an included battery which should last up to 5 years according to the datasheet. I would be happy even if it lasted just 2 years and would consider anything above a bonus.

I have yet to test this, I will be running some tests after installing it but I can tell you that it also provides local light and sound alarm so you don’t need to rely on having it connected, it will sound it’s 80dB buzzer when smoke is detected and just considering that it uses Honeywell sensing technology with the higher quality of Xiaomi products, this has to be more reliable than the no name brands that you can find online so if you are interested in getting one, there will be a link provided in the description below.

InTheMail | Voltlog #410

Welcome to a new InTheMail the most popular segment hosted here on the channel and I’m gonna start the video with these two products, these are ESP32-S2 based TFT display modules. They’ve been sent in from makerfabs. They have two options when ordering these, you can go with a resistive touch interface or a capacitive one and I guess you would want the capacitive type unless you have a specific application where it would be difficult to go with the better and more sensitive capacitive touch like, I don’t know you want it to operate with gloves maybe?

The screen resolution is 320×480 pixels, not super high pixel density but decent for most projects and because of the ESP32-S2 which drives these panels over a parallel interface you can get some high throughput and makerfabs claims it’s even possible to play video on these. To give you a sense of that, I’ve loaded some of the provided examples based on the LGFX graphics library and it’s clearly visible that we’re getting some pretty high refresh rate on these.

And since we have that powerful ESP32-S2 with Wifi connection it’s easy to think of various projects where might make use of these. For example I could see this being used as a wall thermostat interface for HomeAssistant, it could be having some touch buttons for setting the temperature but it would also function as an always on display showing you some sensor data grabbed over MQTT from the HomeAssistant server.


So this is a really nice package for those looking to integrate a TFT display into their next project, it has everything you could need, some spare IO, native USB connection from the ESP32-S2 and a second usb to serial connection, speaker output, micro sd card slot, the schematic and board files are provided on github so really all you would have to do is to write some firmware and maybe 3D print an enclosure to protect it.

InTheMail | Voltlog #408

Let’s start with this raspberry pi 4 aluminium heatsink/enclosure, I prefer these over a traditional plastic enclosure and over traditional metal enclosures because these can also act as a passive heatsink. Going with just a plastic enclosure isn’t gonna work for you unless you plan to keep the raspberry pi idle all the time and going with a metal enclosure would also require installing some heatsinks and or cooling fans. Depending on what you are running on the pi you might get away with just passive cooling from one of these.

This one apparently is designed specifically for the pi4 so the aluminium islands that are supposed to contact the chips have exactly the right shape and size for that. It’s important to search for one advertised for the model of pi you have to get that perfect fit and optimal cooling. This one is for my homeassistant server, I will likely install it on a DIN rail so I will probably use some zip ties in the beginning and then depending if I ever feel motivated enough and have the time I will also design and 3d print some kind of DIN rail mount for this enclosure. Same as always links for all of the products shown in this video will be placed in the description below so do check them out. Oh and I know raspberry pi boards are hard to find these days, if you are in the EU, last time I ordered mine from WELECTRON.COM checkout their website to see if they still have any in stock.

InTheMail | Voltlog #403

Let’s start with this product from SONOFF, this is a USB zigbee adapter which is useful if you want to add zigbee connectivity via USB, for example I plan to use this with my RaspberryPi running HomeAssistant to be able to connect to a bunch of zigbee sensors I have around the house.

Zigbee for me is very convenient because it’s very low power and thus can make replacing batteries on my sensors a thing I only have to worry about every few years but depending on which zigbee gateway you are running things can run smooth or you can have hiccups like it was my case with the sonoff zigbee to wifi bridge which I used in bridge mode so far. I am having a bunch of connection issues so I decided to upgrade the zigbee dongle, this new one, also from SONOFF is based on TI CC2652P which is well supported by the zigbee2mqtt framework and supposably can support a higher throughput while being more stable.

I believe I will need to open this up and flash it with a different firmware but that’a a subject for a different video, bottom line is that right now this is the most affordable good zigbee adapter that you can get and if you want one, I will place a link to this in the description below.

InTheMail | Voltlog #398

Welcome to a new Voltog, Happy New Year and what other better video to start the year with, than a genuine InTheMail to feed that need for new and interesting electronics. Just a quick heads-up, I’ve left the most interesting item in today’s mailbag to be presented last but trust me it’s worth watching till the end if you like to keep your electronics workbench clean.

Let’s start with this set of replacement foam pads for these Sennheiser headphones. I’ve had these for a long time, never used them that much but as with all headphone cushions, they started to disintegrate after a few years and I feel bad letting these go into the trash, knowing that they are perfectly good headphones. So I decided to buy a replacement foam pad set to repair them and maybe give them to someone that needs a pair of headphones so that we’ll get maybe at least another couple of years out of this good product. That’s how I generally feel about products that have served me well, they don’t deserve to end up in a landfill, how do you feel about that? Let me know in the comments below and if you find yourself needing some replacement foam pads for your headphones, check out the links I’ve placed in the description of this video to find some for your particular model.

Next up I have some tactile switches, these are just generic ones that I got from aliexpress, they are right angle through hole mounting style and I’m using these on my esp32 thermostat valve controller board and this is a suggestion that I got from a viewer in the comments, because it makes the switch easily accessible through the openings in the din rail enclosure. These are likely a clone of the SKHH series from ALPS because I used the footprints for those, found in the standard Kicad library and they match. Even though I got them for cheap, they seem to be of decent build quality but getting them from aliexpress is always a gamble because on the next batch they might not be the same so I’ll be using these for my prototypes but I’m looking for alternatives from a known supplier to eliminate any quality issues.