Category: InTheMail

This category will hold InTheMail articles.

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.

InTheMail | Voltlog #393

Let’s start the mailbag with this tiny PIR motion sensor switch. This little guy is rated for 12V up to 2A load so it’s got an input, you supply 12V to that and it acts like a switch for the output with a 2A load capability. It comes with these connectors witches makes me think it’s meant to be used as part of led installations, maybe for custom furniture or cabinets because it has this mounting bracket and that’s probably how I am going to use it, to light-up this warm white LED tape that I have built into a piece of furniture. This is rated for indoor use only so don’t go using this outdoors as water will get in and corrode the electronics inside. Same as usual links for all of the items shown in this video will be placed in the description below and while you are down there, why not smash that like button, because it really helps increase the chances of this video being seen by more people, it’s just how the algorithm works.

Next up I got some transparent heatshrink, I needed some of this recently so I got two different thicknesses, Sometimes you just want to be able to see through the heatshrink part or you might just want to insulate some metal rod without adding any color so the easiest way to do that is to use some transparent heatshrink.

10 Gift Ideas For Electrical Engineers In 2021 | Voltlog #389

If you are an electrical or electronics engineer then you probably noticed how non-technical people around you are struggling when it comes to choosing a gift for you and if you are a non-technical person and you need to buy a gift for an engineer, then this video is for you so stick around.

Unlike other similar videos which will generally recommend gift ideas without actually testing them, I’m  going to recommend stuff that I personally own and have used for enough time to know if it’s any good or not. For all of the stuff shown in this video there will be links in the description to Banggood, Amazon or Aliexpress which are the usual places where I do my shopping and I decided to release this video a little early because there is the 11.11 shopping festival on Aliexpress and Banggood and you might get some nice discounts on these orders.

InTheMail | Voltlog #386

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. Checkout the items I received in this mailbag which include: raspberry pi CM4 heatsink, Mains powered PIR sensor, Parachute cord mini carabiner, Nylon tactical mini hook, DIN rail enclosure, transparent din rail enclosure, Dremel tool key, Drilling dust collector, OV2640 camera for esp32-cam, Molybdenum diamond wire, 50ohm in-line BNCload.

InTheMail | Voltlog #382

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. Here is an example of how I am getting most of my packages lately, they’re bundled like this and forwarded through the EU so they take a different route and don’t go through the normal customs import and taxation protocol and I’m fine with that because VAT has been paid at the sale point anyway there is no reason to pay any additional handling fee.

Let’s start with piercer probes and if you remember I have shown something similar in the past but they were  simple piercing needle probes, I have used those, they work both for piercing wiring for probing and also for inserting into female thin profile connectors. Now I got these which are a variation because they contain the same very sharp needle but I think these are nicer because they can also hold the wire you are probing and there is less of a risk of stabbing yourself in the finger as it was the case with the simple ones. On the back they have the same standard 4mm banana insert so you can hook these up with your standard 4mm test leads. I quite like them so they will be a nice addition to my box of probing accessories which is this one 

InTheMail | Voltlog #378

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. I have some news regarding the import of our packages from Aliexpress into the EU. It seems our Chinese friends re-grouped and found a way to improve things for us. So half of my packages are still coming  through as normal with quote marks, because I’m there is a double taxation happening, the electronic system is not operational here yet so they charge VAT a second time when you receive the package plus a 2 EUR handling fee but the other half o the packages started arriving grouped into larger bags through EU routes without having to go through customs. I think that’s a plus because it avoids the double taxation that was happening here plus I get more packages at once, less hassle. I’ll keep you updated in future videos on the status of these packages.