Author: voltlog

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.

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.

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.

Best Affordable USB Analyzer QC/PD AVHzY CT-3 Shizuku | Voltlog #407

Welcome to a new Voltlog, In this video I’m gonna show you what I think it’s the best affordable USB Meter you can get right now in terms of functionality and build quality. The functionality built into this usb meter goes beyond your imagination and it’s hard to even remember all of the different functions this meter will support and the PC app they offer has to be one of the best apps I’ve seen from a Chinese company. It doesn’t mean it’s perfect, might still have a few bugs but definitely the best choice you can make right now.

The meter is branded AVHzY, the model number is CT-3 and full disclosure here, they offered this unit for free for the purpose of this review but they don’t pay me and I have full control over this review. The meter comes in a hard shell case so it’s well protected during shipping and to my surprise I got this in just under 2 weeks while the usual transit times for my packages are in the 3-4 weeks. Inside you get this english quick start guide, there was also a screen protector film which I already installed, it went in there perfectly and I really appreciate having that included because it was the perfect size.

This is the typical USB meter sandwich construction with different layers, this one seems to be using a single PCB in the middle with a couple of metal sheets on the outer layers which makes it feel premium and more rugged than simple plastic. We have the typical USB Type-A connectors for input and output , USB Type C input and output and also a micro USB for PC connection. The LCD is 128*160 pixels at just 1.77” which is not a lot, you can definitely see those pixels but for a small USB Meter I can’t complain, it’s still readable.

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.

VoltLink revC CP2102N USB Serial Bridge & ESP32 Programmer | Voltlog #405

Welcome to a new Voltlog, a rather short video for today. I’m gonna be showing you the latest revision of the VoltLink USB To Serial Adapter. This is revision C and while this revision doesn’t necessarily bring any new functionality to the VoltLink it does optimize the design for manufacturing a little more which makes it easier for me to build these units.

Before I go into more details let me just quickly mention that if you would like to order one of these, they are available on Tindie and there will be links in the video description to the product page.

So like I mentioned, no new functionality added in revC, but that’s okay because I’m pretty happy with the functionality we have so far, I mean there is USB Type-C which means you no longer need to resort to the older micro usb cables, you got over current protection at 500mA, ESD protection.

We still have a high quality, high speed, usb to serial converter in the form of the CP2102N which enables baud rates up to 3M baud and this significantly improves the time you need to flash your board and you will quickly get used to this higher speed so much that when you switch to some other converter or board that only supports lower baud rate you will feel how slow that is.

We still have the 500mA rated low dropout regulator which provides 3.3V to the target board and 500mA is enough to cover the majority of boards that you will be programming. For example all of the ESP32 based boards that I design can be powered by the VoltLink while flashing firmware with no issues. Additionally I showed in a recent video that with a custom optional cable that you can order with the VoltLink you can safely flash Shelly relays without having them connected to mains voltage.

How To Flash Shelly Relays With Tasmota Or ESPHome | Voltlog #404

Welcome to a new Voltlog, in this video I’m going to show how to flash your Shelly relay with Tasmota or ESPHome, the easy way, using the VoltLink USB to serial converter. What is a Shelly relay you might ask? Well, if you are into home automation, a shelly relay is a wifi connected smart relay, built into a very compact form factor in order to fit inside electrical junction boxes like behind wall switches or wall sockets.

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.

Owon SPE6102 Power Supply Review & Teardown (SPE Series) | Voltlog 400

Owon have had a bunch of power supply models in their lineup for a while but this new addition, the SPE series caught my eye because it’s in the affordable budget range and I really wanted to give this one a try to see if any good and if it will earn it’s spot on my workbench. So join me in this video to learn more about it.

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.