review – Page 2

Voltlog #282 – Did I get a trinocular microscope for micro-soldering and inspection?

Welcome to a new Voltlog, to save you from waiting, the short answer is yes, I did get a microscope for the lab but before I show you the microscope let’s talk about why I got a microscope and why you might want one. If you are occasionally soldering boards, electronic kits, mostly through hole components or even surface mount down to 0603 and you have good eyesight, then chances are, you don’t need such a microscope, I’ve been doing that for years.

On the other hand, if you want to be able to solder surface mount components smaller than 0603 comfortably or you want to do board level repairs on modern gadgets like smartphones and laptops, then you most definitely need a microscope as it will massively improve the quality of your soldering and the general repair process at your bench.

Voltlog #280 – TPS62840 olmBoard Ultra Low Power Step Down Converter

Welcome to a new Voltlog, in this video we are taking a look at the TPS62840 ultra low power step down converter from Texas Instruments. It’s basically a buck converter with an input voltage of 1.8-6.5V, 750mA output current, with a quiescent current of just 60nA and active current of just 120nA. It also features very good efficiency at light loads of just 1uA it can offer 80 percent efficiency.

Other features include 16 selectable output voltages through an external resistor and a stop pin which when activated will completely stop any switching to eliminate any switching noise for a short moment, allowing you to take for example an ultra low noise measurement during that time. During that take power will be sourced from the output capacitors. So it looks like this is a pretty interesting dc-dc converter, with really nice features and it’s optimized for ultra low power devices.

Voltlog #272 – Car Relay GPS Tracker Setup CJ720

In this video we’ll take a look at the CJ720 car relay gps tracker, I’ll show you how to setup the tracker and how to get position information. I will show you what kind of commands this tracker accepts and I will also do a teardown towards the end.

For information on how to setup your own GPS Tracking server, running on a raspberry pi, using open source software, checkout Voltlog #274.

Voltlog #269 – 11.11 Shopping Suggestions For Makers

Welcome to a new Voltlog, it’s November and that means the biggest shopping event happening in Asia is coming up, I’m talking about the 11th of november. There are some numbers published for last years event and it seems they registered more than 30 billion in 24 hours in sales, yes you heard right, billions. So it’s a very big event with nice discounts and opportunities for makers like us to get some new gear. That’s why I prepared this video which will be published 1-2 days before the event so you can get some ideas of stuff that you could purchase. I assembled a list, these are products that I’ve tested and used myself which I think are good value for money and a nice addition to any hobbyist lab.

Voltlog #268 – RaspberryPi 10 Inch IPS HDMI Monitor 2560×1600 2K

Welcome to a new Voltlog, it’s product review time again, this time we’re taking a closer look at a 10 inch monitor with hdmi input. This is the box it comes in, the monitor has a resolution of 2560×1600, that’s about 2K resolution in the scheme of things, 300 pixels per inch density, 16:10 aspect ratio which I’m a fan of. My desktop monitor is also 16:10 and it works so much better for everyday activities but especially if you are doing any CAD design work. It’s an IPS panel so we should have good brightness, contrast and colors, it’s rated at 400 candela per sq meter. We also get built-in speakers and the HDMI supports video & audio so you should be able to get video and sound through the HDMI cable and that’s useful because we have built-in speakers on the monitor itself.

Voltlog #266 – How To Check If Your Raspberry Pi 4 Is Throttling CPU

Welcome to a new Voltlog, today my raspberry pi 4 is again in the spotlight because I want to show you the different scenarios where the board could be throttling down the CPU frequency and how you can identify those. Because it might be a case where your raspberry pi is running slow on a particular task and you don’t know why because there is no built-in mechanism to let you know when the board is throttling down. There are logs which you can check but let’s be honest, few people actually check the logs for something like this.

Throttling of the cpu frequency occurs for good reasons, to protect the board or the cpu from overheating or to prevent any errors from occurring in the case of an under-voltage scenario which may lead to data loss or corruption. Luckily there is a way to check if your system is under one of these conditions, you can run this command on your raspberry pi.

Voltlog #265 – FT232H USB to JTAG/I2C/SPI Interface With Python & PyFtdi

Welcome to a new voltlog, today we’re going to be talking about this little board which I designed and assembled myself, it’s a breakout module for the FTDI FT232H which is a usb to serial converter but with a nice twist. This particular chip from FTDI has the built-in Multi-Protocol Synchronous Serial Engine (MPSSE short) which allows you to run a variety of synchronous serial protocols like JTAG, I2C, SPI or simple bit-banging of IOs. You can imagine it can be really useful to be able to interface with a sensor over I2C or SPI straight from your computer over USB through this interface. You wouldn’t need an arduino or other controller in the middle if you plan to do some data acquisition for example.

Voltlog #264 – Passive Heatsink Cooling For The Raspberry Pi 4

Welcome to a new Voltlog, here is my raspberry pi 4 which I got a few months ago when they released it and if you have one you might have noticed it gets quite hot especially when it has to do some processing. This newer processor, will get hot quick and the board alone cannot cope with all of this heat so what does it do? Well when the CPU temperature reaches 80 degrees Celsius it will start throttling down the CPU as a way of protecting itself from overheating and this will result in a loss of performance.

The Raspberry Pi 4 has a 1.5GHz quad-core 64-bit Arm Cortex-A72 CPU, that’s roughly three times the performance of the raspberry pi 3 cpu. That inevitably generates more heat. In the original plastic case just sitting idle, connected to a network, doing pretty much nothing, the raspberry pi4 when compared to a raspberry pi3 runs about 12 degrees hotter.

Voltlog #262 – Is This The Future of Our Hobby?

To be honest I didn’t think we were going to have services like these available so cheap so fast. I mean yes I know pcb prices have been so low in the past couple of years that it no longer makes sense to etch your own PCBs, unless you are in a big hurry. But having smt assembly service so cheap? Soon enough it would not make sense to hand assemble these boards because it would be equally cheap to have them assembled at JLCPCB

Voltlog #260 – How do you test usb to serial converters? (CP2103 vs CH340E vs FT232RL)

Welcome to a new Voltlog, today we’re comparing a few different serial to usb adapters and the discussion started ever since I showed the CH340E breakout board I designed in voltlog #249. People wanted to know if this CH340E affordable chip would perform similar to the well known FTDI or Silicon labs chips, and I’m thinking at high throughput and reliability here, the kind of application where you are sending lots of data, fast and you need it to be transferred reliably.

So today I’m going to compare the CH340E with a CP2103, and the FT232RL. I wasn’t sure what measurements to take and how to test these but I devised 2 testing methods.