Welcome to a new Voltlog, you might remember these two sensors from a previous mailbag, this is the MH-Z19B and this is the CCS811 both of these report CO2 levels but they measure this differently and I’ll explain this in a moment. I got these two sensors in order to monitor CO2 levels in my home, to determine if the levels rise too much at night, especially during the winter time when we tend to keep the windows closed most of the time. I live in an old apartment building where there isn’t much provision for ventilation and so I suspect the air I breath during sleep is high in CO2 levels as it builds up over night.
In this video I’m gonna show you how I built the monitoring system using an ESP32 board that reads the sensor data and then sends it over the network to an MQTT server running on my raspberry pi. I then use node-red to insert the data into InfluxDB and then finally Grafana to monitor all of this data in a nice graphical user interface. The beauty of this setup is that all of this software is free to use and open-source.
Welcome to a new Voltlog, today I’m gonna show you how to setup your own GPS tracking server on a raspberry pi. It doesn’t have to be a Raspberry pi, because the software that we’re going to be using for the tracking server is available for Windows and Linux as well, so you could host this on your windows machine or in a virtual machine on a cloud service, it’s up to you, but in this video I’m going to do it on a Raspberry pi 4.
The idea started a couple of videos back, in Voltlog #272 when I got this GPS tracker disguised into a general purpose automotive relay. In theory this should come with free online tracking service on some Chinese hosted server but I wasn’t able to connect to that server and so I thought why not setup my own server and try to pair it with this tracker. So if you want to learn more about this tracker, checkout Voltlog #272 linked on screen right now and then come back to watch this video.
First step is to setup a fresh install of Raspbian, latest version from the source. Next step is to setup the tracking server, the name of the software is Traccar and here is their website. We’re going to be using the Linux arm release, because the raspberry pi runs on an arm processor. Next, your raspberry pi is likely sitting behind a router or firewall so you will need to forward a port so an external device like a GPS tracker can connect to our newly created server.
Next we can add our GPS tracker in the web interface of Traccar, on the left side I click add, choose a name for your device and fill in the 10 digit identifier which is this label on the side of your trackers case.The newly created device will be shown as offline until the server starts receiving data.
The final step is to configure the GPS tracker and these particular commands apply to the tracker that I am using, you might have to use different commands for a different tracker but the idea is to reset the tracker, set your admin number, configure the APN settings for your network operator, set the external ip address we saved earlier, the port is 5013. Set the upload frequency in seconds and enable the GPRS connection. Going back to the Traccar web interface, status should switch to online and we should start seeing data about our device.
Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. Before I get started I’m gonna take a second to reminding you to subscribe to the channel and hit the bell notification icon because that’s the only way you will know for sure when I upload new videos. Now let’s start with this small esp32 based development board, it has a built-in 1.14 inch color tft lcd and I think that’s a nice feature of this dev board because if you want to connect some sensors and see the readings in real time, you don’t need to wire a display externally it’s built-in.
Another cool feature is that we have built-in battery charging at 500mA and you can power this board through the provided two pin jst connector with a one cell lipo battery which will then charge when connected to power via the USB Type-C port. There is also a CP2104 for the usb to serial conversion and that makes it a pretty well balanced development board for the ESP32.
The board comes loaded with a test program from TTGO, it shows this image then cycles through red, green, blue on the LCD which is a good idea because you can verify the board is functioning ok after the long journey it takes from the market in shenzhen to your door and we all know how well these packages are protected during shipping.
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.
Welcome to a new Voltlog, this will be just a short video, I want to talk about the prices and the discounts that we get on shopping festivals, because most of us think and myself included here, we think the price cuts we get for these shopping festivals are not actually true, we tend to think prices are inflated some time ahead only to be discounted on that day which makes them go back to roughly the same price they normally sell for.
Even in my past video with shopping suggestions Voltlog #269, I got such comments and I don’t blame people for thinking this, because like I said, I tend to think the same but I also want to find out the truth so what I did some time ago, beginning of September to be more precise, I save some screenshots of various items that I was interested in from A
liexpress.
Today it’s the 11th, the sale started so we’ll compare prices before and after, to see if the sellers actually raised their prices before the sale and are we really getting any discounts today.
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.
Welcome to a new Voltlog, today we’re going to take a closer look at an ultrasonic cleaner. This is the 1.3 litre, model number I believe is Y-009, the ultrasonic power is 60W while the heating power is rated for 100W. Usable area I’ve measured to be 125x115x40mm depth which is not a lot but I’ve thought about it and this is pretty much all I need. 99% of the PCBs I design fit within these dimensions so it’s not worth getting a bigger ultrasonic cleaner because it will take up more space and it will use up more cleaning liquid, it would be a waste of resources.
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.
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.
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.