Who’s following me on Twitter probably knows some details. I believe this is my most expected article. Last year I came up with the idea to build a wideband SDR. It’s fun to monitor a wider spectrum and some signals. Sure, USRP is cool but too expensive for amateur usage. I had a few HackRF boards, so I ordered more…
Housing for the 1PPS/Square clock 8 channel distribution amplifier
While experimenting with my clock distribution amplifier, I found that this board creates a lot of interference to my HackRF receivers. Plus, it’s not very convenient to work with a bare board. I decided to build metal housing for this board. This is just a little note about its construction and some nuances.
Tesla Model 3 US – LTE modem replacement (And some reverse engineering)
Recently I bought a used Tesla Model 3 delivered from the US. It was an excellent deal. The car is in great shape and condition. Since I’m in Europe, there are few nuances with this car. One of them is an American LTE modem. American and European LTE frequencies are slightly different; that’s why the original modem is not working…
1PPS/Square clock 8 channel distribution amplifier
This is a “production” version of my 1PPS distribution prototype. Now, this device supports 1PPS and Square clock signal distribution for 8 consumers. The new device is designed with lower delays and flexible configuration in mind. You can find the schematic and all required production files below.
1PPS distribution circuit
1PPS is a great way to synchronize multiple devices and measure time intervals. A typical source of the 1PPS is a GPS receiver. This clock is disciplined by GPS atomic clock and has a reasonable precision. GPS receiver 1PPS output should have enough loading capability, but it’s a good idea to use a buffer. Especially when voltage level translation is…
Hacking Bluetooth speaker/FM radio firmware
I have a little Bluetooth speaker/FM radio. This speaker is not perfect, but it is nice for its price. Except for a few annoying things regarding sound notifications. I decided to “fix” those issues. A little bit of reverse engineering was involved.
Small satellite dish with rotator
Receiving and analyzing radio signals is fun. Receiving satellite signal is even better. A few years ago, I had a nice 3m satellite dish with a hydrogen line receiver. Now I have only a small balcony with limited antennas placement ability. I decided to build a custom 40 cm dish with a servo-based rotator. Sure, it’s impossible to receive weak…
Compact and powerful DC driver using IRS2104
A few years ago, I wrote about the powerful DC motor driver based on IR2110. This construction appeared to be quite popular. This time I want to describe a much compact and simpler (but still very powerful) solution with IRS2104. This device can be used to control any power-hungry DC load like DC motors, heaters, and so on.
Writing a PCI device driver for Linux
In this article, I want to discuss some basics of the Linux PCI/PCIe drivers development. I think this issue is not properly covered, and some existing information is might be outdated. I will show basic concepts and important structures, and this is might be a good beginner guide for newbie driver developers.
Satellite LNB controller with GUI interface
Satellite LNB are quite cheap and easy to get devices. There are different models for different bands (C, Ku, and Ka) with different characteristics like SNR, noise figure, etc. Typically those devices are used with TV Set-top boxes. More interesting is that LNB can be easily connected to an SDR receiver. LNB is a simple frequency down-converter with an output…