gerryk.com

Wherein I write about things that interest me….

Getting data from CurrentCost to HomeAssistant with rtl_433 and MQTT

I have had a CurrentCost Power sampling device on my house electrical supply for a few years, since I got it free switching providers. It came with a panel that allows you to view the momentary values for power consumption, but in these days of data aggregation and IoT, this is as close to useless as it gets. I already have a HomeAssistant server runniing on a Docker Host I use for such things, and I have a few other IoT-friendly devices lying around, so I thought I would try to integrate these to gather and display historical power consumption for my home. Read more →

Flashing the Arduino Bootloader to a Bluepill STM Board

Recently I have been seeing the ‘Bluepill’ STMicro based development board popping up more and more in projects. The Download Arduino IDE Download STM_32 Utils Copy to ~/Arduinno/hardware or ~/Documents/Arduino/hardware (Win + OSX) Add SAM boards via board mgr. Download st-link urils Download bootloader firmware (I used default, LED13) Connect as follows: Flash using this command… .\st-flash write ..\generic_boot20_pc13.bin 0x8000000 Read more →

Using Ghidra to Reverse Engineer Wifi Pineapple Protection

I prefer to build my own hack-tools. Partly because I am a cheapskate and partly because it is more educational. One device I have often thought of replicating but until recently hadn’t gotten round to it is the Wifi Pineapple from Hak5. This is basically a productified Wifi Attack Platform / Rogue Access Point. In past blog posts I had read that it is based on OpenWRT, and that the hardware is almost identical to the much cheaper GL-Inet AR-150 Wifi Router. Read more →

Moving to a Static Site Generator

I had been considering moving away from the CMS model of hosting for my blog to a static site generator for some time, when the Drupalgeddon issue hit in 2018. I was not in a position to migrate at the time due to a fairly invasive bout of eye surgery, so took the site down until such time as I was. During the intervening time, I did some research and among the shortlist was my eventual choice, Hugo. Read more →

Building MCHF: A next-generation QRP SDR kit

A while ago, while browsing Ham Radio channels on Youtube, I came across an interesting project. Chris, M0NKA, an obviously talented hardware designer had designed a QRP Software Defined Radio (SDR) based on the STM32F407 from STMicroelectronics. The STM32F407 is a System On a Chip (SoC) that includes a Cortex M4 CPU core running at 200MHz, and some high-speed DAC/ADCs, capable of up to 7Msamples/sec, so a good candidate for a single-stage superhet Software based radio. Read more →

Bitcoin full-node on Raspberry Pi with NFS storage

I recently augmented my home-server with a bunch of additional storage. Since I have all this space, and a few Raspberry Pis lying around gathering dust, I though I might try running a Bitcoin Full Node at home. This has a couple of positive effects… it strengthens the overall bitcoin network, and it gives me a trusted verification for any inbound transactions. I first created an NFS share on my home server… I allocated a 250GB LVM volume with an EXT4 filesystem to it, added it to /etc/exports and restarted nfs service. Read more →

Bittrex.com Unicode URL phishing scam

68,I occasionally use Bittrex to trade cryptos and were it not for my password manager, I would probably have fallen victim to a pretty subtle phishing scam.. The scam relies on the fact that in the huge unicode character set, there are many glyphs that look very like standard the roman characters we are used to as far as URLs are concerned. Many browsers do not make any visual distinction either, so if a letter looks like an ‘A’ for example, only some digging will reveal that it is in fact another character entirely. Read more →

Building KV4QB’s S9 Signal Generator

65,I have previously talked about the highly informative blog run by DuWayne Schmidlkofer KV4QB. He often publishes board designs which he is happy for people do reproduce using their PCB house of choice. In the past I have built his Scalar Network Analyser, which has proved to be invaluable when tuning filters and building antennas. He has another project that I thought would be a very useful tool to have for any radio amateur interested in building their own rigs. Read more →

SBC6120 - RetroBrew Computers Edition

63,Following on from here. Farnell were typically swift with their turnaround wit most of the components arriving within a couple of days. I was not so timely, in either building out the board or writing it up, but better late than never… I had also ordered a CF to IDE interface. There is an IDE interface on the SBC board, but these days, it’s hard to find an IDE drive, and who wants a spinning platter with all of its attendant power consumption issues when a little bit of flash memory would do just as;well. Read more →

DIY Wonder Loop QRP Antenna

61,I am a member of a group on Facebook that shares and discusses antenna designs, usually of a portable nature. Recently the topic of the WonderWand WonderLoop antenna came up, particularly how expensive it is relative to its apparent complexity. A number of members had posted pictures of a torn-down control box, and it really seemed to contain little more than a transformer wound on a mix-6 toroid and a variable capacitor. Read more →