Update July 2025. From the comments I see many people having problems replicating what I did. I strongly suspect compatibility issues with the latest Arduino software / IDE. I originally did this work in 2022 so there will have been…
Siglent SSA3021X Spectrum Analyzer Web Interface
I have a Siglent SSA3021X spectrum analyzer. I like it a lot, and it’s been used for some other posts here. For example looking at LORA signals. I’ve long wished it had a web interface for screen captures. So I…
Viewing LoRa Spread Spectrum on a Spectrum Analyzer
I’ve been doing an interesting project, writing some LoRa code in Python on an ESP32. There are lots of resources on the web, including other example codebases in github etc, which means I didn’t have to start from scratch. Fairly…
MQTT Test Topic
This is a test of the DIOT MQTT plugin. Although it looks rather boring, I’ll leave this post up because it’s useful for testing. [diot topic=”frankvh_test/test_topic”] [diot topic=”ecava/igx/temp”] Some data should appear. If you see any numbers changing, then…
Fun With MQTT, using ESP8266, Arduino and Android
MQTT is a simple protocol for sharing small packets of data with multiple devices. Although it’s been around since 1999, the last few years it’s been growing in popularity as part of the whole “internet of things” movement. I decided…
FreeNAS upgrade – Making Rsync Backups Work Again
Recently I upgraded to FreeNAS 9.10. Not that there was anything inherently wrong with my previous 9.2 system, however it was booting from a USB stick, which died (my second USB stick to die over the past few years), so…
SSD1289 Landscape Mode & TFT Screen Rotation
A lot of the SSD1289 based TFT displays commonly available ship by default in portrait mode. Which is to say, 240 pixels across by 320 pixels deep. When you read the SSD1289 datasheet it would appear the chip defaults to…
Turn off XML-RPC on WordPress
This site is running WordPress, which is a double-edged sword. On the positive side, it’s a stable easy-to-use system with lots of options, themes, customizations, etc. On the negative side, it’s very popular hence WordPress sites are a popular target…
Cloudflare For The Win
Although this is a fairly low-traffic website, it still gets visitors from all over the world. I use low-cost web hosting based in North America, which historically means my international friends tend to see slow performance when accessing the site.…
Fast RGB332 to RGB565 Colorspace Conversion
I’ve recently been working on a project with a small 320×240 TFT display connected to a microcontroller. In this case an ARM Cortex-M0+. Being able to display images is a really nice feature, however images can consume a lot of…