Day: December 8, 2022

Singapore Branches Out Into Internet Of Trees

December 8, 2022 by 18 Comments

Five years ago, a 38-year-old woman was enjoying an outdoor concert with her family with one of her twin infants in her arms. In the week prior, it had been windy and rainy, but today, the weather was nice, and the concert was crowded. Without warning, a 270-year-old tembusu tree fell on the woman, pinning and ultimately killing her after the other concertgoers couldn’t remove it in time. This tragedy happened in spite of twice-yearly inspections where the tree showed no visual signs of trouble.

It’s exactly this type of incident that Singaporean officials hope to avoid by building an Internet of Trees. The equatorial island nation is home to roughly 5.5 million people, and around 7 million trees — about 6 million of which are tracked by Singapore’s National Parks Board, so that they can be managed remotely with an app. (The Board only tracks trees once they’ve reached a certain size, so we’ll assume that the other million are too young to join the fun just yet.)

While tree-triggered deaths are fairly few and far between, there are plenty of other ‘tree incidents’ that can occur, such as a branch falling, or a tree trunk snapping or uprooting. Depending on the size of the branch, this can be a dangerous nuisance as it could block roads, obscure signage, or destroy property. Thanks to the efforts of the National Parks Board, these incidents have dropped from around 3,000 per year at the turn of the millennium to under 500 per year today.

Continue reading “Singapore Branches Out Into Internet Of Trees” →

Audio Amp Puts VFDs To Work In An Unusual Way

December 8, 2022 by 14 Comments

It’s safe to say that most projects that feature a VFD emphasize the “D” aspect more than anything. Vacuum fluorescent displays are solid performers, after all, with their cool blue-green glow that’s just the right look for lots of retro and not-so-retro builds. But that doesn’t mean there aren’t applications that leverage the “V” aspect, such as this nifty audio preamp using VFDs as active components.

The inspiration behind [JGJMatt]’s build came from the Korg Nutube line of VFD-based low-voltage dual-triode vacuum tubes. Finding these particular components a little on the expensive side, [JGJMatt] turned to the old standby DM160 VFD indicator tube, which is basically just a triode, to see how it would fare as an amp. The circuit takes advantage of the low current and voltage requirements of the VFDs — the whole thing runs from a USB boost converter — by wedging them between a 2N3904 input stage and a 2N2007 MOSFET output. There’s a mix of SMD and through-hole components on the custom-etched PCB, with a separate riser card to show off the VFDs a little bit through the front panel of the 3D printed case.

All in all, we find this little amp pretty cool, and we love the way it puts a twist on the venerable VFD. We’ve seen similar VFD amps before, but this one’s fit and finish really pays off.

An Affordable And Programmable PLC

December 8, 2022 by 72 Comments

We’re all used to general purpose microcontroller boards such as the Arduino or its many imitators, but perhaps we don’t see as much of their industrial cousins. A programmable logic controller (PLC) is a computer designed to automate industrial machinery, and comes with protected interfaces and usually a specific PLC programming environment. Thus [Galopago]’s work with an inexpensive Chinese PLC clone is especially interesting, providing a route forward to using it within the Arduino IDE ecosystem.

Opening it up, the processor is identified as an STM32F103, and the connection needed to place it in bootloader mode is identified. Then it can be programmed from the Arduino IDE, even though its bootloader can’t be changed. Then to complete the process it’s necessary to identify the various different inputs and outputs by old-fashioned hardware reverse engineering.

This PLC may not be quite as robust as some products costing much more money, but it still represents a cost-effective way to access a microcontroller board with much of the interface circuitry already installed that would normally be required for controlling machinery. We expect that we’ll be seeing it appear on these pages over the coming months, and perhaps there might even be another comparison in the air.