Tony Cox
@thesoupdragon.bsky.social
CEO, UK Biocentre, Milton Keynes. @ukbiocentre.bsky.social
Vintage HP test equipment enthusiast. Electronics tinkerer and fixer-upper. Opinions are my own.
Vintage HP test equipment enthusiast. Electronics tinkerer and fixer-upper. Opinions are my own.
You have to admire the tenacity of this old ash tree.
September 28, 2025 at 12:06 PM
You have to admire the tenacity of this old ash tree.
More or less complete. Added auto-cal and (after a couple of dead ends) I got Tx back-off working using LoRa’s channel activity detector (CAD) system. Packet Tx will delay up to a limit and if still stuck they are dropped. Reduces collisions dramatically when traffic is high.
August 16, 2025 at 7:06 PM
More or less complete. Added auto-cal and (after a couple of dead ends) I got Tx back-off working using LoRa’s channel activity detector (CAD) system. Packet Tx will delay up to a limit and if still stuck they are dropped. Reduces collisions dramatically when traffic is high.
After several weeks of learning about LoRa networks my sensor network is finally running. Custom sensors based on a RAK3172 broadcast to a Heltec LoRaV3 receiver which filters and aggregates data. This sends the data via a high speed (wired) UART to a NodeMCU. This bridges data to WiFi and MQTT.
August 3, 2025 at 7:53 PM
After several weeks of learning about LoRa networks my sensor network is finally running. Custom sensors based on a RAK3172 broadcast to a Heltec LoRaV3 receiver which filters and aggregates data. This sends the data via a high speed (wired) UART to a NodeMCU. This bridges data to WiFi and MQTT.
Floral theft! This bee is far too big to crawl into the Hosta flower - so it heads up to the neck of the flower, cuts a neat hole and “steals” the nectar. Crafty 🐝
July 16, 2025 at 6:12 PM
Floral theft! This bee is far too big to crawl into the Hosta flower - so it heads up to the neck of the flower, cuts a neat hole and “steals” the nectar. Crafty 🐝
Constant current source is working well. Stable 250uA with a diode to add temperature stability.
May 29, 2025 at 9:55 PM
Constant current source is working well. Stable 250uA with a diode to add temperature stability.
This is definitely going to be a soldering challenge. It may be time to invest in a hot air station.
May 28, 2025 at 7:14 PM
This is definitely going to be a soldering challenge. It may be time to invest in a hot air station.
These Heltec LoRa V3 dev boards are really good for learning/testing ideas but with only 36 pins (many performing overlapping, incompatible functions) you rapidly hit limitations (eg external SPI conflicts with SX1262 radio chip). The docs are a bit limited too. So it’s Kicad time.
May 27, 2025 at 11:47 AM
These Heltec LoRa V3 dev boards are really good for learning/testing ideas but with only 36 pins (many performing overlapping, incompatible functions) you rapidly hit limitations (eg external SPI conflicts with SX1262 radio chip). The docs are a bit limited too. So it’s Kicad time.
My LoRa cryo-freezer monitor is coming on nicely. Doesn’t look much but PT100 RTD, battery monitor and door open sensor are all working. Power to RTD only switched on while reading. “Power is everything”, as they said on Apollo 11.
May 26, 2025 at 9:24 AM
My LoRa cryo-freezer monitor is coming on nicely. Doesn’t look much but PT100 RTD, battery monitor and door open sensor are all working. Power to RTD only switched on while reading. “Power is everything”, as they said on Apollo 11.
Help please! Can anybody identify this pcb-mounted wire press/clamp connector?
May 19, 2025 at 11:04 AM
Help please! Can anybody identify this pcb-mounted wire press/clamp connector?
Experimenting with a couple of LoRa sensors. The Heltec LoRa ESP32 v3 boards seem capable and easy to set up in the Arduino IDE. They come with neat 3D printed cases. The ESP32 ADC is not great - but with careful calibration it’s ok. Will be interested to see how long the 1100mAh LiPo lasts.
May 17, 2025 at 7:46 PM
Experimenting with a couple of LoRa sensors. The Heltec LoRa ESP32 v3 boards seem capable and easy to set up in the Arduino IDE. They come with neat 3D printed cases. The ESP32 ADC is not great - but with careful calibration it’s ok. Will be interested to see how long the 1100mAh LiPo lasts.
Hand soldering these SOT-23 3.3V LDOs is proving a challenge. I don’t have a hot air soldering gun so it’s a filed down standard tip and lots of concentration.
May 17, 2025 at 12:42 PM
Hand soldering these SOT-23 3.3V LDOs is proving a challenge. I don’t have a hot air soldering gun so it’s a filed down standard tip and lots of concentration.
Why on Earth is eBay asking for my National Insurance number?! Well, whatever the reason, forget it!
March 20, 2025 at 8:58 AM
Why on Earth is eBay asking for my National Insurance number?! Well, whatever the reason, forget it!
How come yours look majestic but this mess looks like they joined the two halves back to front? 🤣
February 9, 2025 at 3:55 PM
How come yours look majestic but this mess looks like they joined the two halves back to front? 🤣
At least yours has some feline dignity. Look at this mess!
February 1, 2025 at 11:15 PM
At least yours has some feline dignity. Look at this mess!
Birthday present to self :-) I’ve been looking for an HP5370A time interval counter for some, er, time - and this one is in mint condition. It even has all its feet! 🥳
January 23, 2025 at 9:05 PM
Birthday present to self :-) I’ve been looking for an HP5370A time interval counter for some, er, time - and this one is in mint condition. It even has all its feet! 🥳
Just (re)discovered my first (2005?) assembler dev board in the garage. This is an 8051 self-build kit by @paulstoffregen.bsky.social and it still works after ~20 years. So good that he still keeps the documentation available on his website. I think the afternoon just disappeared…
January 1, 2025 at 1:28 PM
Just (re)discovered my first (2005?) assembler dev board in the garage. This is an 8051 self-build kit by @paulstoffregen.bsky.social and it still works after ~20 years. So good that he still keeps the documentation available on his website. I think the afternoon just disappeared…
The odyssey continues. Apparently this type of WiFi shield has a build error - these two *tiny* J3Y transistors need replacing with two equally tiny MOSFETs so the level shifting works correctly.
December 23, 2024 at 10:21 AM
The odyssey continues. Apparently this type of WiFi shield has a build error - these two *tiny* J3Y transistors need replacing with two equally tiny MOSFETs so the level shifting works correctly.
I want to automatically set the datetime on an i2c RTC from my WiFi network. But first it seems I have to flash an updated firmware to the ESP8266 chip on a WIFI shield with an Arduino - its a really arcane process.
December 22, 2024 at 8:00 PM
I want to automatically set the datetime on an i2c RTC from my WiFi network. But first it seems I have to flash an updated firmware to the ESP8266 chip on a WIFI shield with an Arduino - its a really arcane process.
Having fun remaking some of my first Forrest Mims circuits from 1980. Even found an ancient Maplins receipt for some components :)
December 15, 2024 at 5:02 PM
Having fun remaking some of my first Forrest Mims circuits from 1980. Even found an ancient Maplins receipt for some components :)
BoscoMail (tm) has dropped this morning! 😄 @boscomac.bsky.social
December 7, 2024 at 8:36 AM
BoscoMail (tm) has dropped this morning! 😄 @boscomac.bsky.social
For the fourth time in under a week. Not including the time it was mid-delivered somewhere. UPS really is a bag of spanners.
December 3, 2024 at 7:19 PM
For the fourth time in under a week. Not including the time it was mid-delivered somewhere. UPS really is a bag of spanners.
When fixing the soft close mechanism on your kitchen pedal bin has been prioritised over debugging a ROM/CPU problem with your HP3455A digital voltmeter… 😩
November 30, 2024 at 11:24 AM
When fixing the soft close mechanism on your kitchen pedal bin has been prioritised over debugging a ROM/CPU problem with your HP3455A digital voltmeter… 😩
Successfully dumped the U8 ROM. It’s a little different from the one I downloaded from the internet (and which didn’t work). But if I use the dumped image to program the 2716 it runs the CPU test successfully. So I know my adapter PCB works. Progress. I can check all three ROMs for errors.
November 16, 2024 at 4:02 PM
Successfully dumped the U8 ROM. It’s a little different from the one I downloaded from the internet (and which didn’t work). But if I use the dumped image to program the 2716 it runs the CPU test successfully. So I know my adapter PCB works. Progress. I can check all three ROMs for errors.