This is awesome. I have a White Pebble 2 Duo on the way.
Category Archives: Engineering
Solved: Initial Arduino Opta setup woes
I had great difficulty getting my Arduino Opta set up and working using the Arduino PLC IDE – whatever I tried I got the “Cannot download Sketch file (error code: 1)” error.
I finally had success using the plain Arduino IDE to do the initialization and then switching to the Arduino PLC IDE. The final step was changing the Modbus address to 247.
It probably shouldn’t be that tricky….
Updated: Arduino Opta
I ordered an Arduino Opta (RS485 version) and it has arrived – stay tuned for upcoming posts!
In the meantime, I’ve updated my initial review as it has been confirmed that the digital inputs support 24VDC. Programming support for IEC 61131-3 PLC languages has also been clarified (no MacOS support sadly).
Pros | Cons | Unknowns |
---|---|---|
Partnership with Finder | ||
DIN rail mount | Analogue inputs use 0-10VDC, not “standard” 4-20mA | Can programming be done over Ethernet? |
IEC 61131-3 PLC language support | I/O expansion options? (What does the “AUX” port do?) | |
Digital inputs support 24VDC (see here) | ||
Beefy relay outputs with dedicated commons | ||
Modbus-TCP and Modbus-RTU support | ||
Input power supply is 12-24VDC | ||
IP20 | ||
-20 °C to +50 °C temperature operating range |
Initial Thoughts: Arduino Opta
Arduino have announced a new micro PLC, the Opta, and while some details are unclear, it seems like a pretty neat product. Here are my initial thoughts:
Pros | Cons | Unknowns |
---|---|---|
Partnership with Finder | Digital I/O uses 0-10VDC, not “standard” 24VDC | How will programming support for IEC 61131-3 PLC languages work? Via existing IDE? |
DIN rail mount | Analogue inputs use 0-10VDC, not “standard” 4-20mA | Can programming be done over Ethernet? |
IEC 61131-3 PLC language support | I/O expansion options? | |
Beefy relay outputs with dedicated commons | ||
Modbus-TCP and Modbus-RTU support | ||
Input power supply is 12-24VDC | ||
IP20 | ||
-20 °C to +50 °C temperature operating range |
I’m hoping to buy one.
Apple Product Ranges and Processor Architectures (Updated)
Apple Product Ranges and Processor Architectures
Recently Read: Every Tool’s a Hammer by Adam Savage

I have just finished reading Adam Savage’s book “Every Tool’s a Hammer” (ISBN 9781471186004). It was a thoroughly entertaining and informative read and I highly recommend it.
The section on lists particularly resonated with me. I use a similar system at work: an empty box indicates a yet to be started task, a box with a line through it a task that has been started in some form and a filled in box indicates a completed task.
However my favourite part was a new word I learned – ferroequinologist!
Planes I have flown in (updated to include A330 and Dash 8)
- Fokker 100 (Alliance Airlines, Network Aviation);
- Boeing 737-400 (Qantas/QantasLink);
- Boeing 737-800 (Qantas, Virgin Australia);
- British Aerospace 146 (QantasLink);
- Boeing 717-200 (QantasLink);
- Embraer E-Jets E-190 (Virgin Australia);
- Embraer EMB 120 Brasilia (Network Aviation);
- Fokker F70LR (Network Aviation);
- Airbus A320 (Virgin Australia);
- Saab 340 (Regional Express Airlines);
- Airbus A330-200 (Qantas);
- Dash 8 300 (QantasLink);
- Dash 8 400 (QantasLink).
TempMonHTTP
For a while I’ve been tinkering around with a simple project – an Arduino-based temperature (and humidity) monitor that outputs a webpage on my home LAN. The Arduino I used was the Freetronics EtherTen, a quality product.

Check out the code at https://github.com/gjhmac/TempMonHTTP.
Recently Read: Humble Pi by Matt Parker

I have just finished reading Matt Parker’s book “Humble Pi: A Comedy of Maths Errors” (ISBN 9780241360194). It is a very entertaining and enjoyable read. Matt’s background research and analysis on each of the errors is excellent.
Recommended reading for anyone with an interest in Mathematics, Engineering, Computers…