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).

ProsConsUnknowns
Partnership with FinderDigital I/O uses 0-10VDC, not “standard” 24VDCHow will programming support for IEC 61131-3 PLC languages work? Via existing IDE?
DIN rail mountAnalogue inputs use 0-10VDC, not “standard” 4-20mACan programming be done over Ethernet?
IEC 61131-3 PLC language supportI/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:

ProsConsUnknowns
Partnership with FinderDigital I/O uses 0-10VDC, not “standard” 24VDCHow will programming support for IEC 61131-3 PLC languages work? Via existing IDE?
DIN rail mountAnalogue inputs use 0-10VDC, not “standard” 4-20mACan programming be done over Ethernet?
IEC 61131-3 PLC language supportI/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.

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)

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.

Screenshot of the TempMonHTTP webpage. Yes, it gets hot in my walk in robe where the home LAN switch is…

Check out the code at https://github.com/gjhmac/TempMonHTTP.

Ahead of their time…

One of my tasks as an undergraduate in the engineering firm I was working at was to look after the website. Back then knowing a little HTML and how to use FTP wasn’t as common as it is now.

The web hosting company we used provided quite detailed logs for all of our virtual visitors. By looking at the IP addresses in the logs it was possible to speculate (the key word here being speculate) which company the visitor worked at.

Our sales and marketing guy caught wind of these logs and suggested we send emails to the companies we suspected had had one of their employees visit our site asking if we could be of any assistance or if they required any further information.

I explained that a) we didn’t 100% know that they had visited and b) this raised all sorts of privacy issues. Plus to me this sort of practice was creepy and not how the Internet was supposed to work.

How naive was I?