Three/Mono Phase Asynchronous Motor Simulator

When repairing stuff with a motor  the first question is:

“Is it the motor or is it the board that failed?”

For a recent Inverter Air Conditioner  board repair the following tool helped to answer that question.

 

sch

Simulate the circuit

The circuit can act as Induction Motor aka asynchronous motor .

Inverter Air Conditioners which use AC motors take the 220V from the grid and turn them into about 150V three phase AC which drives the motor.

ESP8266 – easy interrupts

While working on a current project i’ve faced an issue with code reuse. Espressif sdk allows only one interrupt handler for all GPIOs. That’s fine for monolithic code but since we like modular code a dispatcher comes handy.

The little inconvenience i’ve had was like this. I wanted to use the drivers/key.c code but it does use the data argument , so i’ve had to modify it to use a global variable. So i can call it from my own interrupt handler. And that is ugly.

KiCad change fields visibility utility

$ open devlog

I’ve back imported footprints for a .cmp file and I’ve misunderstood  kicad’s question about the imported footprints visibility, so all went visible.

And surprise, you can not edit visibility for all fields at once.

So  little utility was born – fixvis.

Usage is pretty simple:
./fixvis file.sch fieldid newval
where fieldid is:
0 - Reference
1 - Value
2 - Footprint
3 - Datasheet
4+ - custom
newval: 0000 = visible, 0001 = hidden

Apache websockets with proxy_wstunnel and mosquitto

Spend last weekend trying to make apache with proxy_wstunnel to work.
The solution recommended is to add this in the apache config:


ProxyRequests off

ProxyPass /mqtt ws://127.0.0.1:8082

ProxyPassReverse /mqtt ws://127.0.0.1:8082

But no matter what it is a no go. So, where is the problem?

It’s the libwebsockets it doesn’t understand custom http headers X-… but apache adds some.

To add support for them in the file lextable-strings.h append before the blank string :


“x-forwarded-server”,

“x-forwarded-for”,

“x-forwarded-host”,

ESP8266 – The Little Beast!

esp8266ex

The esp8266 chip is made by Espressif Systems.

ESP8266 is a highly integrated chip designed for the needs of a new connected world. It offers a complete and self-contained Wi-Fi networking solution, allowing it to either host the application or to offload all Wi-Fi networking functions from another application processor.

The chip have both certifications FCC and CE. You can sell your products to the mass market.

R&D Blog

Here you will read about the latest research and development at the lab.

I follow the latest trends in technology with bias to the Open Software and Hardware.

IoT

Current focus is on the Internet Of Things hype.

Why call it a hype?

A lot of people were doing it for the past decades – just like anything that gets conquered by the internet.

So now is time to connect it.

What to connect:

  • Your Door Bell
  • Your presence at every room
  • Your fridge
  • Your car
  • Your house
  • Your appliances
  • Your …. dog ?