Help needed - SSR switch / SCR dimmer

[stedew]

@ksga
well i suggest you use google for this (the trafo). Also your link provide schema and code not so bad as a start. also there is a module (the Bluetooth classs) that set the power output from a literal in %. This is exactly what you need to bind it to Mysensor lib...
this is what i found on ebay Example link
This trafo does not provide much power but it is small and maybe sufficiënt for powering the arduino.
There is one catch when using a trafo : it introduce a phase shift so you must provide e methode (i believe a fix constant will do in most cases ) to trim the "offset" of the zero crossing.
As i am not a specialist on mysensors internal structure but for a atmega328p (uno) TCCR1A is used inseverall places ,for analog write Altsoftserial (RS485) etc. So you must be sure not to re-use the timer it will behave strange. Same is for the attachInterrupt function it is used in hwSleep function. As there are only 2 HW irq's you must choose the "right" one in most designs i believe irq 1 is used for the NRF24l01 /RFM69 so choose the other one on your mcu . For all these reasons i believe it will take many hours off testing to get the dimmer "glitch" free.
I believe for this resons it is better to offload the mcu and use a dedicated chip/mcu when you want to use Mysensors in your dimmer.

[Koresh]

Hi. Only my 5 cents...
Do not doubt. It is not possible to use the mysensors library (or another serious software) and to control a dimmer from one atmega328. Your controller will omit dimmer ISR during handling radio interrupts. I solved this problem using external attiny13 to control triac (it was a little challenge because attiny13 has only one timer and very little rom so I'd written program from scratch without arduino). It is not only one solution but it works and it is low cost. In this case we can use standard atmega328 as main controller (program it as standard arduino) and attiny13 as hardware controller. I have real prototype and may be I will route the board when will have time.

[ksga]

@Koresh
Sounds like a good plan. Have you shared the code/design anywhere?

@stedew
Thanks fo the link :)
Browsed Ali and ebay, but shipping is killing me on these trafos.
Got me wondering... a lot of cheap AC-DC transformers are flooding these sites in 5-12V variants.
Why not just take one of those apart - salvage the trafo and scrap the rest?

I only need a few hundred mA to run arduino, radio and relay...

This is the kind of stuff I'm talking about (claims to be able to deliver 2A 5VDC - but that would only be if you had to start a fire...):

[ksga]

@Koresh
Does your solution looks anything like this?

[Koresh]

@ksga said:

@Koresh
Does your solution looks anything like this?

Yes, my solution loks like this, but I use cheaper controller and digital interface between atmega328 and attiny13.

[FutureCow]

Isn't this something to get the same results: https://forum.mysensors.org/topic/5408/ultra-small-esp8266-node-with-2-channel-relay-temperature-dimmer-project

[ksga]

@FutureCow
Looks like it. But no code published...
Also - is the ESP8266 capable of handling the interrupts without messing up the timing when it is also responsible for communicating with the controller and the rest of the stuff??

[ksga]

@Koresh
Cool.. could you share the code?

[Koresh]

@ksga said:

@Koresh
Cool.. could you share the code?

New year holidays is the busy time :) I really want to start production of many boards within the coming weeks (my fulltime job projects and mysensors boards too). So I can't promise to share this project very soon (I am not sure you are interest in a code written in hurry and untested prototype). But I will try to do it asap :smirk:

[ksga]

@Koresh
No worries - all help is appreciated - fast or slow :)