Designing an RF remote controlled lightswitch with dimmer - Page 1
Forum section: electronics / beginners

author: axero
author_rank: Regular Contributor
timestamp: January 08, 2014, 12:19:04 am
content: ObjectiveI want to design a 5 or 6 channel light switch with the capability of taking a load of at least 500W per channel where at least two of these channels are dimmable. An ideal configuration would have one remote control and two receivers.Research backgroundA week ago I reverse engineered such a circuit in order to troubleshoot the power supply side. The thread about this is found here:https://www.eevblog.com/forum/beginners/diagnosing-a-rectifier-circuit/I also took some pictures of the PCB of the device. It consists of a mainboard and some kind of a daughterboard. The mainboard contains the PSU, some relay circuitry and the CPU (which I have no clue what it is. The daughterboard (RF receiver module) contains the receiver circuit coupled with some kind of antenna (a white cable).The main boardThese are images 1,2 and 3 from top to bottom...The receiver moduleThese are images 4,5 and 6 from top to bottom...The transmitter moduleThese are images 7 and 8 from top to bottom...The 'main chip' (DIL18) of the transmitter module is a W0369DGP0103 circuit.The trouble that I have is to identify the 14-pin DIL chip on the mainboard that is right underneath the RF receiver module that assumedly is the CPU or control logic circuit.The label side of it is completely blank, all I know is that $+V_{cc}$ (+5V) is fed into pin 4 and $-V_{cc}$ or GND is on pin 11. Some kind of reference voltage of ~2.5V seems to be fed into pin 2. The circuit has 4 channels for controlling light sources located on pins 1, 12, 13 and 14 where three of them toggles LEDs (CH2-CH4; all three are paired, i.e. one button push on the remote turns them all on or all off) and one toggles a mechanical relay. The signal from the RF receiver module goes into pin 8.The SMD8 chip on the receiver module (daughterboard) is a 358 from STMicroelectronics and the module is fed with a 5V voltage.Any ideas as to what kind of a chip that is would be appreciated, I hope it is not an ASIC.That a partly dimmable 6-channel RF module is achievable and not that expensive to build is not so hard to realize when searching through ebay. I got the following hits there:eBay search query for RF light switcheshttp://www.ebay.com/sch/i.html?_odkw=technics&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xrf+controlled+light+switch&_nkw=rf+controlled+light+switch&_sacat=0"Plain vanilla" 4 and 6 channel 12V switcheshttp://www.ebay.com/itm/12V-Four-4-Channel-Way-RF-Remote-Control-Switch-for-Light-/151097760649?pt=Home_Automation_Controls_Touchscreens&hash=item232e20db89http://www.ebay.com/itm/12V-6-Channel-Way-RF-Remote-Control-Switch-for-Light-/260739698681?pt=Home_Automation_Controls_Touchscreens&hash=item3cb54c0ff93-way 240V switchhttp://www.ebay.com/itm/AC-220-240V-3-Way-RF-Light-Wall-Control-Switch-Digital-Smart-Remote-Controller-/310827949461?pt=Home_Automation_Modules&hash=item485eca1d951 channel dimmable control:300Whttp://www.ebay.com/itm/300W-30M-RF-Remote-Control-Switch-For-Lights-AC200-240V-Dimmable-F-Incandescent-/320919118567?pt=Home_Automation_Controls_Touchscreens&hash=item4ab84522e72000Whttp://www.ebay.com/itm/AU-Standard-Light-Touch-Screen-Wall-Dimmer-Switches-1Gang-1Way-RF-Remote-Control-/271344897906?pt=AU_Building_Materials&hash=item3f2d6a8f72One remote control 2 receivers totalling 4 channelshttp://www.ebay.com/itm/12V-4-Channel-RF-Control-Switch-Relay-Output-2-receivers-2-remotes-for-light-/261046507671?pt=Home_Automation_Controls_Touchscreens&hash=item3cc7959897Any suggestions?note that the "$" or "$$" brackets are for typesetting the math inside with mathjax (www.mathjax.org)

author: Unknown
author_rank: Unknown
timestamp: January 08, 2014, 12:34:44 am
content: Your images aren't exactly where you say they are.Quote from: axero on January 08, 2014, 12:19:04 amYeah, that doesn't work.

author: axero
author_rank: Regular Contributor
timestamp: January 08, 2014, 02:29:50 pm
content: That's strange because the images show up just fine on my computer. I have now changed image hosting website to imageshack.us hopefully it works better now.If mathjax typesetting doesn't work, that's nothing I can do about unfortunately. The site admin either needs to add a few mathjax lines into the web page or end users can add these lines with a greasemonkey script.