Easily hackable LED RF remote control kits - a quick guide

[hydrogen maser]

I had seen these 433mhz LED RF remote kits on Amazon and thought they would be nice for some of my projects if they were hackable and they are. The kits typically come as a controller and remote, and some also come with some LED strip. 

example: https://www.amazon.com/RGBZONE-5V-24V-Controller-Wireless-Control/dp/B07D3KJN4B/ref=sr_1_8?

There are many variations of these "mini rf remote" things with different keypads and numbers of keys available anywhere quality products from China are sold Namely amazon, ebay, aliexpress, etc...

what each section does:

1) 6.7458mhz oscillator
2) MICRF00x receiver chip
3) power supply stuff - 5v in to 3.5v out
4) 24C02BN - 2048bit serial EEPROM
5) Anonymous micro-controller
6) A2SHB MOSFET's
7) output pin of the MICRF (Pin 5 - DO - data output)

All you need to do is lift pin 5 of (2) and run it to your micro-controller. The digital output is 3.5v logic but it is within the window of logic high for the microcontroller I am using and it works fine. If you are not using Arduino then you will need to find a library or write your own. If on Arduino then the RCSwitch library works just fine with this hardware. The codes are Protocol 1 - 24bits. The upper 16bits are the remote ID and the lower 8 bits are the button code. I just mask off the lower 8 bits of the 24bit code and ignore the 2 high bytes so any remote will work. The hardware is kind of interesting in that it has a serial eeprom and a micro-controller, I assume that this is because the micro is one of those 1 cent OTP jobbies and they need the serial eeprom to store the remote code and it just might also store some patterns or code for the micro, who knows?  These things get pretty low ratings on amazon -- lots of controller failures. The failures are likely due to drawing too much current and burning up the mosfets. They claim 12amps (4amps per channel) and that is much more than the A2SHB can handle (assuming the A2SHB's are even real and not knock-offs). People also complain about the controller losing the remote pairing. Neither of these problems are an issue for what I am doing with them and they make nice cheap remotes for little LED based projects.     

 





 

[hydrogen maser]

Final version - a little more work - solder three wires rather than one and cut the bottom 2/3rds of the board off. Now runs at 5V rather than 3.5V.

[SilverSolder]

Interesting hackable device, as you say.  What is the PWM frequency, and how many steps can you control (resolution)?

[hydrogen maser]

I don't know the specifics of the controller drive output as I just wanted it for the remote and receiver hardware and did not pay much attention to what was going on with the controller beyond making sure it worked before I started hacking on it. I have a batch of these ordered from ebay but it will be a while before they get here, will make a note to take a look at the output when they arrive. It would be easy to make these more robust so they could drive larger loads - just put some reasonably sized mosfets between the load and the outputs from this device.

[hydrogen maser]

I received my batch of 6 of these that I ordered from Ebay. It was $10 total including the shipping, for less than $2 each I think these things are a pretty good deal for what I want them for. I received "RevB" a different version of the hardware. This version has a surface mount oscillator and they have dropped the serial EEPROM. I thought the RF receiver chip was the MICRF007 as that chip was unmarked and it matched the data sheet for the 007. This version has a marked chip and it is not the 007, it is the WS480L, a chip that appears to be a clone of the 007 minus the AGC pin. The PWM frequency is 243 hz and there are 8 steps to the brightness control. Frankly I am not impressed with the output from this controller - there are just a few modes of the usual strobing of different colors and there is some pretty nasty ringing on the rising edges of the output pulses that makes its way all the way back through the power supply circuitry and into the incoming power rail - not nice. If you are just using it as a rf receiver and not diving a load with this thing then it works fine .