8 Replies Latest reply on Jun 29, 2018 11:55 PM by craigst

    Reverse engineering Control panel to control with a pi

    craigst

      I have a led bar with a control panel, has 8 buttons and a led light mimic of what the leds are doing on a panel i wana control it creating a python gui on a touchscreen

       

      im need to data reverse engineering so far i have a 12+ a negative and 1 signal wire

       

      What do i need and what best way to make a clone and put gui over the top ?

       

      thanks for any advice

        • Re: Reverse engineering Control panel to control with a pi
          craigst

          Update :

          i have done an oscilloscope check connected to negative and signal and got a clean repeating signal on 10v 10ms at 396-398mhz

           

          long pause then maybe 10-15 bit code (even when off) i have a DSO NANO v3 , not used it much and still learning so need a lil guidance being able to re send code on a pi (python script)

           

          any help or how to get started

           

          https://www.youtube.com/watch?v=AIlzMVjNaCk

          1 of 1 people found this helpful
            • Re: Reverse engineering Control panel to control with a pi
              shabaz

              Hi Craig,

               

              You're doing it right, examining the signal. Unfortunately it could be any encoding scheme, so all that can be practically done (based on the information so far) is just to try to look for patterns and try to decipher it. It could be tedious work and may take a long time : (

              Or, you could ask the manufacturer, they may be kind enough to provide some information. Not all manufacturers will though : (

              The device likely has custom code in a microcontroller, so there is no way to predict what the encoding scheme is from the photos. A cheap logic analyzer could be helpful, but the problem is that if you're seeing 10V then most logic analyzers will not be compatible, so you'd need to divide down the voltage with a couple of resistors before hooking it up to a logic analyzer.

              3 of 3 people found this helpful
            • Re: Reverse engineering Control panel to control with a pi
              Roger Wolff

              On the picture of the bare PCB on the right you see a voltage regulator. then in the middle a CPU and on the left a shift register. The small 8pin chip is an EEPROM.  So the CPU will have control over the 20 leds.

               

              When you report measuring near 400MHz with a DSO nano, something is going wrong between your electronics and it being reported here on this forum. So I also doubt the "10V signals" that you mention: I expect microcontroller-compatible signal levels because the signal wire goes directly from the connector into the microcontroller.

              You can achieve your goal through two possible routes. Which one is going to be most easy I don't know in advance.

               

              The first route is to analyse the signal. and reproduce that on the pi.


              The other route is to simply wire the pi to emulate button presses on buttons.  Double check: All switches have a connection to GND, and double check that they have a connection to the little CPU.

               

              Maybe a little more can be learned from the name of the CPU. The EEPROM I can read the text on it in your picture, but not of the other chips. Can you take another picture where we can read the numbers on the other chips?

               

              Note that reverse engineering is not a skill that you can explain to someone step-by-step. It requires someone with a bit of intelligence doing the actual job. There have been a few stories on hackaday that were listed because the person did some clever reverse engineering. Read up on those articles is what I'd suggest.

              2 of 2 people found this helpful
                • Re: Reverse engineering Control panel to control with a pi
                  craigst

                  I'll check the voltage I'm guessing I'm wrong as I didn't test voltage just set 10v on ossiloscope to make it clearer , I Wana get rid of that controller make my owner in form of GUI on touch screen controller I'm guessing my discription sucks that controller controls a beacon bar on the roof of my van 6 strips at the back and 6 at front and 1 eather side of the bar the only way to control the beacon bar is with this control panel ( no on off switch ) and my ultimate goal using relays and this controller is to have a GUI interface to control the van top to bottom clean no buttons or switch's and then move it to a large center touch screen in middle of van for stereo custom 3d printed parts so will be like Tesla but I got year before I get brand new van and will use current beacon bar I have due to being brighter than what out police force have , I can require a van or car to do what I want as it's simple relay job for each part

                  • Re: Reverse engineering Control panel to control with a pi
                    craigst

                    Main cpu has no numbers on it unfortunately 1 check seems to control or read buttons, other controls LEDs on controller , I not sure it this helps but reading signals they seem to not be set by button press off seems to send a signal turning it on changes the wave a little and sends it over and over I didn't see and spike or wave change on button press, I could be wrong tho

                  • Re: Reverse engineering Control panel to control with a pi
                    craigst

                    Thanks guys , yes I set 10v my self lower I set it smaller lines got to read , I have emailed the manufacturer no response but looks like many companys use the same controller , ok so the controller controls easy strip , that's cool meaning I can choose and make my own patterns

                     

                    I'm very new only can go by what I've learnt online so I'm happy to take time a learn I only see the long clear signal before the Patten ( I'll post picture when I learn how to save them ) voltage regulator I'm guessing to drop from 12/24v but I'll test that , anyone know if the oscilloscope I have can use a computer connected to it ? Also logic analyer and information ? So far I got 14 led strips , I think the company tryed to mod it them selfs for the side flood lights but they made it control the side beacon instead

                     

                    UPDATE : did voltage check drops to 5v

                    added the scope picture when beacons are off

                     

                    Thank you guys so much for you insight I will keep you all updated on my progress