IoT meets Stretch Limousine

Sometimes ago a customer asked us for help with the interior control of his Lincoln stretch limousine. The old solution was not so nice, there was no comfortable solution for the driver to control the lighting in the passenger cabin and he wants a remote control via mobile app in the future. Our Solution fulfills the following requirements:


  • control via touch screens with modern GUI
  • 2nd touch screen for the driver
  • communication of all components via WiFi
  • rugged design
  • simple to extend


We've used the ESP8266 - especially the Wemos D1 mini - for our solution. These modules comes with integrated USB  Module (makes programming easy), are supported by a big community, they need no boot time and are very simple and rugged. We've used the Arduino IDE for the programming of the firmware. Only the control board and touch screens are new - the old relay boards are used for this new solution again:


For the touch panels we've used Nextion touch screens. All pictures and other data of the GUI is stored in the Nextion touch itself. It's very easy to connect these touch screens to a microcontroller (in our case Wemos D1 mini too) via the UART.


GUI Car Interior conrol nextion
GUI on Nextion Touch

Both touch screens are connected to self made panel boards equipped with WEMOS D1. The panel board send data of touch events via UDP to the control board. The control board send the status of all switches, temperatures and the level of the fan via UDP back. These status protocols take care  that both touch screens and later the APP shows the same values...


All light effects are made with RGB led stripes connected to LED controllers. The control board can send infrared commands to control the color and brightness of the RGB stripes. Furthermore a fiber based "starry sky" is integrated in the ceiling. This starry sky is controlled by an special unit. We can control this unit via a RF remote control on the control board




Schaltplan Controlboard
control_board_schematic V01-02-00.pdf
Adobe Acrobat Document 264.6 KB
Schaltplan Paneldriverboard
panel_board_schematic V01-00-00.pdf
Adobe Acrobat Document 206.7 KB
source code ESP8266 control board
Compressed Archive in ZIP Format 5.0 KB
source code ESP8266 panel board
Compressed Archive in ZIP Format 2.5 KB

Write a comment

Comments: 24
  • #1

    imran (Monday, 12 February 2018 13:02)

    can send HMI file
    my email adress is

  • #2

    Gerd (Friday, 02 March 2018 18:31)

    hi can you send mi the HMI file please.
    i will learn from your file.
    i will it not copy!!
    that good
    greats redard Gerd
    my English is not so good sorry

  • #3

    Gerd (Friday, 02 March 2018 18:32)

    hi my Email is

  • #4

    saichon (Monday, 04 June 2018 15:13)

    please send file HMI Nextion touch screens
    to Email :

  • #5

    Gerd (Friday, 21 December 2018 16:23)

    hi can you send me please the HMI File

  • #6

    Gerd (Friday, 21 December 2018 16:24)

    Sorry to

  • #7

    skr (Wednesday, 16 January 2019 12:51)

    Great projet!!
    Please send file HMI Nextion touch screens
    my email adress is

  • #8

    Mortz (Wednesday, 27 February 2019 21:06)

    Thats great
    Please send file HMI nextion touch screens
    My email address is
    Best wishes

  • #9 (Saturday, 13 April 2019 13:41)

    is HMI avalible? Thank you

  • #10

    mihai andreiu (Friday, 26 April 2019 18:22)

    Please send hmi nextion file.
    Thank you

  • #11

    Brian (Saturday, 04 May 2019 11:55)

    I would also appreciate the Nextion file, if you are willing to send it.
    Thank you

  • #12

    Gerd Michel (Friday, 17 May 2019 13:48)

    hi can you send mi the HMI file please.
    i will learn from your file.
    i will it not copy!!
    that good
    greats redard Gerd
    my English is not so good sorry
    my mail is

  • #13

    Fabio (Thursday, 26 December 2019 16:06)

    Puoi inviare file hmi grazie

  • #14

    Cris B (Saturday, 04 April 2020 05:12)

    Hi, nice GUI. Is it available or u can send me to ?

  • #15

    Andre (Saturday, 04 April 2020 18:03)

    Hello, excelent project !! Can You please send HMI file just for me.
    Thank You !

  • #16

    Murat (Sunday, 12 April 2020 14:55)

    Hello, i begined learn to nextion displays. your project is realy perfect. İt will help in my education. Thank you for sharing.If posibble, can you sen me hmi. file.I wish you healthy days.Murat

  • #17

    Murat (Sunday, 12 April 2020 14:59)

    its my e-mail

  • #18

    Davide Betti (Sunday, 10 May 2020 10:28)

    Ciao Hartmut!
    I kindly ask you if you can send at:
    the HMI file relevant to the ESP8266 HVAC Nextion board.
    Thanks and greetings from David

  • #19

    macekzel (Saturday, 28 November 2020 16:48)

    Please send file HMI nextion touch screens
    My email address is
    Best wishes

  • #20

    tony (Tuesday, 16 February 2021 16:08)

    sehr gute Arbeit
    ich hätte es gern eine Anleitung wie man Nextion-GUI in Samsung(Android)-Smartphone übertragen kann.
    vielen Dank

  • #21

    Marco (Saturday, 27 February 2021 19:02)

    Hi people beautiful project can I have hmi file please or does some one have it really appreciated mail or thanks a lot people

  • #22

    krishna kumar (Friday, 07 May 2021 07:53)

    can you please send me the HMI file

  • #23

    Murat (Monday, 13 December 2021 21:04)

    Can you send ne the hmi file
    Thank you

  • #24

    Marco (Friday, 31 December 2021 07:06)

    I'm looking for limo touch systems for my limousine if u can help me . 1415-573-4961. Thank u


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