LINBUS

2 Articles

Heated Seat controls

Retrofits Done Right: Physical Controls For Heated Seats

November 24, 2025 by 37 Comments

We’ve all owned something where one tiny detail drives us nuts: a blinding power LED, buttons in the wrong order, or a beep that could wake the dead. This beautifully documented project fixes exactly that kind of annoyance, only this time it’s the climate-controlled seats in a 2020 Ram 1500.

[projectsinmotion] wasn’t satisfied with adjusting seat heating and ventilation only through the truck’s touchscreen. Instead, they added real physical buttons that feel just like factory equipment. The challenge? Modern vehicles control seats through the Body Control Module (BCM) over a mix of CAN and LIN buses. To pull this off, they used an ESP32-S3 board with both CAN and LIN transceivers that sits in the middle and translates button presses into the exact messages the BCM expects.

The ESP32 also listens to the CAN bus so the new physical buttons always match whatever setting was last chosen on the touchscreen, no mismatched states, no surprises. On the mechanical side, there are 3D-printed button bezels that snap into blank switch plates that come out looking completely stock, plus a tidy enclosure for the ESP32 board itself. Wiring is fully reversible: custom adapters plug straight into the factory harness. Every pinout, every connector, and every wire color is documented with WireVis diagrams we’ve covered before, making this an easily repeatable seat-hack should you have a similar vehicle. Big thanks to [Tim] for the tip! Be sure to check out some of our other car hacks turning a mass produced item into one of a kind.

Ikea Standing Desk Goes Dumb To Smart On LIN Bus

February 10, 2017 by 27 Comments

IKEA’s products are known for their clean, Scandinavian design and low cost, but it is their DIY or “assemble it yourself” feature that probably makes them so popular with hackers. We seem to receive tips about IKEA hacks with a consistent regularity. [Robin Reiter] has a Bekant Sit/Stand motorized table with buttons to raise and lower the surface, but it doesn’t have any memory presets. That’s a shame because it requires a lot of fiddling with the up/down buttons to get it right every time. It would be nice to press a button, go grab a Coffee, and come back to find it adjusted at the desired height. With a little bit of hacking, he was able to not only add memory preset buttons, but also a USB interface for future computer control.

The existing hardware consists of a PIC16LF1938 micro-controller with two buttons for movement control and a LIN bus  protocol which communicates with the automotive grade motors with integrated encoders that report position values. After a bit of sniffing around with his oscilloscope and analyzer, he was able to figure out the control codes for the motor movements. For some strange reason, however, the LIN signals were inverted, so he had to introduce a transistor signal inverter between the PIC master and the Arduino Nano that would act as a slave LIN node. Software was made much easier thanks to an Arduino library developed by [Zapta] for the LIN Bus signal Injector, The controls now have four buttons — two to replicate the original up/down movements, and the other two to act as memory presets.

The code, schematic and a simple wiring layout are posted on Github, in case there are others out there who’d like to replicate this hack. Check out the video after the break where he gives a walk through the code.

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