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Readme.md

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+# Autonomous Controller
+
+**This writeup is still WIP**
+
+## The Idea
+
+I bought a standing desk from Autonomous (Smart Desk 2 Home Office). After setting it up, I was wondering how the controller and the table/motor controller communicate with each other.
+
+## ToDo
+
+- More detailed writeup
+- Test findings by implementing my own controller on a uC (probably ESP32)
+
+## First impressions
+
+Opening up the controller reveals nicely labeled PINs.
+
+![IMG_20200304_195541](/home/stefan/Dokumente/Autonomous/IMG_20200304_195541.jpg)
+
+Thus we now only know that UART is used to transfer data, but also which wire carries which signal:
+
+| color  | function |
+| ------ | -------- |
+| red    | sleep(?) |
+| orange | GND      |
+| green  | TX       |
+| yellow | RX       |
+| blue   | 5V       |
+
+After some trying out, I found the baudrate: 9600
+
+Height-Profiles are not saved on this controller - they are stored in the desk.
+
+The controller board uses a STC12C5612AD controller. It features:
+
+- 3,5-5,5V
+- 8 Bit
+- 23 I/O pins
+- 1x UART
+- 768 Bytes RAM
+- 4K-30 KB program memory size (according to datasheet)
+
+[Datasheet](https://www.datasheet4u.com/datasheet-pdf/STC/STC12C5612AD/pdf.php?id=853205)
+
+## My Setup
+
+I used a DSView Logic Analyzer which I bought here [from Banggood](https://www.banggood.com/DSLogic-Logic-Analyzer-16-Channels-400M-Sampling-USB-based-Debugging-Logic-Analyzer-p-1200454.html).
+
+I did not dismantle the controller that shipped with my desk. Instead, I asked the customer support for a spare one / replacement. They shipped it to me for 27€.
+
+I opened up the casing (standard screws) and found a nicely labeled PCB where I could attach the probes to. 
+
+## Received Data
+
+When no button is pressed, we keep receiving (repeating):
+
+Base Message:
+
+0x98, 0x98, 0x00, 0x00, (2 more Bytes, indicating current height)
+
+
+
+Height indication:
+
+Height: 29.05
+
+Last 2 Bytes of Message: 0x4B, 0x4B
+
+
+
+Height: 29.09
+
+Last 2 Bytes of Message: 0x4C, 0x4C
+
+
+
+Height: 30.03
+
+Last 2 Bytes of Message: 0x4D, 0x4D
+
+
+
+Height keeps increasing in steps of 0.4
+Message keeps increasing by 1
+...
+
+
+
+Height: 48.00
+
+Last 2 Bytes of Message: 0x7A, 0x7A
+
+
+
+Height: 48.40
+
+Last 2 Bytes of Message: 0x7B, 0x7B
+
+## Transmitted Data
+
+### Pressing up
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x02, 0x02
+
+(keep going with end 0x02 as long as the button is pressed)
+
+### Pressing Down
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x02, 0x01
+
+(keep going with end 0x01 as long as the button is pressed)
+
+### Pressing 1
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x04, 0x04
+
+(keep going with end 0x04 as long as the button is pressed)
+
+### Pressing 2
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x08, 0x08
+
+(keep going with end 0x08 as long as the button is pressed)
+
+### Pressing 3
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x10, 0x10
+
+(repeating 0x10 as long as the button is pressed)
+
+### Pressing 4
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x00, 0x20
+
+(repeating 0x20 as long as the button is pressed)
+
+### Pressing M
+
+0xD8, 0xD8, 0x66, 0x00, 0x00
+
+0xD8, 0xD8, 0x66, 0x40, 0x40
+
+0xD8, 0xD8, 0x66, 0x40, 0x40
+
+(repeating 0x40 as long as the button is pressed)
+
+## Analyzing the protocol
+
+- Controller->Desk: Every message contains 5x2 bytes
+- Controller->Desk: Message always starts with 0xD8, 0xD8, 0x66
+- Controller->Desk: Last 2 Bytes always repeat
+- Desk->Controller: Every message contains ... bytes
+- Desk->Controller always starts with ...
+- Every button corresponds to 1 bit in the message
+
+  - 7 buttons, 8 bit -> highest bit unused (?)
+- The controller sends the current state of the buttons after receiving a message from the desk
+
+