Uplift Desk Automation

Message Syntax 
 Transmit 
 A transmitted message has the following syntax. 
 0xF1, 0xF1, <cmd>, 0x00, <crc>, 0x7E
 
 
 0xF1, 0xF1 indicates the message start 
 cmd is one of:
 
 0x01 - Up 
 0x02 - Down 
 0x03 - Save preset 1 
 0x04 - Save preset 2 
 0x05 - Recall preset 1 
 0x06 - Recall preset 2 
 0x07 - Sync 
 0x25 - Save preset 3 
 0x26 - Save preset 4 
 0x27 - Recall preset 3 
 0x28 - Recall preset 4 
 0x2B - Stop 
 
 
 crc is the sum of the bytes at index 2 and 3. 
 0x7E indicates the end of message. 
 
 Receive 
 A received message has the following syntax. 
 0xF2, 0xF2, <cmd>, <len>, <data...>, 0x0F, <crc>, 0x7E
 
 
 0xF2, 0xF2 indicates the message start 
 cmd is one of:
 
 0x01 - Height value 
 0x25 - Preset 1 height 
 0x26 - Preset 2 height 
 0x27 - Preset 3 height 
 0x28 - Preset 4 height 
 
 
 len indicates how many messages will be sent next, excluding the CRC and EOT. 
 data will contain the incoming data values, explained for height readings below. 
 0x0F - Unknown 
 crc will be the sum of bytes at index 2 up to the CRC. 
 0x7E indicates the end of message. 
 
 Example: Received Height Reading 
 When a new height value comes in, the message will look something like this: 
 0xF2, 0xF2, 0x01, 0x03, 0x01, 0x1B, 0x0F, 0x2F, 0x7E
 
 In this case, the desk was at 28.3". Here is how we can calculate that. 
 
 First off, the command is 0x01 , so we know we're about to receive height data. 
 The next byte tells us to listen for 3 data bytes. 
 The relevant data comes in as 0x01, 0x1B . This will be converted to a height value later. (Unclear what 0x2F does here) 
 Then, we add all of the previous bytes (other than the header) to verify the CRC is correct. 0x01 + 0x03 + 0x01 + 0x1B + 0x0F = 0x2F 
 The actual height is a two-byte word, so the first number needs to be bitshifted. In this example, we received 0x01, 0x1B , so the height calculation looks like: 0x01 << 8 | 0x1B = 283 . 
 Divide the received value by 10 to convert to inches. The result is 283 / 10.0 = 28.3in . 
 
 Preset Heights 
 A sync request will get a response with cmd 0x25 , 0x26 , 0x27 , 0x28 , then a regular 0x01 height. The 0x01 value is understood, but the preset height values are not yet understood. There is a two-word response, and the words change with the saved height value. The second word seems to be a decimal. I have not yet determined how to parse these into the stored heights. 
 Here is a table of example values. For heights that are the same, I would slightly adjust the table height and save again. The changed values suggest these are more specific than inches. 
 
 
 
 Height 
 data[4] 
 data[5] 
 
 
 
 
 25.3 
 20 
 5 
 
 
 25.3 
 20 
 8 
 
 
 25.3 
 20 
 11 
 
 
 25.3 
 20 
 54 
 
 
 28.3 
 25 
 62 
 
 
 28.3 
 25 
 67 
 
 
 28.3 
 25 
 82 
 
 
 38.? 
 42 
 207 
 
 
 39.9 
 45 
 153 
 
 
 39.9 
 45 
 156 
 
 
 40.0 
 45 
 168 
 
 
 42.4 
 50 
 7 
 
 
 42.8 
 50 
 188 
 
 
 42.9 
 50 
 231 
 
 
 43.0 
 51 
 8 
 
 
 43.1 
 51 
 27 
 
 
 43.2 
 51 
 104 
 
 
 50.8 
 64 
 161 
 
 
 
 References 
 Hardware 
 
 "2ANKDJCP35NBLT Bluetooth Box by ZHEJIANG JIECANG LINEAR MOTION TECHNOLOGY CO., LTD" . (2018, January 25). FCC ID. Retrieved January 19, 2021. 
 Jiecang Bluetooth Dongle Product Listing . Retrieved January 19, 2021. 
 
 Images from /u/deadman96385 
 
 https://imgur.com/a/MUbXwnM 
 https://i.imgur.com/DyMf3Ee.jpg 
 https://i.imgur.com/KtsWpVQ.jpg 
 https://i.imgur.com/BS62C1E.jpg 
 https://i.imgur.com/woWoQMe.jpg 
 https://i.imgur.com/Lta5Nab.jpg 
 
 Software 
 
 Justintout. (2020, April 16). GitHub - "justintout/uplift-reconnect: A Flutter app to control Uplift desks with Uplift Connect BLE modules installed" . GitHub. Retrieved January 19, 2021. 
 Deadman96385. (2020, March 6). "uplift_desk_controller_app/BluetoothHandler.java at a58bcadfb77ac993751758465f1cf20f71d6d8fd · deadman96385/uplift_desk_controller_app" . GitHub. Retrieved January 23, 2021. 
 Phord. (2021, August 12). "phord/Jarvis: Hacking the Jarvis standup desk from fully.com for home automation using an ESP8266 arduino interface" . GitHub. Retrieved December 5, 2021. 
 Ramot, Y. (2015, February 4). "UpLift Desk wifi link" . Hackaday.io. 
 Horacek, L. (2019, April 14). "Standing desk remote control" . Hackaday.io. 
 Hunleth, F. (2019, January 18). "Nerves At Home: Controlling a Desk" . Embedded Elixir. Retrieved January 2021.