Serial control discussion and gallery

[DJPoulter]

Reading through #12 I couldn't seem to find the best solution to this so asking it here. But what are peoples recommendations on a controller for serial control? I was thinking of just using a D1 mini.

And then to follow it up would the best solution be to run connect the 3 pins from the programming header and run the cable out to the controller? Or has someone worked out a way to get power and fit a controller in the box itself?

[gcormier]

I would definitely not recommend tapping the megadesk for power. The thermal implications probably aren't great as linear regulators are used, which produce heat to drop the 30V down to 12V and 5V. This is OK as our consumption is very low - about 15mA.

Adding something that consumes 10 the power will be too much heat inside the enclosure.

The new PCB version (just some layout changes, nothing new) actually has silkscreen now that says not to use the power for any other peripherals since more and more folks are interested in the serial stuff.

I would suggest you could tap RX/TX/GND/24V from the megadesk, and then wherever it is going, have your own component to go from 24V to whatever voltage is needed by your accessory board.

[DJPoulter]

Okay perfect, my Megadesk should be arriving soon. I am keen to get tinkering with it.

[Will1604]

Unsure if adding a Bluetooth LE control option is off topic for this discussion, but going for it anyway.

The Bluefruit LE UART looks possible. The question of flow control may or may not be an issue depending on circumstances.

The current measurements show average current: 1.86mA, peak current: 15.2mA, More like 2x power than the 10x for Wifi options. How does providing that via the programming header seem?

For the "tap RX/TX/GND/24V from the megadesk" route. Any suggestions on options for the 24V. Simplest might be a short breakout cable with 2.54mm headers between megadesk and the power cable. Details on using a DC Buck in issue #58 would complete the picture.

[gcormier]

2mA average consumption should be ok.

For tapping, yeah I think a 2.54mm cable is easiest. Either make your own completely, or something like these https://www.amazon.ca/Spektrum-Futaba-Harness-Splitter-Airplane/dp/B07PHDYZXN (I don't know if these will work as the RC ones I have have 2 rounded edges on the black housing)

[gcormier]

https://www.ezsbc.com/product/wifi01-sw/

Not affiliated but I found this board that has a High Voltage input and a buck converter built in, so you can power this from the 24V (30V) provided by the desk.

[fellwell5]

Hello @ all!

I managed to get my Megadesk running with an ESP8266 and connected it to my Homeassisant.
I wrote it up on a medium post so that other people can follow my steps:
https://medium.com/@matthiasschaffer/make-your-ikea-standing-desk-smart-62b8307da8b6

Also here is direct link to a case a friend of mine made for me, which fits a StepDown Converter or either an ESP8266 or an ESP32:
https://www.thingiverse.com/thing:5438136

Have a great day!

[gcormier]

Very awesome! Glad the servo splitter worked!

[AnAnalogGuy]

Nice work @fellwell5 .

Regarding:

https://medium.com/@matthiasschaffer/make-your-ikea-standing-desk-smart-62b8307da8b6

Do I get it right and that's not needed any more with new orders of Megadesk as it now comes with the serial option enabled (if so, it might be helpful to update the medium article, so ppl know they don't need to flash the AT and therefor also don't need to by the related parts)? Or are there any other/additonal reasons to flash it?

[gcormier]

Correct, the serial firmware is now flashed by default since December 2022.

[Krasnov777]

I also received my Megadesk v.8 with serial enabled feature and decided to use Wemos D1 mini as a microcontroller. I used this instruction for connecting and uploading configuration to the D1.

Because this configuration just runs web server on the microcontroller, I realised that it's good idea to control the desk with HTTP POST method, and as a platform I used Apple Shortcuts and Telegram bot. Here few screenshots how I configured Apple Shortcuts:

And in the recent version of MacOS it's possible to add this shortcuts directly to your dock, so it's really great way to control your desk:

[Krasnov777]

No, I'm just used this configuration, which runs web server on your ESPHome controller.

On this web page you can press the buttons which mapped with the megadesk memory positions. So I just figured which POST URL used when you press those buttons and send it directly from Apple Shortcuts.

For instance, I saved in Megadesk memory positions for button 2 and 3 (for standing and sitting):

And here is how POST URL's looks like

1. http://YOURESPHOMEIP/button/desk_position_2/press
2. http://YOURESPHOMEIP/button/desk_position_3/press

[AnAnalogGuy]

Thanks a lot for clarifcation @Krasnov777.

[osb99]

Please can you send me this shortcut?

[Krasnov777]

@osb99 Please use this shortcut as a reference. You will need to change the IP and button_id.

https://www.icloud.com/shortcuts/10e0c8dc35784018bdd026f52f0f9eea

[osb99]

@Krasnov777 that's great, thanks!

[AnAnalogGuy]

Quick summary guide for those who want to run the ESP controlled megadesk (on Windows):

1. Get a megadesk from Greg's Tindie store: https://www.tindie.com/products/gcormier/megadesk/
2. Follow Greg's installation instructions: https://www.youtube.com/watch?v=jCPlM2KYwDQ.
3. Get the ESP parts, mainly "D1 Mini ESP8266 WLAN Microcontroller" and a "LM2596S DC" (stepdown) converter. Any other ESP controller would work too, but this one has an USB interface, so you don't need a programmer, just a Micro-USB cable, that's it.
4. An enclosure and some wires are needed too, check out Matthias' guide: https://medium.com/@matthiasschaffer/make-your-ikea-standing-desk-smart-62b8307da8b6
5. Get megadesk.h and esphome.yaml from the repository.
6. In esphome.yaml replace the ssid and the password with the correct values from your WLAN router. Both values need to be enclosed with "". If you use " within your password, you have to escape it with \". Value for the board parameter needs to be "d1_mini" without quotes.
7. Download https://cdn.sparkfun.com/assets/learn_tutorials/5/9/7/Windows-CH340-Driver.zip and install it - it's an USB driver needed for Windows to communicate with the ESP board.
8. Connect the ESP board to your PC via a Micro-USB cable.
9. Get Python and install it: https://www.python.org/downloads/windows/. Add Python to the PATH variable of your Windows Computer.
10. Open a windows cmd shell to install ESPHome in your Python (runtime) environment. Run
    pip3 install wheel
    pip3 install esphome
11. From the cmd compile and install the ESPHome package on your ESP microcontroller:
    esphome run megadesk.yaml
12. At the end of the installation (once it is complete), you can find the MAC address of the ESP microcontroller. Add it to your DHCP server and link it to an IP address (xxx.xxx.xxx.xxx).
    Alternative: You could also set a fixed IP address in the yaml configuration.
13. Once done, restart your ESP microcontroller and point a browser to http://xxx.xxx.xxx.xxx to get access to the control interface

Notes:

• I left out the wiring between the ESP controller and Megadesk, as Matthias has described it in detail on his medium article: https://medium.com/@matthiasschaffer/make-your-ikea-standing-desk-smart-62b8307da8b6
• I will add some more information on how to smoothly integrate with windows (clickable icons in the task bar just as @Krasnov777 did for Mac) and maybe with keyboard shortcuts. Have to figure out a solution first, will share.
• I'm also thinking about a little Mobile App to control the desk, maybe also adding a timer function to remind users to change position after a while. Again, I have to figure out a solution first, will share, might take a while.

Keep in mind:

• ESPHome does not offer HTTPs support (reason: limited cpu power). This means, communication between the client app and the ESP board is unencrypted.
• You could add a username/password protection to the webserver to add a certain level of protection, however, as basicauth is used, passwords are not encrypted and transported over non-secure http.
• So bottom line: Consider your megadesk to be publicly acccessible, at least within your LAN.

web_server:
port: 80
auth:
username: admin
password: !secret web_server_password

[gcormier]

Sure, I made #127 and will put some files up this week. Thanks for the step-by-step!

[calvinbui]

I tried connecting a knock-off D1 Mini to the Megadesk today but to no avail. Can anyone notice what I've done wrong? I purchased it in February, so it should've arrived with a serial enabled firmware.

I definitely wired it up correctly with a JST wire.

MISO -> RX (Yellow)
SCK -> TX (Red)
GND -> GND (Black)

D1 Mini Rear

D1 Mini Front

Megadesk Front

Megadesk Rear

JST

ESPHome

[AnAnalogGuy]

There is one GND connection not shown in your picture and that's the one that might make the problem:

https://en.wikipedia.org/wiki/Ground_loop_(electricity)

[calvinbui]

I removed the black cable from the connector and didn't work either. I'll look at grabbing a LM2596S and trying again. They are about $3 AUD from AliExpress.

[AnAnalogGuy]

Yes, removing GND alone won't solve the issue.

Once you have the stepdown convertor, first only connect it to power supply from the Bekant (to the 24V input connectors).

Then switch the power supply on and measure the voltage outpout of the stepdown convertor on the output connectors.

It has a variable and adjustable restistor. While measuring the output voltage, adjust the resistor so you get out 3.3V.
Once done, you can go on connecting the rest according to @fellwell5 layout.

And of course, have the USB cable disconnected all the time to avoid a ground loop.

[AnAnalogGuy]

There is potentially a second issue with the pins you used.
It seems you used the pins labeled TX and RX. But these are not the pins used in the code.

Unless you didn't change the code, you would have to solder SCK on megadesk to D0 on the D1 mini and accordingly MISO to D1

But please, to protect the D1 mini, wait until you got the stepdown convertor to make sure you don't create a problem with GND (as these little boards can get roasted quite easily).

[calvinbui]

I changed the uart code and it worked 👍 😲 🏆

i'll wait for the stepdown converter before connecting it permanently

[AnAnalogGuy]

I think the ground here isn't needed as you have ground already connected trough your red-yellow-black cable.

Best would be you show us a complete picture of your setup with all components and connections.

[AnAnalogGuy]

Regarding GND -> if you are using different GND on your boards (and from what you are describing, you might be) you might run into issues because you might have different electrical potentials on your boards. This might be an explanation for the problem you have.

This is why @fellwell5 solved the power supply with a stepdown transformer connected to the same ground as the megadesk:

From my point of view this would be the better approach than using a seperate USB power supply.
The stepdown convertor used here is a LM2596S.