Guy's Tesla Panel Build

The ugliest page on the net

UPDATES

3 March 2021: Rather big update:

1. Updated all the code to use JSON rather than manually finding text in the return value from the Gateway

2. Updated the code to display local tempature on Strip 6 rather than Grid Voltage.  There is a variable Display6 in the script you can set to Temp or Volt to display Temperature or Voltage.

3. All diplays default to off pixels for those not having data now.  To turn back to the light blue as in the photos, change the RGB values from (0, 0, 0) to (0, 1, 1)

9 Feb 2021 9:30PM : Sweet!  New code released below in the link to the ZIP file which now logs into your Tesla Gateway to get the data required.  You will need to edit the script to add your LOCAL Customer Login email and password to the script.  To find out how to set up this local login account (if you hanv't already) follow the instructions on Telsa's page HERE.

9 Feb 2021 : eeek!  Tesla just updated my Gateway 2 and my code has stopped working as it now needs to login to the Gateway before gettng the data for display.
I am looking into how to address this however it may take some time.

1 Feb 2021:  Origonal page posted

Not yet finished, but getting there.
Currently, from left to right:
1: Battery Charge % (red when charging, green when 100%)
2: Solar generation (scaled to my max 10kW
3: Feed in kW to Grid (green for feed in, deep blue for draw)
4: Current house load (scaled to 10kw currently).

Next steps:
-Print some logos for the bottom (maybe an excuse to buy one of those laser engravers 🙂
-Work out a good 5v power solution (currently running off a lab power supply. I think I have an idea for this.

Intro

So you found my little page.  1st thing to note is I am no web designer so yes, I know this page is not fancy, it is plain, but hopefully it is also 'functional'.  I am also sure there are many spelling mistakes and typos in this page!
I started this little project as I have a Tesla Powerwall 2 with associated Gateway 2 and I have found that I am always looking for a quick way to see what is happening with not only the status of the battery, but also the PV panels, household power usage, feed in or draw from the grid etc.

The Tesla app gives you a pretty nice way of seeing all that, but I have to open the app on my phone, its not exactly there at a glance.

I have set up an old Microsoft Surface 2 table/laptop to display the Gateway's local interface however from a distance its not easy to see the values, and because the Gateway uses a self signed certificate every now and then I need to re-accept the certificate for the page to display.  I probably could find a way around this, perhaps installing the cert on the laptop would do it, but the display is still too small.

Therefore I embarked on a little project to create an analogue display to present the data.  Analogue is always best for a quick glance of a value, when accuracy isn't overly critical.

What you need to copy this

• A Raspberry Pi. I believe almost any Pi with a network connection could work for this however I have only tested with a Pi Zero and a Pi 4b.
• Programmable Light Strips:  I am using the WS2812B light strips however you should be able to use any strip that works with the 'neopixel' Python library as long as you can adjust my steps for the differences in your strip of choice.  The ones I got are actually 2 50xm strips soldered together in the middle which made separating the strip into 2 really easy!  All I had to do was add a wire to reconnect the signal line, and inject power into the second half as well.  You can add more and more strips this way as well.  I am sure there is a limit but I am not sure what the limit it.  See below for how the strip is 'broken' in two.

• A power supply for both the Pi and the light strip.  Note:  The Pi will not be able to power the strip itself.  Note:  I am successfully powering 6x 72 Pixel strips and a Raspberri Pi Zero using only a 2.5A USB Adaptor.  I can do this as my pixel brightness values are VERY low (the lowest possible for the strip in most cases).
• This ZIP file (Version 1.2 3 Mar 2021) which has the Python Script tesla.py.  Note:  I am a hack and slash programmer, as in I know I am cutting many corners, not following 'standards' etc.  Deal with it, I have barely programmed in Python and am just getting this out there for those who want to see the general approach I took to get this up and running.  You can modify the code as much as you like as long as you don't try to sell it or make a profit out of it.  I am giving it to you for free as well after all.

Getting it working

Step 1:  Set up your Raspberry Pi in the standard way.  This is not part of this 'instruction set'.  You just need Raspbian installed and the ability to access either a SHELL or VNC connection.  VNC is easier for novices as it also lets you copy files from your computer to the Pi.

Step 2: Open a shell and run the command sudo pip3 install rpi_ws281x adafruit-circuitpython-neopixel

Note: This command is also in the text file you downloaded in the file "Setup For Light Strip.txt"

Step 3: Copy the file tesla.py from the ZIP file to your Raspberry Pi.

You can close this window now

Step 4: Move the file into your home folder.  If you open the Folder browser it will default to your home folder.  Just put the file in there.  You really can put it anywhere you like however this is the folder a shell window opens in to it makes it easier to run if it is already in this folder

Before you run the code you have two tasks to complete.

1. Connect your Light Strip/s to the Raspberry Pi

2. Modify the code for YOUR light strip setup

Connect your Light Strip/s to the Raspberry Pi

• Your light strip should be connected as one long string.  This way we only need one signal line and just divide the strip up in the code for different display segments.

• You will need to inject power into your strip from a separate power source as the Pi will not be able to power the strip itself.

• My strip was 5v.  As the Pi is also powered from 5v I was able to power both the strip and Pi from the same power supply.  You can just use the USB port to power the Pi.  Make sure the strip and Pi share a common ground.  Connect the ground to the Pi on Pin 06.  More info on powering your Pi here.

• The default code runs the LEDs at almost their lowest brightness.  Each 72 pixel strip consumed about 150mA at these low settings.

• Connect the SIGNAL of the Strip to PIN12 (GPIO18) of the Pi.  This is the default pin for the nanopixel library.  See here for which pin is which on the Pi.

Modify the code for YOUR light strip/s.

• Open tesla.py with a text editor or Thonny IDE on the Pi itself

• Find the section marked Constants

• You will need to modify the above values for your system.
• Part 1: Modify the password and email address for your Gateway 3 Customer Login in this section just under :Constants
            
• Part 2: For example if you bought a single meter of strip with 60 pixels per meter and you want 2 50cm displays (after breaking the strip in half) you would set:
  • NoOfPixels = 60
  • NoOfDisplays = 2
• Part 3: The Code Start****Pixel calculations to determine where a value is displayed from. It does NOT dynamically adjust for this changing.  If you do not have 4 displays like my example you will need to:
  • Change the value of the Start Pixel for what you want to display
    • First Start value is just = 0
    • Second Start Value is the value with no number multiplying the line
    • Third Value has a leading 2*
    • Fourth Value has a lading 3*
    • So on and so forth.
    • Note above I have both StartBattLoadPixel and StartGridPixel both at 2*.  That is because I am not using StartBattLoadPixel yet.  When I use it, I will have to change it.
  • Comment out any section in the code below that that tries to write to the light strip that you don't actually have (add a leading #).
    • e.g.:  If you do not want to display Home Load change the code as below:

BEFORE

AFTER

• Part 4:  You will need to create an account and get an API key from openweathermap.org if you want to be able to display your local weather temperature on a strip.

• If you want to slow up the refresh interval, find the line below and change the 1 to how many seconds you want to pause between updates

• If you do not want to output to the console any of the values, find the lines that start with printf and comment them out with a #

Running the Code

• To run the code, simply open a terminal windows type "sudo python3 tesla.py" and then press enter!
• If you put the code in another folder you will need to adjust the command above accordingly.

I hope that is enough to get you going.  How you mount it is up to you, I might add some information later on how I did it if I have time.

Troubleshooting (no display on strip?)

• Try just using one segment of strip (before you even break it in two if you like), comment out all the code for anything but displaying the battery charge % and get that running.  Then expand your display for more sections knowing the basics are working.
• Check there are no short circuits
• Check each strip in your display is getting a good 5v
• Ensure your power supply is up to the job
• Reboot your Pi, make sure the power strip has power connected before you reboot the Pi
• Turn everything completely off, power the strip, then start the Pi.
• Make sure you are not trying to write to parts of a display that does not exist in your setup!

Cheers

Guy Barwood