A pint of demand

I recently switched to Octopus Energy and got one of their Home Mini devices, which connects to my electricity meter via ZigBee and to my home Wi-Fi to upload meter data to the Octopus servers every 10 seconds. Using their GraphQL web API, you can check your current electricity demand anytime. I've documented how to use their API to get your current electricity demand here. Much more is possible from their API but I only need the current electricity demand.

Here is a fun project to visualise your electricity demand data with a strip of 50 colour LEDs. The colour varies, purple to red, with your current electricity demand.

I'm using a Pimoroni Plasma 2350W which is a USB-C powered controller for WS2812/Neopixel addressable LED strips with 2.4GHz Wi-Fi. The Raspberry 2350W is running MicroPython v1.27. I also have a 5m Flexible RGB LED Wire (50 lights). You could use a standard Raspberry Pico 2W but the Pimoroni version has the advantage of a set of screw terminals for easily connecting the LED strip.

The MicroPython code requests your current electricity demand data from the Octopus server every 30 seconds, which, with the limit of 125 requests per hour, is about as fast as possible.

You'll need to install the latest Pimoroni MicroPython code (plasma_2350_w-v1.1.0-micropython.uf2) from here. You probably don't want the "with-filesystem" version as that one replaces any files already stored on the 2350W's file system with some demo files.

There are four files in this project. You can download them in a .zip file from here.

main.py which automatically launches OctopusElec.py when turned on

OctopusElec.py which is the main code

graphqlclient.py which makes the GraphQL requests and 

secrets.py shown below where you must enter four bits of your information.

WIFI_SSID = "Your WiFi SSID"

WIFI_PASSWORD = "Your WiFi Password"

OCTOPUS_ACCOUNT = "Your Octopus Account number in A-abcdabcd format"

OCTOPUS_APIKEY = "Your Octopus API Key"

To get the API Key click the "Generate my API key" on this Octopus page (you'll need to be logged into your Octopus account).

The easiest way of getting the code onto the Plasma 2350W is to connect it to your PC with USB and to use Thonny to copy the files onto the device. After you've modified the secrets.py file you can disconnect from the PC and power it up from any USB power socket.

Here are the steps:-

1) Buy a Pimoroni Plasma 2350W and 50 LED wire

2) With a USB lead plugged into your PC power up the 2350W with the boot button pressed, it will appear as a new drive. Copy the latest firmware, plasma_2350_w-v1.1.0-micropython.uf2, onto the drive

3) Download and unzip the .zip file containing the project .py files from here

4) Edit the secrets.py file with your Wi-Fi SSID, password, Octopus account number and Octopus API key

5) Use Thonny to copy the four files (main.py, OctopusElec.py, secrets.py and graphqlclient.py) onto the 2350W

6) Press the reset button on the 2350W and it should connect to Octopus servers and start displaying your electricity demand as a colour. Logging is displayed whilst the 2350W is connected to your PC.

Near the top of OctopusElec.py there are some settings you can alter.

# ─── Configuration ────────────────────────────────────────────────────────────

LOW_W       = 100   # The lowest wattage expected (violet)

HIGH_W      = 6000  # the highest wattage (red)

REFRESH_MS  = 30000 # How often the consumption is requested. Not too fast or API will rate limit

NUM_LEDS    = 50    # The number of LEDs on the strip

ONBOARD_DIM = 0.15  # onboard LED default brightness (0‑1)

Change LOW_W and HIGH_W to set the typical demand range in your house. This might take a bit of trial and error.

Don't alter the REFRESH_MS below 30000 (30 seconds) as anything more frequent causes the API to fail with request limit exceeded errors.

If you'd like to switch to Octopus you can use my referral code for a £50 discount https://share.octopus.energy/playful-engine-680

Get real-time electricity consumption from Octopus Home Mini

I recently switched to an Octopus energy account as they provide a device to allow you to access your real-time electricity consumption from your smart meter. On request Octopus will provide a free Home Mini device which connects to your smart meter with ZigBee and to your home Wi-Fi to upload your electricity consumption every 10 seconds.

If you'd like to switch to Octopus you can use my referral code for a £50 discount https://share.octopus.energy/playful-engine-680

To access the real-time data you query the Octopus API using GraphQL format HTTPS Posts.

To start you need the following: your Octopus account number (A-AAAA1111 format) and your Octopus API Key which you can create here. The API key is like a password so don't reveal it to anyone. If necessary, you can regenerate the key using the same link.

There are 3 steps:

Step 1

Get a Kraken bearer token using the following query. The token lasts for 1 hour before a new, or refreshed, one is required.

URL	https://api.octopus.energy/v1/graphql/
Query	mutation ObtainKrakenToken {     obtainKrakenToken(input: { APIKey: "sk_live_Your developer API key" }) {         token         payload         refreshToken         refreshExpiresIn     } }
Authentication	None

The result will be as shown below. You only need the text of the long token string.

{

    "data": {

        "obtainKrakenToken": {

            "token": "eyJhbGciOiJSUzI1NiIsImlzcyI6Imh0dHBzOi8vYXBpLm9jdG9wdXMuZW5lcmd5L3YxL2dyYXBocWwvIiwiamt1IjoiaHR0cHM6Ly9hdXRoLm9jdG9wdXMuZW5lcmd5Ly53ZWxsLWtub3duL2p3a3MuanNvbiIsImtpZCI6InFRb3hIbzhiTF91Wi1NdE9kQ2labDZacjFaMWsyM1l2Y0taZnU5QldHNkEiLCJ0eXAiOiJKV1QifQ.eyJzdWIiOiJrcmFrZW58YWNjb3VudC11c2VyOjEzMjMyODc3IiwiZ3R5IjoiQVBJLUtFWSIsImVtYWlsIjoiYW5kcmV3LmpvbmVzQGFscXVpc3QuY28udWsiLCJ0b2tlblVzZSI6ImFjY09090909sd09sd09s0d9pLm9jdG9wdXMuZW5lcmd5L3YxL2dyYXBocWwvIiwiaWF0IjoxNzc4ODczMjA1LCJleHAiOjE3Nzg4NzY4MDUsIm9yaWdJYXQiOjE3Nzg4NzMyMDV9.ABJbgP0gvh68SqNx-GGXGVq4_WSbZ6vqfWb9veWYV0mHojyMkW-EqMUMhVrtvIFYhyom4qbWodfnAGrNIh0akpauzCJG-6qFa8Noynuibqlu4RmoVThYbIOUGbqO6p-VQmKPACKuhimfCzntU2m_Gh2uNr8Tbsx5pqXPnGp6S10LQm1eJvrKmJ4ca1PDh53lx75zgDo-JjARKXm4M4JHbjN5D4TlfJ7fPGlrZktafYad9XwvN1DraAutB4Ur-8ogCpVo7IoBWnnN7gaJCFSEALfi03_wb6ydx-Kb0qnbpKyi-DkJYCn-8EFowQEfA2SKgHMz8nPAN0e58Cb385bS1Q",

            "payload": {

                "sub": "kraken|account-user:000000",

                "gty": "API-KEY",

                "email": "andrew@000000",

                "tokenUse": "access",

                "iss": "https://api.octopus.energy/v1/graphql/",

                "iat": 1778873205,

                "exp": 1778876805,

                "origIat": 1778873205

            },

            "refreshToken": "faff3b0d2700cc9cd6c2fc8d000000e31466dd0daea2149d4c2c68f1",

            "refreshExpiresIn": 1779478005

        }

    }

}

Step 2

You need to establish the deviceId for your electricity meter. Using your Account Number and the bearer token from step 1. I think you only need to do this once as I don't think the deviceId changes.

URL	https://api.octopus.energy/v1/graphql/
Query	query MyQuery {     account(accountNumber: "A-YourAccountNumber") {         electricityAgreements(active: true) {             meterPoint {                 meters(includeInactive: false) {                     smartDevices {                         deviceId                     }                 }             }         }     } }
Authentication	The bearer token from the step 1 above

The result will be as below, you'll need your deviceId for step 3.

{

    "data": {

        "account": {

            "electricityAgreements": [

                {

                    "meterPoint": {

                        "meters": [

                            {

                                "smartDevices": [

                                    {

                                        "deviceId": "00-00-00-00-00-00-00-00"

                                    }

                                ]

                            }

                        ]

                    }

                }

            ]

        }

    }

}

Step 3

To read the real-time electricity consumption you need the bearer token from step 1 and the 8 byte deviceID from step 2

URL	https://api.octopus.energy/v1/graphql/
Query	query SmartMeterTelemetry {     smartMeterTelemetry(deviceId: "Your deviceId from step 2") {         readAt         consumption         demand     } }
Authentication	The bearer token from step 1

Your current consumption, in Watts, is in the demand field shown below. I've been making this request every 30 seconds and the API seems happy with that.

{

    "data": {

        "smartMeterTelemetry": [

            {

                "readAt": "2026-05-15T17:14:50+00:00",

                "consumption": "55667150",

                "demand": "700"

            }

        ]

    }

}