Work ยท Home energy
12-circuit home energy monitor: 2,300 units shipped
Our client wanted a device that shows a household which circuit is using power right now. We designed the electronics and firmware, and about 2,300 units have shipped.
Result
2,300units shipped under the client's brand- Timeline
- ~12 monthsfrom the first concept sketch to the first manufacturing batch
- Channels
- 12 circuitsmeasured at the same time, each on its own current sensor
- Radios
- 2Wi-Fi for the data, Bluetooth for setup from a phone
The brief
A household meter gives one number for the whole house. The client wanted a per-circuit picture that a homeowner or a small business can read on a phone.
Problem
Homeowners and small businesses want to know which circuit uses the power and when. A single utility meter cannot tell a heat pump from a dryer, and a monthly bill arrives too late to change anything.
Where tariffs change through the day, the same data lets the user shift a load to a cheaper hour.
Constraints
Twelve current channels had to fit one board that lives next to the breaker panel. Readings go to a phone app over Wi-Fi, and a phone has to be able to set the device up over Bluetooth before it is on the network.
The result had to be a product the client could sell, so the board and firmware were designed for a manufacturing batch from the start.
What we built
The 12-channel monitor: electronics, firmware, and the Wi-Fi and Bluetooth link to the app and the cloud. Each circuit has its own live reading and its own threshold; when a circuit crosses it, the user gets an alert on the phone or by email.
The cloud keeps the history and builds daily, weekly and monthly reports for one circuit or the whole house, which the user can export.
How the data gets to the user
A current sensor on each of the 12 circuits feeds the monitor. The monitor measures all 12 live and sends the readings over Wi-Fi to the user's app and to the cloud. The cloud stores the history, builds the reports and watches each circuit's threshold; when a circuit crosses its limit, the alert goes to the phone or to email. Bluetooth is used once, to put the device on the Wi-Fi network from a phone.
What the user sees
The app shows each circuit on its own line, in watts, as it is now. Big loads such as a heat pump, a range or an EV charger stand out from lighting and outlets, so the user can see where the power is going before the bill arrives.
The chart is an example of such a view. The values are illustrative; we do not publish customer data.
The device
The board, its antenna and the current-sensor leads, as shipped to the client.
Unpacked: the board and its Wi-Fi antenna in the box. 
With the external antenna, for Wi-Fi from inside a utility room. 
With the antenna and one clip-on current sensor; each circuit gets one.
What the project used
This was an electronics and firmware project with manufacturing support: the schematic and layout for a 12-channel measurement board, the firmware that samples every circuit and runs the Wi-Fi and Bluetooth radios, and the data link to the client's app and cloud. The board went through several revisions before the first batch.
A device like this moves through the same stages as our other projects, from prototype to a manufacturing batch. For devices that need dashboards and alerts without building a cloud of their own, we run Rainforest IoT.
- Channels
- 12 circuits
- Radios
- Wi-Fi and Bluetooth
- Units
- 2,300 shipped
- Timeline
- About 12 months to first batch
Start your own device
Tell us what the device has to measure, where it will be installed and how many you expect to build. We reply within 24 hours with the next step.
Other projects: the solar roof camera and the ESP32 Tuya gateway.
Common questions
How long did the energy monitor take to develop?
About 12 months from the first concept to the first manufacturing batch, including several board revisions.
How many units were made?
About 2,300 units have shipped so far.
How many circuits does it measure?
Twelve circuits at the same time, each with its own current sensor and its own live reading in the app.
How does the data reach the user?
The monitor sends readings over Wi-Fi to the user's phone app and to the cloud, which keeps the history and builds daily, weekly and monthly reports. Bluetooth is used for the first setup from a phone.
Can I buy this energy monitor?
No. It is our client's product and they sell it under their own brand. We can design a monitor for your brand; tell us what it has to measure.
Can you build a similar monitor for our company?
Yes. The same path applies: electronics and firmware, the app data link, a batch with a contract manufacturer. See how we work and the three other devices on the work page.
What does a project like this cost?
It depends on the channel count, the enclosure, certification and the batch size. We quote the first stage after a 30-minute call.