energy-monitor

“You can't improve what you don't measure”

This project is a DIY module + a Rust application that aims at measuring grid consumption metrics, display collected values on an OLED display, and send them to an external InfluxDB database for storage.

The module was designed to fit any European-standard distribution boards (same form factor as a circuit breaker) and has 90mm (5-module) width. It does not collect data directly but rather fetches metrics from Lechacal's RPICT module and Enedis Linky electric meter (France national power provider).

I built this project to observe and store my own energy consumption, to eventually improve it. And, well... also because it looked a cool DIY project (it actually was!).

⚠️ My electrical installation has three-phase power supply. Even though the project could run on one-phase power supply, it might also need some adaptation. Any contribution welcome!

Table of contents

Application
Hardware
- Parts
- Wiring
- Enclosure
Photo gallery

Application

This project includes a Rust application that handles everything, from I/O to display.

Interface

The user interface is composed of several pages that can be cycled using the push button (like a carousel).

Startup screen

This screen displays the project logo, connection statuses and the current application version. It is shown at application startup and also belongs to the page carousel (last position).

Connection statuses are:

RPICT status, white square means connected.
Linky status, white square means connected.
InfluxDB status, white square means connected.

Instantaneous metrics screen (RPICT)

This screen displays instantaneous metrics measured from the RPICT:

lines apparent power value with a gauge that shows the max seen value since boot
sum of consumed lines power
mean of lines RMS voltage

It is the first displayed screen when waking up from sleep.

Cumulated metrics screens (Linky)

This screen displays instantaneous metrics collected from the Linky:

Linky's counter unique id
"heures creuses" and "heures pleines" indices, used for billing

Installation

To run the energy-monitor application on a Raspberry Pi Zero W:

install a fresh Raspberry Pi OS on a SD card
insert the SD card and open a terminal (desktop or ssh)
configure the system to enable SPI and UART via the raspi-config helper
ensure user pi belongs to group spi, gpio and dialout using command usermod -aG spi,gpio,dialout pi
download energy-monitor binary from the Github Release section
run the application with the energy-monitor binary. You can override configuration using YAML config file or environment variables. See Configuration section below for a full list of overridable settings.

$ energy-monitor -h
A tool to measure, display and store electrical consumption metrics.

Usage: energy-monitor [OPTIONS]

Options:
  -c, --config <FILE>  Sets a custom YAML config file
  -h, --help           Print help
  -V, --version        Print version

For advanced users:

use a systemd service to launch the application at system startup

Configuration

You can configure the application either by providing a YAML config file (see -c --config <FILE> binary arg) or using environment variables:

YAML path	Environment variable	Description	Default
`log_level`	`APP__LOG_LEVEL`	Application log level	`INFO`
`hmi.sleep_timeout_secs`	`APP__HMI__SLEEP_TIMEOUT_SECS`	Duration in seconds before shutting down display	`30`
`hmi.max_line_power_watts`	`APP__HMI__MAX_LINE_POWER_WATTS`	Max expected line power in watts	`6900`
`hmi.button_debounce_ms`	`APP__HMI__BUTTON_DEBOUNCE_MS`	Push button debounce duration in milliseconds	`100`
`hmi.button_bcm_pin`	`APP__HMI__BUTTON_BCM_PIN`	Push button BCM pin number	`27`
`serial.rpict`	`APP__SERIAL__RPICT`	Serial port for RPICT	`/dev/ttyAMA0`
`serial.linky`	`APP__SERIAL__LINKY`	Serial port for uTeleinfo (Linky)	`/dev/ttyUSB0`
`influxdb.host`	`APP__INFLUXDB__HOST`	InfluxDB host	`localhost`
`influxdb.port`	`APP__INFLUXDB__PORT`	InfluxDB port	`8086`
`influxdb.database`	`APP__INFLUXDB__DATABASE`	InfluxDB database	`metrology`
`influxdb.prefix`	`APP__INFLUXDB__PREFIX`	Application's measures prefix	`energy`

Hardware

The module is composed of several parts listed in the Parts section. Electronics parts (push button, OLED display and RPICT) are wired to the Raspberry Pi, see Wiring section. RPICT is tied to the Raspberry Pi module via 29.7mm Brass Standoffs, they are both tied to enclosure's part 1 via clips. The OLED display is tied to enclosure's part 3 the same way.

Parts

The following table presents the partlist needed to build a full module:

Part	Quantity	Price	Links
Raspberry Pi Zero WH	1	14.60€	buy
5V 3A Micro USB Power Supply	1	2.30€	buy
Sandisk Micro SD card 16GB Class 10	1	9.90€	buy
Waveshare 2.23" OLED Display 128×32 Pixels SPI/I2C	1	23.00€	buy / doc
LeChacal RPIZ CT3V1	1	18.30€	buy / doc
LeChacal EU AC/AC Adaptor	1	15.00€	buy
3pcs SCT-013-000 Current Transformer	1	11.30€	buy
3pcs 6x6x4.3MM 4PIN G89 Push Button	1	0.70€	buy
200pcs M2.5 Brass Standoffs	1	9.90€	buy
(optional) Charles Micro Teleinfo V2.0	1	22.90€	buy / doc
(optional) 3pcs Micro USB to USB 2.0 adapter	1	5.00€	buy

Total price is roughly 130€, not counting shipping.

Wiring

The following tables uses the following Raspberry Pi pinout as reference:

In order to achieve wiring between parts, you may need the following tools/parts:

Part	Price	Link
22AWG Electrical Wire box	11.80€	buy
620pcs Dupont Connector kit 1	4.00€	buy
310pcs Dupont Connector kit 1	4.00€	buy
SN-28B Pin Crimping Tool	4.00€	buy

RPICT

RPICT	Raspberry Pi	Physical
1	3.3	1
6	GND	6
8	GPIO14 (UART0_TXD)	8
10	GPIO15 (UART0_RXD)	10

OLED display

OLED	Raspberry Pi	Physical	BCM
VCC	3.3	17	-
GND	GND	20	-
DIN	MOSI	19	10
CLK	SCLK	23	11
CS	CE0	24	8
D/C	GPIO5	18	24
RES	GPIO6	22	25

Push button

Push Button	Raspberry Pi	Physical	BCM
1	GPIO27	13	27
4	GND	14	-

Enclosure

The enclosure contains 3 clippable parts so that it is easier and faster to print on a 3D printer. Assembly only needs a bit of epoxy to hold the push button in place. Don't forget to place the 3D-printed button before glueing the push button! The enclosure was designed using Autodesk Fusion 360.

You can find emonitor-part*.stl STL files in the project's enclosure directory.

I printed mine in 6 hours, using PrusaSlicer as slicer, and with the following parameters:

0.20mm SPEED profile
20% infill
support on build plate only
white 1.75mm PLA filament

Notes:

don't forget to print the button in your favorite color, see button.stl STL file
I also designed an enclosure for utinfo, see uteleinfo-part*.stl STL files