Arduino Power Meter Modbus Client

Acts as a Modbus master device to collect data from a slave Power Meter device. Readings are taken every second and then output in YAML format.

Hardware Interface

MAX485 with the following pin connections:

MAX485	Arduino Micro	Espressif ESP8266
VCC	+5V	N/A¹
GND	⏚ (GND)	GND
DI	0 (TX)	1 (U0TXD)²
RO	1 (RX)	3 (U0RXD)²
DE	4	GPIO4²
R̅E̅	5	GPIO5²

¹ a separate +5V supply is required

² via a 3.3V to 5V logic level converter

Arduino Micro

Output is on the USB serial console.

Espressif ESP8266

Output is on the UART1 TX GPIO2 pin at 115200 8N1.

To configure the WiFi SSID and passphrase, connect GPIO14 to GND and the device will enter AP mode using the SSID 🔌 ########.

Supported Power Meters

• Rayleigh Instruments RI-D19-80-C: 230V 5/80A LCD Single Phase Energy modbus – 80A Direct With RS485 Output

Sample Output

meter: {model: "RI-D19-80-C",serialNumber: "############",reading: {voltage: 2471.0e-1,current: 3.0e-1,frequency: 500.0e-1,activePower: 81.0,reactivePower: 28.0,apparentPower: 90.0,powerFactor: 1000.0e-1,temperature: 31.0,activeEnergy: 88.0e-2}}

2017-03-11 13:57:53 INFO serialNumber=############, voltage=247.1 V, current=0.3 A, frequency=50.0 Hz, activePower=81 W, reactivePower=28 var, apparentPower=90 VA, powerFactor=100.0 %, temperature=31 °C, activeEnergy=000000.88 kW·h