meta data for this page
  •  

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

sensor:ina219 [2026/02/13 15:19] – created - external edit 127.0.0.1sensor:ina219 [2026/02/13 15:58] (current) – [I²C topics on lamaPLC] vamsan
Line 1: Line 1:
-====== LamaPLC: CJMCU-219/INA-219 breakout board/IC with I2C communication  ====== +====== LamaPLC: CJMCU-219/INA-219 breakout board/IC with I²C communication  ====== 
-The CJMCU-219 is a breakout board featuring the INA219 IC, a zero-drift, bidirectional current and power monitor with an I2C interface.+{{ :sensor:ina219.png?180|CJMCU-219/INA-219 breakout board/IC with I²C communication}} 
 +The **CJMCU-219** is a //breakout board// featuring the **INA219** //IC//, a zero-drift, bidirectional current and power monitor with an [[com:basic_i2c|I²C]] interface.
  
-Core Technical Specifications+**Core Technical Specifications**
  
-Voltage Measurement: Can detect bus voltages from 0V to +26V DC. +  * **Voltage Measurement:** Can detect bus voltages from **0V to +26V DC**. 
-Current Range: Measures up to ±3.2A bidirectionally using its built-in 0.1 ohm shunt resistor. +  * **Current Range:** Measures **up to ±3.2A** bidirectionally using its built-in 0.1 ohm shunt resistor. 
-Supply Voltage: Operates on +3.0V to +5.5V. +  * **Supply Voltage:** Operates on **+3.0V to +5.5V**. 
-Precision: Features a 12-bit ADC with a maximum error accuracy of 1% over -40°C to +85°C. +  * **Precision:** Features a 12-bit ADC with a maximum error accuracy of 1% over -40°C to +85°C. 
-Interface: Uses I2C communication (standard 100kHz or high-speed 400kHz/3.4MHz) with a default address of 0x40. +  * **Interface:** Uses I²C communication (standard 100kHz or high-speed 400kHz/3.4MHz) with a default address of **0x40**. 
  
-Key Features+**Key Features**
  
-High-Side Sensing: Unlike many sensors, it can measure current on the high side (between the power source and the load), which prevents ground reference issues. +  * **High-Side Sensing:** Unlike many sensors, it can measure current on the high side (between the power source and the load), thereby avoiding ground-reference issues. 
-Multi-Function Reporting: It calculates and reports bus voltage, shunt voltage drop, current, and total power (W) directly. +  * **Multi-Function Reporting:** It calculates and reports bus voltage, shunt voltage drop, current, and total power (W) directly. 
-Programmability: Supports software-programmable calibration, filtering (averaging up to 128 samples), and conversion times. +  * **Programmability:** Supports software-programmable calibration, filtering (averaging up to 128 samples), and conversion times. 
-Daisy-Chaining: Supports up to 16 programmable I2C addresses, allowing multiple modules to run on the same bus. +  * **Daisy-Chaining:** Supports up to 16 programmable I²C addresses, allowing multiple modules to run on the same bus. 
  
-Safety & Limitations+**Safety & Limitations**
  
-Voltage Limit: The chip may be damaged if bus voltage exceeds its absolute hardware limit of 26V. +  * **Voltage Limit:** The chip may be damaged if bus voltage exceeds its absolute hardware limit of 26V. 
-Inductive Loads: Users should be cautious with large motors, as "flyback" voltage spikes can exceed the 26V threshold and destroy the sensor. +  * **Inductive Loads:** Users should be cautious with large motors, as //"flyback"// voltage spikes can exceed the 26V threshold and destroy the sensor. 
  
-===== Arduino =====+====== CJMCU-219 Pinout ====== 
 +{{ :sensor:ina219_1.png?400|CJMCU-219 Pinout}} 
 +**Logic and Power Pins** 
 + 
 +These pins connect to your microcontroller (e.g., Arduino or Raspberry Pi) to power the sensor and transmit data.  
 + 
 +  * **VCC:** Supply voltage for the module (**3.0V to 5.5V**). 
 +  * **GND:** Common ground for both power and logic. 
 +  * **SCL:** I²C serial clock line. 
 +  * **SDA:** I²C serial data line. 
 +  
 +**Measurement (Load) Pins** 
 + 
 +These pins are placed in series with the positive side (high-side) of the circuit you want to monitor.  
 + 
 +  * **Vin+:** Connect to the positive terminal of your power source (e.g., battery). 
 +  * **Vin-:** Connect to the positive terminal of your load (the device being powered).  
 + 
 +**I²C addressing Pins (A0 & A1)** 
 + 
 +Some versions of the CJMCU-219 include solder pads labeled **A0** and **A1**. By default, these are connected to GND, setting the I2C address to **0x40**.  
 + 
 +Bridging these pads to VCC allows you to set the address to any of 16 values (**0x4F**), enabling multiple sensors on the same I²C bus.  
 + 
 +<color red>Caution: The maximum bus voltage the Vin pins can safely handle is 26V DC.</color>
 ==== Arduino wiring ==== ==== Arduino wiring ====
-  * SCL: A5 +  * VCC → Arduino 5V (o 3.3V). 
-  * GND: GND +  * GND → Arduino GND. 
-  * SDA: A4 +  * SCL → Arduino SCL (A5 on Uno/Nano). 
-  * Vdd: 5V+  * SDA → Arduino SDA (A4 on Uno/Nano). 
 +  * Vin+ → Positive side of your power supply. 
 +  * Vin- → Positive side of your load (the device being powered).  
 ==== Arduino code ==== ==== Arduino code ====
 +To begin using the CJMCU-219 with Arduino, the easiest approach is to use the **Adafruit INA219** library.
  
 +This example code sets up the sensor and outputs voltage, current, and power readings to the Serial Monitor at **115200 baud**.
 +
 +A simple example with the Adafruit_INA219 library involves initializing the sensor and repeatedly reading and displaying bus voltage, shunt voltage, load voltage, current, and power. The complete code is available in the provided source document.
 <code c> <code c>
-sample+#include <Wire.h> 
 +#include <Adafruit_INA219.h> 
 + 
 +Adafruit_INA219 ina219; 
 + 
 +void setup(void) { 
 +  Serial.begin(115200); 
 +  while (!Serial) { delay(1); } // Wait for serial port to connect 
 + 
 +  // Initialize the INA219 (default address 0x40) 
 +  if (!ina219.begin()) { 
 +    Serial.println("Failed to find INA219 chip"); 
 +    while (1) { delay(10); } 
 +  } 
 + 
 +  // Optional: Set calibration for higher precision 
 +  // Default is 32V, 2A. Alternatives: 
 +  // ina219.setCalibration_32V_1A(); 
 +  // ina219.setCalibration_16V_400mA(); 
 + 
 +  Serial.println("Measuring voltage and current with INA219..."); 
 +} 
 + 
 +void loop(void) { 
 +  float shuntvoltage = 0; 
 +  float busvoltage = 0; 
 +  float current_mA = 0; 
 +  float loadvoltage = 0; 
 +  float power_mW = 0; 
 + 
 +  // Read data from sensor 
 +  shuntvoltage = ina219.getShuntVoltage_mV(); 
 +  busvoltage = ina219.getBusVoltage_V(); 
 +  current_mA = ina219.getCurrent_mA(); 
 +  power_mW = ina219.getPower_mW(); 
 +  loadvoltage = busvoltage + (shuntvoltage / 1000); 
 + 
 +  // Print results 
 +  Serial.print("Bus Voltage:   "); Serial.print(busvoltage); Serial.println(" V"); 
 +  Serial.print("Shunt Voltage: "); Serial.print(shuntvoltage); Serial.println(" mV"); 
 +  Serial.print("Load Voltage:  "); Serial.print(loadvoltage); Serial.println(" V"); 
 +  Serial.print("Current:       "); Serial.print(current_mA); Serial.println(" mA"); 
 +  Serial.print("Power:         "); Serial.print(power_mW); Serial.println(" mW"); 
 +  Serial.println(""); 
 + 
 +  delay(2000); 
 +}
 </code> </code>
 +**Key Functions Explained**
 +
 +  * //begin():// Starts I2C communication. It uses address 0x40 by default.
 +  * //getBusVoltage_V():// Returns the voltage between GND and the load (V-).
 +  * //getShuntVoltage_mV():// Returns the voltage drop across the 0.1 ohm resistor.
 +  * //getCurrent_mA():// Returns the current flowing through the sensor.
 +  * //getPower_mW():// Calculates power based on the current and bus voltage. 
 +
 +**Calibration for Accuracy** 
 +
 +The library includes built-in calibration modes to improve precision for specific ranges: 
 +
 +  * **Default:** 32V, 2A (Used if no other function is called).
 +  * **setCalibration_32V_1A():** Increases precision for current measurements up to 1A.
 +  * **setCalibration_16V_400mA():** Highest precision for low-voltage, low-current projects. 
  
-==== Example codes ==== 
-none 
 ===== I²C topics on lamaPLC ===== ===== I²C topics on lamaPLC =====
 {{topic>i2c}} {{topic>i2c}}
Line 42: Line 133:
 \\ \\
  
-{{tag>ENS160 ScioSense gas-quality i2c communication sensor arduino code}}+{{tag>CJMCU-219 INA-219 INA219 breakout_board i2c communication sensor voltage current arduino code CJMCU}}
  
 This page has been accessed for: Today: {{counter|today}}, Until now: {{counter|total}} This page has been accessed for: Today: {{counter|today}}, Until now: {{counter|total}}