@redplc/node-red-rpi-ads1115


Node-RED node for ads1115 16bit adc using with redPlc nodes

ads1115 analog to digital converter

- 16bit Conversion Resolution.
- Four Analog Inputs.
- Each input can be selected Single-Ended, Differential or Disabled.
- Internal Voltage Reference.
- Internal Oscillator.
- Programmable Data Rate 8 SPS to 860 SPS.
- The PGA offers input ranges from ±256 mV to ±6.144 V.
- I2C Interface with Four Pin-Selectable Addresses.

Usage

- Install redPlc nodes.
- Use redPlc s-inject node for trigger update.
- Connect to first output on s-inject node.
- Daisy chain nodes in series.
- For logical operations use redPlc nodes.
- Data is exchanged with global context variable arrays.
- Array index is equal input number for easy handling.
- This node works on Raspberry Pi with 32bit or 64bit OS.
- Input voltage more than VCC can damage adc input.
- The output value is mV or adc raw data.
- Works also on Raspberry Pi 5
- Enable I2C with raspi-config.
- In this case i2c-1 is enabled.
- If you use i2c-0 port add

dtparam=i2c_vc=on

to /boot/config.txt,

then Pin27=SDA, Pin28=SCK.

- For other ports add this to /boot/config.txt.

Array Index Mapping

|Input|Array-Index|
|:----|:---:|
|A0|0|
|A1|1|
|A2|2|
|A3|3|

Address Pin Connection To

|I2C Address|ADDR Pin|
|:----|:---|
|48H|GND or open|
|49H|VCC|
|4AH|SDA|
|4BH|SCL|

Example

This example gets voltage and current from ADC and displays on Dashboard.

The module node ads1115 is set for input A0 and A1 to Input-Range 2048mV.

Other adc inputs are disabled.

2048mV is equal 50V on input A0 and 5A on input A1.

In rung 01 the adc values are scaled to voltage and current

and stores in analog variable MA0.0 and MA0.1.

Input scale MIN is 0 and MAX is 2048.

Output scale MIN is 0 and MAX is 50 (V) for voltage (input A0).

Output scale MIN is 0 and MAX is 5 (A) for current (input A1).

The redPlc export nodes reads the analog variables and sends to Dashboard gauge.