@redplc/node-red-rpi-mcp3424 v2.0.5

@redplc/node-red-rpi-mcp3424

Node-RED node for mcp3424 18bit adc using with redPlc nodes

mcp3424 analog to digital converter

• 12..18bit Conversion Resolution.
• Four Analog Inputs.
• Each input can be disabled.
• Internal Voltage Reference.
• Internal Oscillator.
• Programmable Data Rate 3.75 SPS (18bits) to 240 SPS (12bits).
• The PGA offers input ranges from ±256 mV to ±2048 V.
• I2C Interface with Eight Pin-Selectable Addresses.
• Works also for mcp3421..mcp3428

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.
• If other type then mcp3424 used, set correct parameter (see table below).
• 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

Address Pin Connection

Supported Devices

Example

This example reads temperature from sensor LM35 (DZ). The temperature sensor LM35 (DZ) outputs voltage 10.0 mV/°C. The sensor measures in the range of 2°..150°. Therefore the output is 20mV..1500mV. The module node mcp3424 is set for input CH1 and CH2 to Input-Range 2048mV. Other adc inputs are disabled. The redPlc calculate node divides adc value to 10. The redPlc export nodes reads the analog variables and sends to Dashboard gauge.