ModBee Node UIO board library

Board support for the ModBee Node UIO, an ESP32-S3 industrial I/O module for
35 mm DIN rail.

ModBee Node UIO

Hardware only: digital and analog I/O, pulse counting, the HAT power enable,
the button and status LED, Wi-Fi bring-up, sleep and wake, and the I2C
expansion bus. No communication protocol is built in. Modbus, the ModBee
protocol and anything else run alongside as their own libraries.

The board


Microcontroller	ESP32-S3FH4R2, up to 240 MHz, 4 MB flash, 2 MB PSRAM
Digital inputs	8, 5-24 V DC, opto-isolated, two groups of four with separate commons
Digital outputs	8, 5-24 V DC, opto-isolated high-side (sourcing) MOSFET; 100 mA per output from the board supply, 500 mA with a separate supply
Analog inputs	4, ADS1115 16-bit; 0-20 mA as shipped, 0-10 V per channel by solder bridge
Analog outputs	2, GP8413 15-bit; 0-10 V as shipped, 0-20 mA per channel by solder bridge
Serial	2 x RS485
Expansion	2 x Grove I2C (3.3 V), two 8-pin stackable HAT headers
Power	5-24 V DC. USB-C powers the logic only; the analog outputs need at least about 9 V
Mounting	35 mm DIN rail, 118 x 58 x 45 mm

Whether an analog channel measures or drives voltage or current is a solder
bridge, not a setting. docs/HARDWARE.md has the pinouts,
the GPIO map, the power rails and every solder bridge, all taken from the
schematic.

Using it

#include <NodeUioAPI.h>

void setup() {
  uio().begin();
  uio().setInputRange(0, UIO_CURRENT);   // AI01 as shipped: 0-20 mA
  uio().setOutputRange(0, UIO_VOLTAGE);  // AO01 as shipped: 0-10 V
}

void loop() {
  uio().update();

  bool on = false;
  uio().digitalIn(0, on);
  uio().setDigitalOut(0, on);

  float milliamps = 0.0f;
  uio().analogIn(0, milliamps);
  uio().setAnalogOut(0, milliamps / 2.0f);   // 0-20 mA in, 0-10 V out
}

Everything goes through one class. docs/API.md is the
reference, and examples/NodeUioBasic is a complete sketch.

With OpenPLC

The OpenPLC function blocks for this board live in
modbee-openplc. They wrap this
library, so a program and a sketch see the same behaviour.

Building

PlatformIO, from this directory, builds the example:

pio run -e lolin_s3_mini

To use the library in your own project, see
Installing in the repository README.

Layout

src/
  NodeUioAPI.{h,cpp}        the public interface
  NodeUioTypes.h            enumerations, limits and scaling
  NodeUioBoard.{h,cpp}      the driver behind it
  NodeUioExpansion.{h,cpp}  the I2C expansion module framework
  NodeUioPulse.h            pulse count to rate
  lib/                      vendored drivers: ADS1X15, GP8XXX
examples/  docs/  schematics/  images/

src/ is the include root, so a vendored driver is reached as
#include <lib/ADS1X15/ADS1X15.h>.

Licence

AGPL-3.0, see LICENSE. The vendored drivers keep their own MIT
licences, in their folders: ADS1X15 by Rob Tillaart, and GP8XXX, a modified
copy of DFRobot's DFRobot_GP8XXX.