node-red-contrib-sm-lkit

This is the node-red node to control Sequent Microsystems Learning Kit Card

Manual Install

Clone or update the repository, following the instrutions from the first page.

In your node-red user directory, tipicaly ~/.node-red,

~$ cd ~/.node-red

Run the following command:

~/.node-red$ npm install ~/lkit-rpi/node-red-contrib-sm-lkit

In order to see the node in the palette and use-it you need to restart node-red. If you run node-red as a service:

~$ node-red-stop
~$ node-red-start

Usage

After install and restart the node-red you will see on the node palete, under Sequent Microsystems category 6 new nodes:

LKIT 0 10V in

This node reads the 0-10V input channel. The read is triggered by the message input and output can be found in the output message payload as a number representing the voltage readings in volts.

LKIT 0 10V out

This node controls the 0-10V output channel. The value in volts is set dynamically as a number between 0..10 thru msg.payload.

LKIT 4 20mA in

This node reads the 4-20mA input channel. The read is triggered by the message input and output can be found in the output message payload as a number representing the current readings in milliamps.

LKIT 4 20mA out

This node controls the 4-20mA output channel. The value in milliamps is set dynamically as a number between 4..20 thru msg.payload.

LKIT MOT out

This node provide control to the card DC motor driver You can control the torque and the direction of rotation setting msg.payload between -100 and 100.

LKIT OPT in

When used in input mode the node shows only one port, the output port. The node monitors the input designated in the input channel dropdown menu. Whenever the selected input channel changes a new output will be produced indicating the new state of the channel (grouneded or open).

In input mode no output is produced upon intial deployment of the node.

Read Mode Operation

In read mode both an input and output port are shown. An output message is generated whenever a message is received at the input port. The contents of the msg.payload are ignored and the output is triggerd only by the reception of the message.

The input channel to be read may be designated either in the input channel dropdown menu or by the msg.channel value of the input message. To use the msg.channel value delete the channel number from the input channel dropdown.

The only valid value for msg.channel are numeric 1, 2, 3, 4 and strings "1","2", "3", and "4". All other values will produce an error message and no output will be produced.

Debouncing: the value of the input channel is determined by reading the signal at a short intervals (default of 25 msec) until two reads produce the same value. This becomes the output value. In input mode an output is only produced if two successive reads differ from the current store value.

LKIT RELAY

This node set one relay. Set one relay with the value received in msg.payload You can specify the relay number in the edit dialog box or programaticaly with the input message msg.relay.

LKIT LED

Controls LED GP1 - GP4 on the Sequent Microsystems Learning Kit Card. There are two modes of operation: single mode and group mode. The mode is selected in the node edit

Single Mode Operation

In single mode operation msg.payload controls the state of a single LED. The LED to be controlled may be defined in the node editor or in msg.led.

The msg.payload value may be numeric, string or Boolean.

• 0, "0","off", false - Set LED off
• 1, "1","on", true - set LED on

All other values will result in an error message.

Selecting and LED in Single Mode

The LED to control is selected either in the node editor or by msg.led. If msg.led is define it has priority over the selection in the node editor.

The msg.led value may be numeric or string.

• 1, "1" - Select LED GP1
• 2, "2" - Select LED GP2
• 3, "3" - Select LED GP3
• 4, "4" - Select LED GP4

Group Mode Operation

In group mode msg.payload control all four LEDs (GP1 - GP4) as unit.

The msg.payload value may be numeric or string.

*numeric - 0, 1, 2... 15 *string - "0", "1", "2"... "15"

The value of the msg.payload value is interpred converted in to a binary number and applied to all four LEDs. GP1 is the least significan bit and GP4 is the most significan bit. For example, and AN msg.led balue of 0 or "0" means all LEDs are off and an *msg.led" of 15 or "15" means all LEDs are on.

All other values of *msg.payload in group mode will result in an error message.

LKIT BUTTON

This node provide acces to the pushbutton on the card. It sed the sate of the button only if is changed thru msg.payload.

Important note

This node is using the I2C-bus package from @fivdi, you can visit his work on github here.  The inspiration for this node came from @nielsnl68 work with node-red-contrib-i2c. Thank both for the great job.