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58 lines
2.6 KiB
Markdown
58 lines
2.6 KiB
Markdown
node-red-node-serialport
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========================
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<a href="http://nodered.org" target="noderedinfo">Node-RED</a> nodes to talk to
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hardware serial ports.
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## Install
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To install the stable version use the `Menu - Manage palette - Install` option and search for node-red-node-serialport, or run the following command in your Node-RED user directory, typically `~/.node-red`
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npm i node-red-node-serialport
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During install there may be multiple messages about optional compilation.
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These may look like failures... as they report as failure to compile errors -
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but often are warnings and the node will continue to install and, assuming nothing else
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failed, you should be able to use it. Occasionally some platforms *will* require
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you to install the full set of tools in order to compile the underlying package.
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## Usage
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Provides three nodes - one to receive messages, and one to send, and a request node which can send then wait for a response.
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### Input
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Reads data from a local serial port.
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Clicking on the search icon will attempt to autodetect serial ports attached to
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the device, however you many need to manually specify it. COM1, /dev/ttyUSB0, etc
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It can either
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- wait for a "split" character (default \n). Also accepts hex notation (0x0a).
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- wait for a timeout in milliseconds from the first character received
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- wait to fill a fixed sized buffer
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It then outputs `msg.payload` as either a UTF8 ascii string or a binary Buffer object.
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If no split character is specified, or a timeout or buffer size of 0, then a stream
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of single characters is sent - again either as ascii chars or size 1 binary buffers.
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### Output
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Provides a connection to an outbound serial port.
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Only the `msg.payload` is sent.
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Optionally the character used to split the input can be appended to every message sent out to the serial port.
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### Request
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Provides a connection to a request/response serial port.
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This node behaves as a tightly coupled combination of serial in and serial out nodes, with which it shares the configuration.
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Send the request message in `msg.payload` as you would do with a serial out node. The message will be forwarded to the serial port following a strict FIFO (First In, First Out) queue, waiting for a single response before transmitting the next request. Once a response is received (with the same logic of a serial in node), or after a timeout occurs, a message is produced on the output, with msg.payload containing the received response (or missing in case if timeout), msg.status containing relevant info, and all other fields preserved.
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For consistency with the serial in node, msg.port is also set to the name of the port selected.
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