Stream

DUELink Scripting language is built to be ASCII human-friendly. This works great; however, there are instances where speed or raw binary data is required, like when writing or reading a buffer.

A direct benefit of streams is in giving a language, such as Python an easy way to transfer buffers to and from the module.

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Usage

This is an example to send a buffer to the module. This example is for Python but other languages work almost exactly the same.

Samples

Script

Library only functionality.

Python

# write first 64 byte elements from byte_array to b1
duelink.Stream.WriteBytes("b1", byte_array) 
# write first 64 float elements from float_array to a1
duelink.Stream.WriteFloats("a1", float_array) 
# read 64 byte elements from b1 to byte_array
duelink.Stream.ReadBytes("b1", byte_array) 
# read 64 byte elements from a1 to float_array
duelink.Stream.ReadFloats("a1", float_array) 

MicroPython

// write first 64 byte elements from byte_array to b1
await duelink.Stream.WriteBytes("b1", byte_array);
// write first 64 float elements from float_array to a1
await duelink.Stream.WriteFloats("a1", float_array);
// read 64 byte elements from b1 to byte_array
await duelink.Stream.ReadBytes("b1", byte_array);
// read 64 byte elements from a1 to float_array
await duelink.Stream.ReadFloats("a1", float_array);

JavaScript

// write first 64 byte elements from byte_array to b1
duelink.Stream.WriteBytes("b1", byte_array, 64);
// write first 64 float elements from float_array to a1
duelink.Stream.WriteFloats("a1", float_array, 64); 
// read 64 byte elements from b1 to byte_array
duelink.Stream.ReadBytes("b1", byte_array, 64);
// read 64 byte elements from a1 to float_array
duelink.Stream.ReadFloats("a1", float_array, 64);

.NET

# write first 64 byte elements from byte_array to b1
duelink.Stream.WriteBytes("b1", byte_array) 
# write first 64 float elements from float_array to a1
duelink.Stream.WriteFloats("a1", float_array) 
# read 64 byte elements from b1 to byte_array
duelink.Stream.ReadBytes("b1", byte_array) 
# read 64 byte elements from a1 to float_array
duelink.Stream.ReadFloats("a1", float_array) 

Arduino

// write first 64 byte elements from byte_array to b1
duelink.Stream.WriteBytes("b1", byte_array);
// write first 64 float elements from float_array to a1
duelink.Stream.WriteFloats("a1", float_array);
// read 64 byte elements from b1 to byte_array
duelink.Stream.ReadBytes("b1", byte_array);
// read 64 byte elements from a1 to float_array
duelink.Stream.ReadFloats("a1", float_array);

tip

Stream can't be used directly by typing in ASCII commands, like when using the Console or a terminal.

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Mechanism

Understanding and utilizing Stream mechanism is only needed by advanced users. See the source code of one of the provided libraries for reference.

A Stream command initiates the request. Once this command is received and accepted by the device, the & symbol will be returned indicating readiness. The host can then send the entire binary data, exactly to the required byte count, or float count. Keep in mind that a float is 4 bytes.