Display Binary Data

[williamesp2015]

Hi @krzychb , I tested sending binary data (signed integer) and display multi-channel chart.
int16_t samples[Sample number];
uint8_t u8Data[Sample number*2];
......
u8Data[0]=samples[0]/256;//high byte
u8Data[1]=samples[0]%256;
.....
webSocket.sendBIN(socketNumber, u8Data, NN);
/////////// index.html
.........
connection = new WebSocket(host, ['arduino']);
connection.binaryType = 'arraybuffer';
........
var buffer = new Uint8Array(message.data);
var dataview=new Int16Array(NN);
dataview[0]=(buffer[0]<<8)+buffer[1];
...............
scopeSamples1.push({x: xVal, y:dataview[0]});
...............

[krzychb]

Hi @williamesp2015,

Thank you for update on developments with binary transfer and code snippets!

To skip copying data from samples to u8Data, did you consider something like:

webSocket.sendBIN(socketNumber, samples, NN/2);

I am currently busy with another project but return to this one soon 😄

[williamesp2015]

Hi @krzychb , Thank you for your comment. I couldn't do that because the function accept only unsigned byte.
bool sendBIN(uint8_t num, const uint8_t * payload, size_t length);

[krzychb]

@williamesp2015,

You are right. I did not consider the data type.
In such case I would cast uint16_t * data type to uint8_t * :

webSocket.sendBIN(socketNumber, (uint8_t *) samples, NN);

Krzysztof

[williamesp2015]

Hi Krzysztof. I want to remove Adjustable sampling threshold and sampling rate and anything that slowing visualizing highest speed EspScopeA0. Please advice. Thank you

[krzychb]

Hi @williamesp2015,

This looks like version Bravo that is already on my To Do list 😄

Have you been thinking about setting a fixed number of samples and threshold or rather introducing a separate command to set them up?