how can i calculate crc16 using blocks?

Elias_Vieira · June 5, 2022, 12:32am

I needed to calculate this crc16 but I have no idea how or if it is possible to do this using block programming

ChrisWard · June 5, 2022, 12:38am

On GitHub there are example calculations of the algorithm in several different languages. You can try to mimic with App Inventor Maths Blocks, or you can run the JavaScript example from App Inventor (no internet required).

gist.github.com

https://gist.github.com/tijnkooijmans/10981093

crc16.c

uint16_t crc16(char* pData, int length)
{
    uint8_t i;
    uint16_t wCrc = 0xffff;
    while (length--) {
        wCrc ^= *(unsigned char *)pData++ << 8;
        for (i=0; i < 8; i++)
            wCrc = wCrc & 0x8000 ? (wCrc << 1) ^ 0x1021 : wCrc << 1;
    }
    return wCrc & 0xffff;

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ChrisWard · June 5, 2022, 12:44am

Evs · June 5, 2022, 12:46am

I don't understand how to use real programming codes😕

ChrisWard · June 5, 2022, 1:02am

Well, since the JavaScript is already written, follow the Guide on running a script and you should be fine.

SteveJG · June 5, 2022, 1:10am

A possible Block calculation is here> Problem with CRC calculation - #2 by ABG

Evs · June 5, 2022, 2:41am

could you tell me which part of the javascript would enter the data that I would like to create the crc ?