# Unit 8 CRC (look up table)

**URL:** https://discourse.nodered.org/t/unit-8-crc-look-up-table/70720
**Category:** General
**Created:** [16 November 2022 14:41 UTC](https://discourse.nodered.org/t/unit-8-crc-look-up-table/70720 "2022-11-16T14:41:25Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [17 November 2022 12:17 UTC](https://discourse.nodered.org/t/unit-8-crc-look-up-table/70720/2 "2022-11-17T12:17:19Z")

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CRC has been covered a few times.

Here is a worked example...

> [@Help on CRC-8 function](https://discourse.nodered.org/t/help-on-crc-8-function/34354/9):
>
> Assuming you meant 0x74 0x52 0x07 0x02 0x03 0x15 0xd2 has a CRC of 0xd2 then even that C code doesnt give 0xd2 Assuming you meant 0x74 0x52 0x07 0x02 0x03 0x15 has a CRC of 0xd2 then even that C code doesnt give 0xd2 - you get 67 (or 0x43) C version... [image] Click [here](https://repl.it/@StephenMcLaughl/crc8) to see it in action Additionally, my interpretation of that c code in JS function results in the same CRC [{"id":"aa6441fb.6f381","type":"function","z":"56a2925d.72edac","name":"Calc CRC","func":"var crc= 0x85;\…

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