# Checksum questions

**URL:** <https://discourse.nodered.org/t/checksum-questions/100280>\
**Category:** General\
**Created:** [30 January 2026 07:19 UTC](https://discourse.nodered.org/t/checksum-questions/100280 "2026-01-30T07:19:08Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![EaB11](https://avatars.discourse-cdn.com/v4/letter/e/ecb155/32.png) [@EaB11](https://discourse.nodered.org/u/EaB11)\
**Post date:** [30 January 2026 07:19 UTC](https://discourse.nodered.org/t/checksum-questions/100280/1 "2026-01-30T07:19:08Z")

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hi all...

i am in the process of trying to get a gimbal for my camera to be controlled by node red using bluetooth... im not very experienced with this stuff and just kinda stumbling through at the moment...

i need to calculate checksums for some input values before sending the commands to the gimbal..

for example this hexadecimal input

0610030FFF

needs to produce the checksum output of

81BC

from what i understand this is a CRC16-CCITT checksum ? there is a calculator someone has made online already at this location

> **[Go Playground - The Go Programming Language](https://go.dev/play/p/F3CI8iqkd6l)**

this calculator produces the correct checksums and also appends the checksum to the initial input values.. so im wondering is there anyway to replicate this code in a function node ? if i could recreate the entire code in node red that would be great but essentially the main part i need is..

crc := crc16.Checksum(packet.Bytes(), crc16.CCITTFalseTable)  
binary.Write(packet, binary.BigEndian, crc)

i asked google and chatGPT but what they provided didnt output the correct checksums..

any help is appreciated.. thanks..

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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:** [30 January 2026 08:37 UTC](https://discourse.nodered.org/t/checksum-questions/100280/2 "2026-01-30T08:37:33Z")

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In the article "Use any npm module in Node-RED" there are several examples. One of them is [Example: Easy CRC](https://flowfuse.com/blog/2023/06/import-modules/#example%3A-easy-crc)

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<div class="post-metadata">

**Author:** ![EaB11](https://avatars.discourse-cdn.com/v4/letter/e/ecb155/32.png) [@EaB11](https://discourse.nodered.org/u/EaB11)\
**Post date:** [30 January 2026 15:43 UTC](https://discourse.nodered.org/t/checksum-questions/100280/3 "2026-01-30T15:43:49Z")

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thanks for the help... think i got it working.. cheers

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [30 April 2026 15:44 UTC](https://discourse.nodered.org/t/checksum-questions/100280/4 "2026-04-30T15:44:06Z")

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