How to decode a ascii string in V3?

Application Development
1

Probably a stupid question:

I have the impression that the payload in the webhook is different :
I get :
“MjEuNjLCsEMxMDI0LjA2aFBh”

This is clearly not HEX.

2

It’s base64.

3 
echo -en "MjEuNjLCsEMxMDI0LjA2aFBh" | base64 -d | hexdump -C

00000000  32 31 2e 36 32 c2 b0 43  31 30 32 34 2e 30 36 68  |21.62..C1024.06h|
00000010  50 61                                             |Pa|

This indicates that you are using an innapropriately inefficient payload encoding.

  • Do not send numeric values as ascii characters, send them as numeric values using only as many bytes (or ideally bits) per field as strictly necessary for the range.

  • Do not send units as ASCII abbreviations, units should be managed entirely out of band by knowing the payload format of a given node

2 Likes
4

Thanks

I’m fully aware that the encoding is not for production.
The encoding/decoding is not on the critical path and is something rather straightforward.

5

These things tend to not get fixed and are substantially easier to do it right first time. As such we are really allergic to text based payloads. See this for a mini-how-to:

https://www.thethingsnetwork.org/docs/devices/bytes.html

1 Like
6

Hi

This is a test setup.
My plan is to send not that often, send quite some measurements and use about 4bits for pressure and 4 bits for temperature for relative changes. same, up to 7 up, up to 7 down and an escape code (with than another 4 bits or 8 bits).

7

Plans rarely withstand contact with reality.

We can’t do much about it, but as a matter of protocol / policy, we don’t support bad practise on the community network so you’ll have to make your own way.