Historical values

[richard.jones]

Hi all, and I need to start with an apology, this may have been asked before but I’m new here and I couldn’t find it. In fact, I’m in at the deep end, it’s my first morning in Cayenne and week-1 with LoRaWAN!

Basically I’m gathering 24 hourly samples over a day to send in one Cayenne packet over LoRaWan, thus keeping airtime to a minimum. Can I graph this burst of values on a dashboard evenly spread through the day? I got a little hopeful when I found the openmobilealliance.org have a ‘Time’ data type (3333) but I believe it’s not available for Cayenne LPP?
I also read somewhere last night about adding 100 to the channel and using delta times which may be what I’m after, but I can’t locate that page today (wish I’d bookmarked it).

[shramik_salgaonkar]

you will have to send each sample on a separate channel.
Channel 501 —> Sample 1
Channel 502 —> Sample 2
…
Channel 524 —> Sample 24

[richard.jones]

Thanks, that crossed my mind, but I thought they would end up on different charts so I’ve not tried it.

[shramik_salgaonkar]

that the only option you have got. or you can enroll with our commercial platform which supports timestamp data. so you can send data with the timestamp. https://mydevices.com/work-with-us

[richard.jones]

Thanks, out of interest I found the page referring to Cayenne historical data, quite close to here!

Cayenne LPP 2.0

Hi everyone ! Please find below an extract with some addition to our Low Power Payload format starting on section 3.3. Feel free to share any comment or contribute, and enjoy ! Eric 3. Overview The Cayenne Low Power Payload (LPP) provides a convenient and easy way to send data over LPWAN networks such as LoRaWAN. The Cayenne LPP is compliant with the payload size restriction, which can be lowered down to 11 bytes, and allows the device to send multiple sensor data at a time or splitted into…

(wasn’t ready for the link to be replaced by the page!). It’s section 4.4 that’s of interest
I formed a packet with 4 historical values for my channel-2 (humidity), one from 40 minutes ago, another from 30 minutes ago, -20 and -10 minutes and sent it (Python)

lora.send(bytes.fromhex(‘68’+‘0960’+‘0A’+‘0708’+‘2B’+‘04B0’+‘14’+‘0258’+‘3C’), port=102)

The packet looks fine over on the TTN console but nothing changed on the dashboard.
payload 6809600A07082B04B01402583C
Would you expect this to work?
Did I misunderstand the format (I understand the deltas to be seconds ago)?
If it’s not for this purpose, what is it for?

[shramik_salgaonkar]

This is because timestamp data is not supported on the cayenne.

[richard.jones]

OK, thanks again for your assistance, I think I have 2 options:

1. Send the data when I get it rather than aggregating but I suspect that’ll cost me too much battery life.
2. Send it in one go, the graph will make no sense within the day, but over weeks will look OK. I can download the raw data and Excel it for the fine detail as I know it’s original sample frequency (it’s basically weather stats).

Do you know what Eric (eptak) was referring to in his post of 2018 that mentions “4.4. History Sensor Data”? Is that only available via a paid-for provider elsewhere? This project is for a customer who may go down that route if it’s available. I could always try replying to his post, see if he answers.

Richard

[shramik_salgaonkar]

@richard.jones

Is that only available via a paid-for provider elsewhere?

yes. the link is shared above.