Bug Filed on 12-24-2015: Graph - time axis


1. What OS? (Wheezy or Jessie)


2. What class/size SD card? (ex. class 10 16gb)

class 10, 16Gb, Samsung Pro

3. What Model Pi? (A+, A, B+, B, Pi2)


4. Please describe the bug / issue. Attaching any relevant screenshots would be very helpful! Thanks in advance.


please look on the graphs. even if between two consecutive values don’t have the same number of seconds(sometimes is 7 sec, sometimes is more) the distance is the same. for example in the below graph: 21:43:23/21:43:30/21:43:46/21:43:53 we have 7sec/16sec/7sec and the distance is the same on graph between these values.

PS Today, the issue is not solved



Hi Bogdan,

Thanks for this. The good news is that we’re reporting the data correctly. We will look into why there are different second intervals. I’m curious, what would be an acceptable real-time interval for data getting refreshed for these graphs?.. every 1 second? 3 seconds? Every 5 seconds, or even 10?



Recommend time and date stamping the sample rate at the instrument / Pi end from some selectable part of the setup menu ?
Perhaps getting the latest reading and storing into the history gadget based on some dashboard selectable option (along with say deg C and Min and max etc

Things like temperature hardly need updating more than 1 / min
Barro pressure / wind ave etc every 10 minutes…
Hardly need to fill the database etc…

~ Andrew


@ats1080s @booysenc @toshibass101 @josenunes34 @derikj @losgat @paulhargrove @chrispetty @dimitris @ftvplant Curious, what do you guys think is acceptable real-time interval for refreshing data on the graph widget?


@mark_john_rees @richardrob @Schnell


Thanks for input Andrew!


I think maybe being able to choose a refresh interval would be the best route, if possible. As I think on certain networks, SD cards, and model of Pi the refresh rate could be high or lower. Like a 1 second refresh rate on a Model A, slow SD card, and a cheap wireless connection might not be possible. While on a Pi2, fast SD card and wired connection, sub 1 second could even be possible.

While certain things wouldn’t need a fast refresh rate, who knows for some peoples projects. An extra setting when setting up the widget for refresh rate seems like a good idea, again, if it’s possible.


The underlying network / data structure perhaps needs to be understood a little better ? I am guessing data is sent direct to MyDevices ? Store, cache,spool and re sent back to your screen from server there ? I.e. in theory SD card size not an issue for storing trend data ?

  • Dashboard calls up data pointers, widgets based on data stored on server(s) ?
  • Pointers and value and slider and bar face-plate type displays just update direct with in coming data as it arrives.?
  • Disconnection of value, pointer = half light as at present. (good idea + message)
  • Graphing or storing or history store and dump gadget (I am proposing) has a resolution setting when setting it up something default about 1 minute sounds good.
  • Idea: A history dumping gadget dumps one, or selected multiple values / devices in range of ‘save as’ file types but recommend ‘agnostic’ CSV by default as these files open spready sheety type aps on just about any OS. ( This feature woul seem like a pretty powerful tool and make compare / compete well with serious scientific kit… I.e. you break into research and scientific community with respectable raw data formats. I for one will be streaming LoRa radio direct into Pi via ttyAMA0 from remote penguin nesting boxes. Cayenne with above features and a serial port connection will be The ‘Killer Ap’ for this project…
  • A ‘Make Public’ your trend data would be a nice feature. I.e. trend my penguin with your penguin nesting habits etc…
  • Recommend option to store digital even status of any IP or OP DI or DO as well. ( I see there is a slightly weird graph / plot option on the digital at present ) But this is actually very powerful to record an event against other variables.

Random thoughts… but not in any particular order or connection…

  • Data / sensors stream data to server ad hock / non time stamped and get stored with time, date stamp as they arrive.
  • (Optional) Settings (what we are after ?) Can take the data and regenerate it on anything from live (present settings) or selected time base by selecting the resolution required. Kind of as follows…
  • Option A direct, fast mode: It plots as fast as it arrives and pretty much like it is working at the moment. This is handy + super simple for beginners. It feels very connected, e.g. servo slider gadget and water flow meter… Or filling a tank etc… Responsiveness here = wow factor. It has good feel and appeal…
  • Option B is recommended for the above graph database type display. Default time interval of 1 sample per minute would be a ball park figure but again this could be a setting in the setting up steps.
  • I see the option of being able to select and extract single line Own, and/or Public project data and export it into a database export feature as pretty powerful… Al most another gadget.

~ Andrew



the above issue is still active. will it be solved? in my opinion is very important aspect of a graph.

Thank you


Agree it will be nice to see this working even in a basic format like set the sample rate which will approximate the X axis resolution.

I imagine the ‘History’ feature / database part will take a bit more sorting out.
Great when we get there…

~ Andrew


We’re working on it :slight_smile:


@Schnell @picaxe @bogdan_bogodai

Implemented a new History Graph feature. Let me know what you think?