RuuviTag as a Weather Station

lauri · June 29, 2017, 9:26am

This topic is dedicated to comments and conversations about the following RuuviLab tutorial:

If you don’t see any comments yet, don’t be afraid to be the first one to contribute!

Matti_S · July 1, 2017, 5:50am

Hi,

Do you have generated data about battery usage with Weather Station use?

In simple, how long you can use RuuviTag with one battery?

And how easy it is to stretch lifetime of battery?

otso · July 1, 2017, 6:57am

Hello,

Most comprehensive real-world measurements can be found in live demo: https://graphs.2kgwf.fi/dashboard/db/ruuvi?panelId=15&fullscreen&from=1494947351371&to=1498891772143

The battery voltage can go down to 2 V or so.

Current consumption of weather station is around 28-38 µA depending on transmission power, CR2477 battery should last for 2-3 years indoors. Stretching the battery life is easiest by lowering the transmission frequency, 8 µA current consumption can be achieved. At that consumption the limiting factor for lifetime is coin cell shelf life. PM me if you want to have a precompiled package with lower transmission rate, later we’ll make the tags configurable by Bluetooth.

Mcmxii · September 22, 2017, 4:46pm

Hi, what is the current transmission rate for Weather Station and how is the progress of making the transmission rate configurable? thanks

otso · September 25, 2017, 6:56pm

Hello,

Latest firmware transmits at 2 Hz in URL mode, 1 Hz in RAW mode.
April firmware transmits at 2 Hz in both modes.
Right now easiest way to configure transmission power and is to change the setting in configuration and recompile. [EDIT] Same for intervals.

Currently both accelerometer and BME280 can be configured over GATT, however there is not exact date on when the transmission power and interval is configurable. Probably sometime during 2017.

lauri · September 25, 2017, 7:00pm

FYI, the latest Ruuvi firmware transmits at +4dBm on both of the modes (RAW and URL). The hardware supports max +4dBm.

meisseli · January 10, 2018, 10:58am

My battery from Kickstarter-batch went out last week. Ruuvitag was mainly used in sauna.

otso · January 10, 2018, 11:15am

Thanks for letting us know. The tags ship nowadays with CR2477 which should last longer.

henri · January 12, 2018, 6:55pm

How long time it last?

miha · January 15, 2018, 12:36pm

Hi,

Is this now possible ie. adjusting interval or transmission power? I’d like to see my RuuviTag to send data maybe every 15sec. Thank you.

otso · January 16, 2018, 8:46am

Adjusting intervals is possible by recompiling firmware. An unofficial tag which sends always in raw mode once per 5 seconds at +4dBm can be downloaded from https://drive.google.com/open?id=0B0x2wz-pfcjwYlFwcWhOeWYxMk0.

Having rarer interval does not bring any concrete benefit, as the lifetime of the tag becomes limited by lifetime of the battery itself

tomko · September 25, 2018, 7:39pm

Winters are cold in Finland. What is the spec of the batter I need to look for?

Will this one do?
https://industrial.panasonic.com/ww/products/batteries/primary-batteries/lithium-batteries/coin-type-lithium-batteries-cr-series/CR2450

EDIT: this adds extra cost to the tag, not happy.

otso · September 26, 2018, 6:21am

I’ve used standard CR2477 batteries in freezer near -30C, but as the battery manufacturer of standard battery does not promise the battery will work at that temperature the tag might shut down.

CR2450HT are high temperature range batteries, they should reach from -40 to +125 C.

interferenc · February 11, 2019, 4:39pm

Hey Otso,

Would you be so kind and point out which configuration setting in which file sets the transmission frequency?

Thank you in advance.

otso · February 12, 2019, 8:45am

github.com

ruuvi/ruuvitag_fw/blob/master/ruuvi_examples/ruuvi_firmware/bluetooth_application_config.h

#ifndef BLUETOOTH_APP_CONFIG
#define BLUETOOTH_APP_CONFIG
#define APPLICATION_DEVICE_NAME         "Ruuvi"                         /**< BLE name displayed in scan response. */
#define APPLICATION_DEVICE_NAME_LENGTH  5                               /**< number of characters in above string, excluding null */
#define APP_DEVICE_NAME                 APPLICATION_DEVICE_NAME         /**< TODO: Refactoring **/
#define APP_DEVICE_NAME_LENGTH          APPLICATION_DEVICE_NAME_LENGTH
#define APP_TX_POWER                    4                               /**< dBm **/
#define INIT_FWREV                      "2.5.9"                         /**< Github tag. Do not include specifiers such as "alpha" so you can accept ready binaries as they are **/
#define INIT_SWREV                      INIT_FWREV                      /**< FW and SW are same thing in this context **/                             

// milliseconds until main loop timer function is called. Other timers can bring
// application out of sleep at higher (or lower) interval.
#define MAIN_LOOP_INTERVAL_RAW        1280u
#define ADVERTISING_INTERVAL_RAW      1280u //!< Apple guidelines Specify at most and exactly 1285 ms interval. Account for 0 - 10 ms random delay in advertisements
#define MAIN_LOOP_INTERVAL_RAW_SLOW   ((5*1285)-5) // Apple maximum interval * 5
#define ADVERTISING_INTERVAL_RAW_SLOW MAIN_LOOP_INTERVAL_RAW_SLOW
#define ADVERTISING_STARTUP_PERIOD    5000u // milliseconds app advertises at startup speed.
#define ADVERTISING_INTERVAL_STARTUP  100u  // Interval of startup advertising
#define APPLICATION_ADV_INTERVAL      ADVERTISING_INTERVAL_RAW //!< Default value for driver

This file has been truncated. show original

interferenc · February 12, 2019, 9:00am

Thanks for the quick help!

Can I ask what variable you need to change from these to reduce the transmission frequency to for example 15 seconds? The APPLICATION_ADV_INTERVAL? Or some of the loop timers?

Thanks in advance.

otso · February 12, 2019, 11:17am

Loop timers control the rate at which the sensors are read but not the sampling rate of sensors themselves.

ADV_INTERVALs control the bluetooth transmission rate. If you set it to higher than the loop timers same data will be sent several times, if slower some data won’t be sent.

Valid range for the bluetooth advertisement rate is 100 ms … 10 000 ms, lower or higher should return error from the softdevice.

interferenc · February 12, 2019, 11:33am

Okay thanks!

So it is not possible to set it to 10010 as that is higher than the max value. Is it okay if I set it to 9090?

And this would mean that the some measured data will not be sent, as the loop timers are lower values, meaning the loop will execute like 5 times between transmissions. Do I understand this right?

otso · February 12, 2019, 12:06pm

Actually the limit is a bit over 10 000, so 10 010 would be ok. I just never remember the exact value. Basically yes, 9 090 would be ok.

yes

interferenc · February 12, 2019, 12:18pm

Great, thanks!