Lower power usage? by Dom

[Administrator]

Hi

I'm interested in trying to get the maximum running time from navspark from a battery. Currently hooked up to a 700mah Lipo it only runs for a few hours which isn't great. Is it possible to turn off the GPS or anything else on the board to reduce the power consumption? Ideally i'd like to attach sensors to the board (movement, sound, water immersion etc) that would wake the GPS up and get fix, otherwise just run the board as low power as possible.

Thanks

Dom

[Administrator]

Hi I've the same problem

With 1000mAH battery , LCD and other stuff battery goes down quickly. My other project with more componentes battery time was 8 hours aprox. (by Jordi Gauchia)

[Administrator]

From other numbers I have, GLONASS/GPS module 45mA acquisition + LED 3mA + antenna 6mA = 54mA. Assume actual number higher by 50%, 54mA x 1.5 = 81mA. With 700mA battery you should get at least 8hr run time. If number in ball park, should run about 12hr.

Will check actual current consumption number next Monday and see if possibility to lower. (by Jason Lin)

[Administrator]

Testing full charged battery (with other charger).

Without discharging all the battery I had 2h battery duration (good for me , now), I think the problems I had were for battery charge (NavSpark module charges slowly¿?)
I try to discharge the entire battery and charge with NavSpark module and compare times of charge, discharge, etc..

More testing soon.... (by Jordi Gauchia)

[Administrator]

As I understand it, most embedded systems have the ability to turn off power hungry components to save on power. Is it not possible to deactivate the GPS unit and drop the board down to a low power mode? If not possible now, is it possible in the future with a firmware update? If this isn't possible it seems like a bit of a flaw in the navspark, as it will limit all sorts of potential tracking applications. It should be possible to run these boards for weeks or months with the right setup and batteries. (by Dom)

[Administrator]

In my case, I've used PWM pin to control Backlight of the LCD screen.

I'll use a timer to turn off the backlight when passed few seconds/minutes and turn off while push any key.

With this feature I'll save power of my battery. (by Jordi Gauchia)

[Administrator]

BAS40 schottky diode and XC62FP LDO introduce about 0.8V voltage drop at 50mA. NavSpark RFIC and internal Flash memory has 2.7V as operating voltage lower bound. Thus when battery discharge below 3.5V it may cease to function, as VCC33 falls below 2.7V. From battery discharge curve, battery is not completely depleted at 3.5V; this might explain shorter than expected operating time.

The board wasn't designed for intermittent mode of operation working for weeks in mind, so didn't have sleep modes.

[Administrator]

Hello,

I have a Navspark GL with the latest firmware and a internal GPS/GLONASS active antenna connected to the adapter board with a 2 GB Adata microSD, powered by a 3.7v 1000mAh Li-ion battery. No user program, I use the firmware logger.

I charged the battery for 10 hours with the internal charger (the light was still on, I guess it was still charging) and I got 8 hours logging time until it died. I got another charger that charges the battery in about 5 hours to 4.2V, it is rated at 500mA.

I got 25 hours of logging from this charge, it died at 3.19V.

Guess the included charger is very slow, I'm going to use the new charger from now on, it's tiny, I'll mount it in the same enclosure.

(by Io Mihai)

[Administrator]

Thank you Io Mihai for this interesting information. I think Adapter Board charge longer time yet battery operate shorter time is due to D1 voltage drop from NavSpark board, and D2 voltage drop from Adapter board, before 5V goes to SC806 charger IC. So less than 4V to charger IC, causing battery never able to reach near 4V, resulting in shorter battery operation time.

I think if you can short out D2 diode on adapter board, then battery can charge to higher voltage and operate longer. SC806 has input range 3.15V ~ 6.3V