Re: Jolla Solar Half prototype
 

Sunny day today :) It seems that the CSD tool is showing negative current when the battery is loading even though there's is text "Charging" when it's positive too (I should have noticed this earlier...). The tool shows now -10 - +10 mA current when the phone is in sun (there's some snow in the air).

So the earlier results are ok but they have been just limiting the discharge current (though I don't still get how the battery can go from 85 to 87 % in 2 hours during the last test when it should have been going down to 83% :confused: (EDIT: this is because the phone was most of the time in stanby though I'm not sure did I have the NFC bug workaround in use during testing). So the panel gives at winter in Finland about 100-110 mA output, which is still 60-70 mA short from the max ouput. If the phone discharges at ~100 mA in idle (EDIT: Idle as in "screen on" and no software running. Standby current is about 10 mA when screen is of) , ~160-170 mA from the panel should result in 60-70 mA loading current. Better and a bit bigger panel should get to over 100 mA easily.

EDIT: Of course if the phone is shut down you'll get the ~100-110 mA more juice per hour.

Re: Jolla Solar Half prototype
 

Hi skvark,
I have a solar panel prized out of a solar charger and as I don't have a soldering iron (yet), I'm using copper tape to 'replace' wires.
My main confusion and question, is which of the GPIO pins am I to connect to on the rear of the phone?, I first thought it was the GROUND and 5V+ (which are side by side), am I right or wrong here?, I feel I'm so close to getting this working but am a little afraid of damaging the phone due to lack of 'electronics' knowledge - any info gratefully received,
Regards,

Re: Jolla Solar Half prototype
 

Yeah, connect the solar panel's '+' to 5V DC input and '-' to GND. Take a look at the page 14 in TOH technical specification. I'm myself just a SW dev with limited knowlegde about electronics :)

Re: Jolla Solar Half prototype
 

Thanks Skvark,
that is how I have it connected, but the CSD tool isn't indicating that any charge is being created.
The panel is definitely working, as I have a very powerful high intensity discharge lamp to work with (400 watts), which send my multimeter off the scale!, but I don't know what the specifications of the panel actually are.
I think perhaps I should find a different way to hook up to the inputs/outputs.
How have you made your connections?
Regards,

Re: Jolla Solar Half prototype
 

What's the voltage of the panel?
Do you have the panel datasheet or link to manufacturer page? Are you sure the connection to the pogo pins is ok (there's voltage in the copper tape, usually only the other side of the tape is conductive because there's glue at the other side)?

Re: Jolla Solar Half prototype
 

Hi,
i'd like to ask if these panels would be suitable for solar TOH:

http://www.flexsolarcells.com/PowerF...Components.php

I'd probably used two SP3-37 - but they make 6V - could this damage the phone?

Would the voltage drop enough (to 5V) when the battery starts charging?

Would it be possible to cover part of the panel to drop the voltage to 5V?

Thanks!

Radek

Re: Jolla Solar Half prototype
 

Hi,
sorry for a late reply and thanks for getting back to me.

PANEL DETAILS - The panel was removed from a solar charger, of which I believe is; 5.5v 100mA http://www.paramountzone.com/solar-m...ne-charger.htm

POGO CONNECTION - As far as I am able to see, my strips of copper tape are in contact and aligned with the pogo pins and the polarity is also correct. Yes, you're right the copper tape has adhesive.
https://scontent-a-lhr.xx.fbcdn.net/...28313292_o.jpg

COPPER TAPE - As you can see, I have run the copper tape in one length strips to the corresponding pins.
I realise this is not the best way to make the conenction, but it's all I have at my disposal, for now.
The original wires that were soldered onto the solar panel had left quite a blob of solder behind, so I feel quite certain, coupled with meter readings, that voltage is being carried along the tape, not that the Sailfish CSD tool seems to show any changes in voltage supply.
Regards,

EDIT: It only bloody works!! (My connection, where the old blobs of solder are just not quite making contact), but with reasonable pressure on the panel, it connects and charges! Yay!

https://fbcdn-sphotos-f-a.akamaihd.n...84424932_o.jpg

What do you glean from the reading on the phone's screen, Skvark?, good, bad?
Regards,

Re: Jolla Solar Half prototype
 

You need to compare the reading without panel and then with panel. That reading in the picture indicates that your phone is still discharging at a rate of 136 mA.

That 136 mA is imho very high discharge rate for the phone. My phone gives about 100 mA when running the discharge tool without the solar panel.

With the panel CSD tool shows discharging rate of 50-60 mA (lamp) / 0 - -10 mA (sunlight) (= panel gives 40-50 mA (lamp) / 100-110 mA (sunlight)). Do you have multimeter to measure the panel real mA output?

Re: Jolla Solar Half prototype
 

I myself use a 6V panel (fluctuates between 5-6V depending on light source), but I think that a step-down converter to 5V is necessary for non-proto stuff. I'll have to check what the phone reports as the voltage, those are multimeter values. Covering the panel partly may be possible, I have to test that too.

EDIT:

cat /sys/devices/platform/msm_ssbi.0/pm8038-core/pm8xxx-adc/dcin

Result: 4522986 Raw: 32421

So phone says 4,52 V (cloudy sky). This may get a bit closer to 5 V if I make better connections :D Take this with a grain of salt but it seems to be safe to use 6 V panels.

Re: Jolla Solar Half prototype
 

Oh, okay, seems I misunderstand how these things work. I see what you are saying now, I think. A quick peak now at discharging rate, shows it is around 115mA without solar panel.

I do have a multimeter. I'm no expert at using it. With a 20 watt lamp over the panel, I get an output of around 5mA (again I maybe reading this wrong), or do I add a zero and it becomes 50mA?
My apologies for being a dickhead where this is concerned, I did all this at school, many. many, years ago and have forgotten ALL OF IT! :D :(
Thank you for your help so far :)