I’d like to build a project using the Seeeduino Stalker - Waterproof Solar Kit. Although it seems discontinued, it’s a nice module that many of us makers already bought and could put to a good use.
The kit is compatible with the GPRS Bee but I didn’t have much success with it and the documentation/support was very limited (or none), so I decided to use the FONA, which has behaved quite well for many users.
My question is for anyone using the FONA + Arduino for outdoor use, do you use a specific solar charging module or arrangement?
I am trying to power my project with a Solar-Panel as well, but i am still trying to figure out what works best. Currently i am using the Adafruit Solar-Charger which seems to work quite well if you connect Fona to the Battery or to the Bat-Pads (and not to the LOAD-Connector!). This way you are not making use of the load-sharing feature of this kit. I will try the loader from Sparkfun and Seeedstudio as well, will report findings in my blog.
snoller, I have been using the FONA outdoors and working out ways to save power. I can report data for over a week on a single 200mAH LiPoly cell. The question is whether the Adafruit Solar Panel could generate enough energy - on average - to keep the cell charged. Do you have some idea of the power output of the Adafruit kit in real world conditions?
Interesting, @chipmc I think that if you can get the FONA+Microcontroller to report data over a week with so few energy, then the solar panel should be able to generate enough power in such a long time frame.
@snoller haven’t tried the Adafruit solar kit yet. I will try to advance with the Seeeduino Kit and report my findings here.
So, here is what I am thinking. Suggestions welcome.
First, I will go with the Adafruit Solar kit (charger, panel and LiPoly battery) as it is very well documented and their support is great.
I am using the Arduino for my kit so it needs 3.3V and the FONA needs 3.6-4.2V. The Solar kit will run off the LiPoly battery (nominal 3.7V) when there is no sun and up to 6V when the sun is shining.
So, I was thinking a TI Switcher TPS63050 between the Adafruit charger ( on the LOAD pin), to the TPS63050 putting out 3.7V and a TI TPS73133 LDO linear to supply 3.3V to the Arduino.
Another wrinkle is temperature. You can’t charge the battery if it is too hot or too cold and the Adafruit kit has a Thermistor capability I will need to explore.
Let me know if you have any suggestions on how to make this better - was going to try as the weather gets better.
