Having watched some of the recent community meeting (I've not watched it all yet) there's a few things I should try and answer about the Solar Staker. Please note if you want to discuss the Solar Staker with me I'm regularly on Slack and IRC and monitor the Telegram Group, here and the
evergreencoin.org forums. I'm more likely to pick up questions or comments via those means rather than the community meetings.
For the Solar Staker the blocking point isn't really hardware at the moment, what I (and I hope this community) is aiming for is something that can be easily used by someone relatively new to crypto currency, that's low power (5W or less) and easy to keep updated. I'd also like to think we can come up with something that can run for decent amounts of time from solar energy. This requires more than just a single piece of hardware and is arguably a harder project than some of the big things we've crowd funded to pay for (Android wallet etc.)
On the same lines I've started writing a Design Brief, arguably something that should have been done 18 months ago before anyone started thinking about solutions (and before I got involved in EGC). Once it's a bit more complete I'll make the details available to anyone that's interested for comment. If we can make it something the community largely agrees on it makes any future discussions much easier.
HardwareHardware wise we have been looking at the
C.H.I.P. from
Next Thing, the main reason we liked it is due to all the things it has on board (meaning less we potentially have to do). Whilst waiting to find out about the future of the C.H.I.P. I've also been looking at (and in some cases buying) other things that might be a suitable alternative. For the majority of well designed and supported single board computers (SBC) there should be little effort moving between them.
I'll try and address some of the other SBCs I've considered in a second post (this one is already quite long)!
I've not really explored the android route partly as until very recently we've not had an android wallet that can be backed up. Buying an android phone without a contract also tends to be relatively expensive (at least in terms of the price point the Solar Staker is aimed at). When I've looked previously non contract android phones tend to be in the $70-$100 range (and that's from the online Chinese stores). Certainly not an expense I'm willing to spend from my own pocket for this project.
SolarThis is something Steven and myself have worked on (Steven has the foundation and faucet wallets running from solar). We've both been trying a few different options for solar charging and battery technologies.
Steven's efforts have mostly been around using a 12V lead acid battery with solar charge controller with my work been around using the Lipo charger built into the CHIP - both options have their merits and drawbacks.
Whilst it might look easy based on the plethora of solar batteries on the likes of Amazon and eBay please take some time to read what they actually say. For instance the [url url=http://a.co/h5CiNiu]first hit I got on amazon[/url] advertises itself as a solar charger, but when you read the details you find:
Please kindly note that it's comparatively slow for the solar charger to recharge itself via solar power, due to the limited surface of the solar panel.
Based on the limited information I calculate it will take 24 hours of strong, direct sunlight in perfect conditions to charge based on that solar panel. In reality you never get 100% output from a solar cell and in general no one gets 100% daylight so a week to recharge is a more realistic estimate of it's time to charge from solar.
For a 5000mAh lipo battery that may only give a couple of hours run time to some devices. A 10W android TV stick might not even manage 2 hours. Testing a similar capacity battery on my C.H.I.P. last year yielded around 15 hours (although that may reduce if it's doing a bit more work).
For my CHIP running off mains (USB Voltage and USB Current shown in the red box) this is the current power overview. This equates to about 3W (I actually had to refresh a few times to find some higher values, other refreshes gave around 1W)
One thing we've not really looked at yet is arranging for a clean shutdown of the device as the battery gets low and startup once there's enough charge in the battery, I think this would be relatively trivial on the CHIP (at least with a LiPo cell) but it may take some additional circuitry on other systems - this is important to have once we have a product to ship as sudden power loss can cause issues on a number of devices - meaning re-flashing is needed.
UseabilityI have the start of a web based interface for accessing the wallet over a wifi network, this is currently based loosely on the QT wallet interface however some bits may require changes to the current CLI wallet (which is currently being used on the back end). I think Steven is planning on showing some of the interface during the next community hangout.
I've also been working on ways to deploy and update the software on whatever device we deploy to - There seems little point providing a version that barely works and then requires a computer science degree to update it.
The majority of this work can be used across any Linux device we might choose to use. My development work for this has involved the C.H.I.P., Banana Pi and Raspberry Pi 3.
IssuesThere have been various discussions about what we need from this device in particular things like how much of the time it's active (a few hours a month vs 24/7). This has a significant impact on the design. This is part of what I hope to address by the Design Document I mentioned earlier in the post. There's also been discussion about security which may dictate what's sensible or not.
Also please realise that Steven and Myself are trying to provide something that's easy for an average member of the public to use (as is the ethos around several things EGC is trying to do). This means a fair amount of development work (probably more than has happened in many of the other EGC projects). And it's something that we've both largely funded from our own pockets and in our free time. We also have to work to pay the bills and have other interests and commitments which also demand time and money.
