The FemtoTX Motherboard Standard

https://github.com/hatonthecat/Solar-Kernel?tab=readme-ov-file#copenhagen 

The theory, analogy, and metaphor is- solar powered computers are possible, but most have just not realized there was a calculation to be made. (From Copenhagen, 2002, BBC4) 

I successfully tested the Ymin 10mAh, 20 Farad lithium capacitor- it runs continuously and it hasn't been recharged since I received it. Next step is testing a variable resistor, a potentiometer which is pictured in the 1st and 3rd videos to toggle the dimness. I also tested positively a 12V car W5W "dome" LED light that I bought from eBay in 2017 - a 10 pack for $0.99- unsure what kind of voltage it uses (when connected to this breadboard), but similar ones use around 0.2Watts. Green LEDS (not the tinted aspect) use the least power, though using green for everything isn't always preferred.  

Being so risk-averse when it comes to testing circuits, electricity is easier written about than tested. That said, I try to make time for actually devising miniscule experiments that test at least one or two things. I am also a very slow learner- I tend to accumulate a ton of idle knowledge and rarely organize the information towards something I actually can see a use for testing (and towards developing a more complex test or build!). The terms "move fast and break things" and "fail fast" doesn't interest me, or at least when it comes to testing circuits, as opposed to carpentry or metalworking (which I never do). Not only that, but "move fast and break things" is counterproductive for circuits at best and dangerous at worst. For this video, I was only able to test one thing- voltage. Granted, I also had an unused multimeter that I only tested once in 2021, and had been wanting to get some use out of it. Not to mention the breadboard and solar power managers that I have laying around in a box. But one step at a time- While the breadboard is pictured, it is not tested in this video. That will come next, once I figure out how to wire the minimum circuit necessary to light the red LED.

A positive result was that the voltage test resulted in a reading of 3.60V, of which the LIC is rated 3.8V. Not sure if that is less than par, or it is just less than 100% charged. Or something like that. The margin of error is somewhere between 0.5-1%, not enough to result in an incorrect reading of 5% margin error:

|Automatic ranging TRMS 6000 count

AC voltage: 6V/60V/600V (±1.2% + 5d), 750V (±1.5% + 5d)

DC voltage 600mV/6V/60V/600V(±0.5% + 5d), 1000V (±1.0% + 5d)

AC current 6mA/60mA (±1.0% + 10d), 600mA (±1.5% + 10d), 20A (±2.5% + 10d)

DC current 60μA/6mA/60mA (±0.8% + 10d), 600mA (±1.2% + 10d), 20A (±2.0% + 10d)

Capacitance: 6nF/60nF/600nF/6μF/60μF/600μF (±3.0% + 5d), 6mF/100mF (±5.0% + 10d)

Resistance: 600Ω(±0.8% + 10d), 6kΩ/60kΩ/600kΩ/6MΩ(±0.8% + 3d), 600MΩ(±1.2% + 10d)

Frequency: 100Hz/1000Hz/10kHz/ 100kHz/1MHz/10MHz (±1.0% + 3d)

Duty ratio: 1%~99% ± (1.0% +2d)

Temperature: -20℃-100℃ -4℉- 1832℉ (± 1.0% + 3)

Diode test, Continuity test, Good Sensitivity of NCV sensor

Full range overloaded protection, Data hold, Live test

Auto Shutdown: 15 minutes

Backlight and flashlight|

https://www.lcsc.com/product-detail/Lithium-Ion-Capacitors_Ymin-SLA3R8L2060813_C970391.html

Multimeter User UA19B guide: https://drive.google.com/file/d/1uLc5ZH09o1W1XA3oQ490vOcm_m7ylSJ0/view

https://www.amazon.com/gp/product/B08BRG4XN2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

There are some great tutorials on breadboards:

https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard/anatomy-of-a-breadboard#:~:text=Terminal%20Strips&text=You%20can%20see%20lots%20of,hide%20under%20the%20plastic%20holes 

If I haven't posted a project log in a while, it's probably because I'd like to have something more substantial to showcase in a video than a single test. But I'm ok with that too.

Note: the 9V multimeter battery is being replaced very soon! It will be interesting to discover whether the low battery level was causing a 5-6% measurement error rate, which would suggest it is actually 3.8V...

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An English version of the data sheet can be viewed here:

https://en.sekorm.com/doc/2768518.html

"The SLA3R8L2060813 from Shanghai Yongming Electronic is a Supercapacitor with Capacitance 20000 mF, Voltage Rating 3.8 V, Equivalent Series Resistance 500 mOhms, Temperature Operating Range -40 to 85 Degree C. Tags: Through Hole. More details for SLA3R8L2060813 can be seen below.

Product Specifications

Product Details

• Part Number SLA3R8L2060813
• Manufacturer Shanghai Yongming Electronic
• Description 20000 mF, 3.8 V, 500 mOhms, Electric Double Layer Supercapacitor

General

• Types of Capacitor Electric Double Layer Supercapacitor
• Capacitance 20000 mF
• Voltage Rating 3.8 V
• Equivalent Series Resistance 500 mOhms
• RoHS Compliant Yes
• Temperature Operating Range -40 to 85 Degree C
• Dimension 8 x 13 mm
• Package Type Through Hole"

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A 10mAh supercapacitor/hybrid capacitor would allow up to 10 hours of charge for a 1 milliamp hour Ambiq Apollo3 microcontroller! https://www.sparkfun.com/products/15444

Was able to fit a 5" screen in Pi-Top v3, thus considering use as a cyberdeck instead of main panel.

Got my Artemis Nano to power on completely with a 10.5W LED, far less than the 45W Cowboy Studio CFL I was using with the 2V, 160mAh panel in my previous log . Since the bluetooth LED is is blinking, it must be using around 5mW, which is probably not very efficient, although it is the only way I can connect [using an Adafruit Universal USB / DC / Solar Lithium Ion/Polymer charger w/ TI BQ24074) the 5W panel to the USB-C input of the Artemis Nano at the moment. Some efficiency loss is likely, since it travels through the 500mA boost converter.

Later I put the lampshade back on the Philips and was able to get a red LEDd, but it took a while for current to flow through the entire circuit. With some efficiency improvements (i.e soldering the 500mV boost and panel placement), it is very likely that the Artemis Nano can be powered in a more ambient condition (i.e not a bulb directly on the panel as in the above photo.)

I’ll also try my Powerfilm Dev-in-Basic w/ BQ25570 development kit sometime.

Sparkfun Artemis Nano https://www.sparkfun.com/products/15443

Powered by DFRobot Solar Power Manager Micro

https://www.dfrobot.com/product-1781....
Monocrystalline Silicon Solar Panel 2V 160mA 50*50mm

& 800 Lumen Philips 10.5W bulb 2700K.

The next step is to get the blue light that flashes when it boots with a standard 3.7V battery & recharge the battery at the same rate it discharges. A larger solar panel will easily work, but I had to unplug it because the Nano immediately started smoking, not realizing I was using the wrong 4.4V out with an Adafruit Solar Lipo Charger. Really important tip: Make sure you have the right regulated output or it will fry the MCU

I attended a webinar by E-peas, Epishine & Cap-XX, and found this slide helpful