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<p>The power issue is pretty tough I think. Do you want to allow
charging from both sides (12v dc jack and eoma-5v0) or does the
power from the card only act as additional power for the system
(without charging and just taking the load off the battery)? How
do you want to control the power switch (SY6280) and detect
whether the card is passive or active (taking power/providing
power)?</p>
<p>These are just a few thoughts I wanted to share …</p>
<p>Julius<br>
</p>
<br>
<div class="moz-cite-prefix">On 21.02.2017 03:21, Luke Kenneth
Casson Leighton wrote:<br>
</div>
<blockquote
cite="mid:CAPweEDwMsfite3HzurkMYjEXOQ=bTdfaWP6bCj5un8pzp3wt=A@mail.gmail.com"
type="cite">
<div dir="ltr"><br>
<div class="gmail_extra"><br clear="all">
<div>
<div class="gmail_signature">---<br>
crowd-funded eco-conscious hardware: <a
moz-do-not-send="true"
href="http://t224.mjt.lu/lnk/AEUAHpcBGOsAAAAAAAAAAGbE2wkAASHlFNUAAAAAAAZHgABYrdnezmYpWJbKQ_mFjaTA2bFqdAAGAjk/1/-aIogf3mnMjIUFEMDU--Og/aHR0cHM6Ly93d3cuY3Jvd2RzdXBwbHkuY29tL2VvbWE2OA"
target="_blank">https://www.crowdsupply.com/eoma68</a><br>
</div>
</div>
<br>
<div class="gmail_quote">On Mon, Feb 20, 2017 at 1:07 PM,
Internet <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:internet@devpi.de" target="_blank">internet@devpi.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div>
<div dir="auto">I took another look and i am pretty
satisfied with the results ;). </div>
</div>
</blockquote>
<div><br>
</div>
<div>yeah, thank you for encouraging me to do it. </div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div>
<div dir="auto">However, a few things still need
attention (i wrote it down on <a
moz-do-not-send="true"
href="http://t224.mjt.lu/lnk/AEUAHpcBGOsAAAAAAAAAAGbE2wkAASHlFNUAAAAAAAZHgABYrdnezmYpWJbKQ_mFjaTA2bFqdAAGAjk/2/l_snLoC-GCz7kClnOIURFQ/aHR0cDovL3QyMjQubWp0Lmx1L2xuay9BRUFBSHE5YldSa0FBQUFBQUFBQUFHYkUyd2tBQVNIbEZOVUFBQUFBQUFaSGdBQllxdW93NTNBTF9lS2lURUtMRkQyY1BmUzI2d0FHQWprLzEvOENTNUpuWUh3ZkdKaDZZeHpzS1oxZy9hSFIwY0RvdkwzSm9iMjFpZFhNdGRHVmphQzV1WlhR"
target="_blank">rhombus-tech.net</a>)<br>
<br>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>ok let's go through them:</div>
<div><br>
</div>
<h2 id="gmail-pcb3-powerboard"
style="font-size:1.4em;line-height:1em;margin-left:1em;color:rgb(0,0,0);background-color:rgb(255,255,224)">PCB3
- Power Board</h2>
<ul
style="color:rgb(0,0,0);font-size:medium;background-color:rgb(255,255,224)">
<li>connect thermistor for BQ24193 USB OTG Charger between
BAT_NTC and GND (not TS which is wired to the fuel
guage)</li>
</ul>
<div><font color="#000000" size="3">yep, cut/paste error
there</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<ul
style="color:rgb(0,0,0);font-size:medium;background-color:rgb(255,255,224)">
<li>change DVCC to SYS-V (otherwise LEDs won't work)</li>
</ul>
<div><font color="#000000" size="3">yep done</font></div>
<ul
style="color:rgb(0,0,0);font-size:medium;background-color:rgb(255,255,224)">
<li>pin 2 of connector J2 (to PCB1) should go to VCC-5V0
(we need power for the EOMA68 card)</li>
</ul>
<div><font color="#000000" size="3">ah no. rrright, the
way it works is:</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">* EOMA68 Card Power is
actually "OTG-like". as in, you should expect it to be
*reversible* on demand, because there could actually be
an OTG charger plugged into the card, providing power
*in* to the Housing. this is why the SY6280 is
required.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">* the laptop's main
components need a *separate* 5.0V power rail, for the
USB Hub, Audio, LCD, USB2 connectors etc. etc.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">* power could actually
come *in* through the EOMA68-5V0 line and has to go *in*
to VBUS... which... argh, is missing so that needs
sorting.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">* power can also go
*out* through the EOMA68-5V0 line (from VBUS) when the
bq24193 is put in "boost" mode (this is for OTG power
compliance) ... which is missing and entirely defeats
the purpose of *using* the bq24193 in the first place :)</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">*sigh* so still have to
sort that out, creating a two-way power path between
VBUS and EOMA68-5V0 at *specifically* 5.0v, coping with
1.5A sustained current, and under user-control...
preferably without using too many components. SY6280's
are my favourite "power cutting IC". there's one spare
pin on PCB3 J4 which could be used to control its
enabling.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">my first guess at a
circuit would be a schottky diode pointing from
EOMA68-5V0 to VBUS to act as "power in to VBUS" and the
SY6280 to act as "power out". however, a *five amp*
power regulator is going to be needed on VIN to ensure
that the input voltage never exceeds 5V (which it could
at the moment).</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">thoughts appreciated.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3">.</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
<div><font color="#000000" size="3"><br>
</font></div>
</div>
</div>
</div>
<br>
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