hey luke,

I just wanted to put my suggestions on rhombus-tech.net but unfortunately i couldn't figure out how to add a new subpage. to keep everything tidy and clear this would be really helpful …

i also updated the specification for the pcb connectors, there was something wrong between pcb3 and pcb1:
sys-v was 4.2v directly from the battery but it is 5v and the first pin is ground instead of usb_otg_5v0

i will update the other specifications as well as i walk through the other schematics …

Julius Lehmann

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

On Sun, Feb 12, 2017 at 2:30 PM, Internet <internet@devpi.de> wrote:

First look at PCB3 is finished, it is of course possible I am missing something. Anyways, following caught my eyes:

1. the usb otg charger ic has two capacitors between regn and ground, total value: 11.5uF, datasheet says 1uF. probably no issue though
2. 10k thermistor for the otg charger is connected to voltage divider and through another thermistor to bat-v (fuel guage), datasheet says it should be connected to ground (i am not to sure about the guage though, reference application is pretty chaotic and complex)
3. status leds should be connected to sys-v (nothing to do if dvcc = sys-v)
4. EOMA68-5V0 is not connected to anything, this results in an unpowered card on pcb1 (which is bad); should probably be connected to vcc-5v0)
5. level shifter is completely unnecessary because lcd-vcc = vrefttl = 3v3; connect 10k pullup resistors to vrefttl and add pullup for chg_irq to vrefttl

TI bat IC is 1.8v.. wasn't happy with that.

 

1. because eoma68-i2c is not used on this pcb remove pullups

_great_.  encourages me to take a look and check.

 

I hope this helps and if I misunderstood something, please let me know. The fuel guage circuit is more complex than expected, I let you know if there is an issue.

Do you want me to put all this on rhombus-tech.net? If so, could you give me some instructions where and how to put it?

http://rhombus-tech.net/community_ideas/laptop_15in/pcb2/ then just work it out, put whatever you feel is appropriate and i'll review it and move / adjust if necessary.

 

Additionally, to edit the pages I need some kind of account creation password …

ah! sorry, i added that recently after there were attacks on the page -- it's "passwordreqd"

 

Julius Lehmann

On 11.02.2017 15:00, Luke Kenneth Casson Leighton wrote:

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

On Sat, Feb 11, 2017 at 1:33 PM, Internet <internet@devpi.de> wrote:

You are absolutely right. Putting comments separately is the best thing to do. I just found the edit button on rhombus-tech.net ;), this should definitely make things easier ...

 yay, magic.   also stops duplication and AOL-style me-too postings.  if anyone remembers the AOL bbs...

l.

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