PINE64
Just sharing - Printable Version

+- PINE64 (https://forum.pine64.org)
+-- Forum: PINE A64(+) (https://forum.pine64.org/forumdisplay.php?fid=4)
+--- Forum: Pine A64 Hardware, Accessories and POT (https://forum.pine64.org/forumdisplay.php?fid=32)
+---- Forum: DC Power In (https://forum.pine64.org/forumdisplay.php?fid=35)
+---- Thread: Just sharing (/showthread.php?tid=952)

Pages: 1 2 3


RE: Just sharing - frewind - 05-05-2016

(05-05-2016, 04:42 PM)queonda Wrote: Frewind, do you have a link to the one you bought on amazon prime?

https://www.amazon.co.uk/gp/product/B00ICR1UB6/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Should have it tomorrow (that will be Saturday 6th May UK), will post a report when I get it on.


RE: Just sharing - queonda - 05-05-2016

Cool, let us know how if it works for you and if you like it.

Sent from my SAMSUNG-SM-G935A using Tapatalk


RE: Just sharing - rahlquist - 05-05-2016

I just ordered a new one today as well but its coming from aliexpress so 3 week minimum http://www.aliexpress.com/item/Digital-Dispay-3V-30V-Mini-Current-Voltage-Charger-Capacity-Tester-USB-Doctor-QC2-0-quick-charge/32616678486.html


RE: Just sharing - tkaiser - 05-06-2016

(05-05-2016, 10:35 PM)rahlquist Wrote: I just ordered a new one today as well but its coming from aliexpress so 3 week minimum http://www.aliexpress.com/item/Digital-Dispay-3V-30V-Mini-Current-Voltage-Charger-Capacity-Tester-USB-Doctor-QC2-0-quick-charge/32616678486.html

But the problem is still that all those tools that are equipped with a type A receptacle measure on the wrong side of the cable and don't answer the most interesting question: for how much voltage drop is the (most probably crappy) USB cable between PSU and Pine64 responsible for: http://goughlui.com/2014/10/01/usb-cable-resistance-why-your-phonetablet-might-be-charging-slow/


RE: Just sharing - rahlquist - 05-06-2016

(05-06-2016, 01:31 AM)tkaiser Wrote:
(05-05-2016, 10:35 PM)rahlquist Wrote: I just ordered a new one today as well but its coming from aliexpress so 3 week minimum http://www.aliexpress.com/item/Digital-Dispay-3V-30V-Mini-Current-Voltage-Charger-Capacity-Tester-USB-Doctor-QC2-0-quick-charge/32616678486.html

But the problem is still that all those tools that are equipped with a type A receptacle measure on the wrong side of the cable and don't answer the most interesting question: for how much voltage drop is the (most probably crappy) USB cable between PSU and Pine64 responsible for: http://goughlui.com/2014/10/01/usb-cable-resistance-why-your-phonetablet-might-be-charging-slow/

Yes this is true, but having two testers (one that has a microusb in) I can test cables. Wink

Power Supply-->New USB Tester-->Cable Under Test-->Usb Tester with MicroUSB in-->any load.

Ideally I need some usb and microusb breakout boards but the above will suffice.


RE: Just sharing - tkaiser - 05-06-2016

(05-06-2016, 05:41 AM)rahlquist Wrote: Yes this is true, but having two testers (one that has a microusb in) I can test cables. Wink

Power Supply-->New USB Tester-->Cable Under Test-->Usb Tester with MicroUSB in-->any load.

Sure, you can then test cables. But you're also not new to this SBC world and you know already how bad Micro USB used for DC-IN is in reality. The average Pine64 backer that follows the recommendation to buy these cheap powermeters to be attached on the wrong end of the cable will fail to understand how important low resistance is (AWG 20 gauge rating preferred).

A powermeter that can be attached directly to the Micro USB port would be the way better recommendation since this easily shows the real problem: Undervoltage. Both the aforementioned link as well as this old thread might give the idea what might happen if you're using the wrong cable: http://forum.lemaker.org/forum.php?mod=viewthread&tid=8312&extra=page%3D1


RE: Just sharing - frewind - 05-08-2016

(05-05-2016, 05:06 PM)frewind Wrote:
(05-05-2016, 04:42 PM)queonda Wrote: Frewind, do you have a link to the one you bought on amazon prime?

https://www.amazon.co.uk/gp/product/B00ICR1UB6/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Should have it tomorrow (that will be Saturday 6th May UK), will post a report when I get it on.

Does what it said it would do. The display flips every couple of seconds between Volts & Amps. Attach a couple of pic's so you can see what it's like..


RE: Just sharing - rahlquist - 05-08-2016

(05-06-2016, 06:09 AM)tkaiser Wrote:
(05-06-2016, 05:41 AM)rahlquist Wrote: Yes this is true, but having two testers (one that has a microusb in) I can test cables. Wink

Power Supply-->New USB Tester-->Cable Under Test-->Usb Tester with MicroUSB in-->any load.

Sure, you can then test cables. But you're also not new to this SBC world and you know already how bad Micro USB used for DC-IN is in reality. The average Pine64 backer that follows the recommendation to buy these cheap powermeters to be attached on the wrong end of the cable will fail to understand how important low resistance is (AWG 20 gauge rating preferred).

A powermeter that can be attached directly to the Micro USB port would be the way better recommendation since this easily shows the real problem: Undervoltage. Both the aforementioned link as well as this old thread might give the idea what might happen if you're using the wrong cable: http://forum.lemaker.org/forum.php?mod=viewthread&tid=8312&extra=page%3D1
Unfortunately as voltage sensitive as most SBC are the flip side of it is that most dont understand that almost every "affordable" device that measures current consumption does so by running the input voltage through a resistor of a known value and measuring the drop across it. So to measure current the input voltage is being lowered across a resistor to calculate the current used. If you were to daisy chan several of these meters together you could watch the drop from one to the next.


RE: Just sharing - frewind - 05-08-2016

So the question is do these cheap devices help with Pine64 power metering of not?


RE: Just sharing - benpope81 - 05-08-2016

(05-08-2016, 07:59 AM)frewind Wrote: So the question is do these cheap devices help with Pine64 power metering of not?
Close enough.