Cheap powerboost way

[Oxodao]

Hi,

I have, from an older project, a TP4056 which can charge any Lithium battery at 1 amp so that is nice, plus it is a small thing so no problem.
Since the powerboost cost an insane price, I thought of only buying a DC to DC from ebay to crank up the voltage from 3.6 to 5v, but I'm facing two problems...

The first one is that in order to connect this, I need to get the wire from the TP4056 (Of the battery) to this board, and having it going through the power switch on top.. If I'm not mistaken, Adafruit's one got it through a mosfet so that the switch doesn't have +1A going through it constantly.. And adding one could maybe make the circuit too thick... anyway, my question was, how can I do this properly ?

The second problem is that the DC to DC converter will not have an under-discharge protection I guess, neither it has a led to show low battery so how could I handle this... I would really like to do some kind of percentage always shown on the screen though I am not good enough at electronics to do this...

Would this be dangerous to use it during it's charge with this kind of solution?

Or would I rather buy one of those already made 5V boost + charger than trying to salvage my charger ?

Anyone can help ? Thanks in advance


EDIT: For the percentage, why are these guys doing it by measuring the voltage ? Since the discharge curve of a lithium cell is not linear this is wrong isn't it ?

[tent]

yeah
and I also have same desire (powerboost 1000c has definitely outrageous price for what it is)
anyway check this thread so far for similar discussions http://sudomod.com/forum/viewtopic.php? ... &start=450
Anyway personally I hope I will be able to do it with a normal booster plus protector (over under voltage etc) plus this guy here:
http://lowpowerlab.com/atxraspi/#whatisit
or maybe a "poulu" is enough to do the button
of course no way to check battery level but I think I could live with that..?

[Oxodao]

This is some nice thing there though it is a push Buttons, i'd rather use a switch since it is a gbz

I end up buying it though I still want to work on a correct power supply for the pi..

[Fleder]

I can't help you if you want to use the parts that you already have.
But if you want to have a cheap solution with battery level, try this: http://www.banggood.com/Dual-USB-5V-1A- ... 31593.html
Without a battery level indicator, the wiki has got a cheap alternative for the PB1KC.

Also, the Pololu U3V12F5 is a great and really tiny step-up module, if you want to boost 2.5 and up to 5v.

[tent]

Hi Fleder,
that DualUSB5V1A definitely looks good but battery level seems to be limited to that lcd, right? not easy to use that info from a raspberry I suppose.. also the led seems not to be a low level indicator but there is almost no info about it.. otherwise might look as a great alternative to a powerboost 1000c but the enable (or other means to interface it with raspberries GPIO) would also be missing right?

tent:wq

[Oxodao]

I will probably try to do my own thing based on a atmega and few thing like that

[Fleder]

Hi Fleder,
that DualUSB5V1A definitely looks good but battery level seems to be limited to that lcd, right? not easy to use that info from a raspberry I suppose.. also the led seems not to be a low level indicator but there is almost no info about it.. otherwise might look as a great alternative to a powerboost 1000c but the enable (or other means to interface it with raspberries GPIO) would also be missing right?

tent:wq

I am not quite sure what you mean.
You want to see the battery level inside emulationstation?

I found a bit more information about this module here: http://m5.img.dxcdn.com/CDDriver/CD/219931.doc
or here: https://www.amazon.com/SMAKN%C2%AE-Lith ... B00WDQIA9W

And, of course, if you need a slightly different model: https://www.fasttech.com/product/145160 ... pcb-module
Look lower right. There you have all the different models.

[tent]

well the problem seems to be always the following: find a CHEAP and SIMPLE way to give (mobile) power to a GBZ and other portable device based on the PI0 or similar.
- fact1: raspberries with linux do not have a way to shut down like computer or laptop (a la ATX) by sending information to the PSU to shut down the power after OS was stopped first
- fact2: raspberries with linux do not have a way to sense if battery level is low when the device is portable (a la APM) by receiving a low bat singnal and undergo the shutdown of OS and PSU as above.

So far I was unable to spot something that was both CHEAP and SIMPLE or at least a close combination of it.
Using an Adafruit PowerBoost 1000C plus a ATXraspi is definitely NOT cheap.. maybe simple but not even that TBH..

- as Oxodao, what I have is a TP4056 as charger which is cheap and simple.
- a protection and booster circuit with selection of source, I have here a DLX-UPDC5V, which is cheap and simple in addition to that could be a
but this is missing any battery level indication and also there's no possibility to enable or disable the power.. not to speak wire this to GPIOs.
The item you suggest might maybe combine the above two but do they provide something in addition that we could use to solve fact1 and fact2 above somehow?

or any other ideas?

Kr,
tent:wq

[Camble]

@tent I am planning to use one of these boards for battery level sensing. Because the Raspberry Pi has no analog inputs, I'm hoping to use the tiny board to read analog battery voltage (through a voltage divider) and come up with some battery level overlay for my GBZ. I no longer use a Teensy, which is why I'm looking at this board, but anyone who still has a Teensy could add the functionality to that instead.

It's a long way off though and the last thing I need is another distraction. I'll probably spend some time on it once I actually finish my GBZ.

[Fleder]

@[mention]Camble[/mention]
that sounds interesting.
I am working on something similar right now, but with an LED instead of a Display or Software solution.
Let me know when you managed to make yours work.