Yet Another Pi Zero Portable!!

AluLagoa

First of all, sorry for the necro...

Great work!
This inspired me to make my own portable.

So, you run your setup straight from the 3.7v 2000mah lipo. How much play time does it give you?

moosepr

@AluLagoa necro!! ha ha!!

I did a runtime test, launched an N64 game and let the intro video run, so the pi should have been working pretty hard.

I got 10 hours on the test, but im not 100% sure what capacity the batteries are. My usb power meter claims it was 2500mah that the battery took to get to full, although this is sometimes misleading, as the voltages are different.

if we multiply the 5v charge by the 2500mah current (2.5amps) we get 12.5 watts. now the battery will actually be taking 4.2 volts to charge, so divide our wattage by our voltage actually gives us 2.98 amps, so its possible it is actually a 3000mah battery!

AluLagoa

@moosepr Thanks for the info!

I am planing on doing a similar project, but inside a case of some sort.
Have you ever updated your build to be inside a case?

moosepr

@AluLagoa i did intend on popping the guts inside a GBA case, then i got sidetracked trying to reduce the pcb overhang so i could get the 2.8" ili9341 to work, then i got carried away making custom pcb's to join a pi and an ili9341, and kinda forgot my initial project!!

AluLagoa

Regarding the battery.
People on a FB group are insisting that i need 5V 1.2A to power the 0.
But i can see from your project that a 3.7V lipo can handle it.

So, is it safe to run a 0 directly from a 3.7V lipo?

moosepr

@AluLagoa well I have never had an issue. The internals of the pi run at 3.3v or less. The main reason why there is the 5v input is because it is the standard for usb devices, so to be sure any usb device can work, we need 5v.

That said, some usb devices don't really need 5v, I have wireless and memory sticks that are fine at lipo voltages.

I think the main reason why 1.5 amp power supplies are recommended is to account for full power zero, with a camera, and some devices on the usb.

With a simple TFT and zero setup like this, it's only drawing 300mA, so as long as you battery can safely deliver that, your golden. Just watch out for low battery situations, the pi will start acting weird below 3v, and the battery shouldn't really be taken below that anyway, or you will damage it

AluLagoa

@moosepr Thanks again for the info.

As this is my first handheld, decided to go with external power from a power bank. In a future build I will implement internal power.

moosepr

@AluLagoa yeah they are a great way to get power easily! And they look less dodgy in airport security! 😛

retroprogrammer

@moosepr Can I ask you which tutorial exactly, you followed to connect the TFT screen

moosepr

@retroprogrammer I picked up bits from across the internet, and eventually made my own! The link is in my signature 😁