Yet Another Pi Zero Portable!!
-
@gazredtyke I think there may be the details peppered though the thread. It is basically a pi zero, 8 buttons and a TFT screen. It's all wrapped rather haphazardly around a lithium battery, with a charge/protect PCB, and a microcontroller doing a bit of switching
-
@moosepr I've ordered a screen from china, I've got a few pi zero's, I've found the li po charge protector but I couldn't find the microcontroller, also will any li po battery around 2000 mAh do? Do you reckon I could use the guts of a usb snes controller for the input?
-
@gazredtyke with my testing, 2500mah got me 10 hours, so 2000 will get you about 8 hours.
The microcontroller is a uhex from dfrobot https://www.dfrobot.com/wiki/index.php/UHex_Low-power_Controller_SKU:_DFR0343
I did plan on adding a power level indicator and safe shutdown of the pi, but never got round to it. You could replace the microcontroller with a simple switch really
The controller route is a good idea, the PCB will have one side of each switch going to a common point. This will need connecting to one of the gnd pins on the pi, with the other side of the switch being connected to individual gpio pins
-
@moosepr thanks for that, I've got a 5200mah power bank that I don't use, would that just be too much?
-
@gazredtyke the only thing you need to watch with batteries is the voltage. If you use the power bank USB output then you will get 5v, but you will loose some of that capacity with the conversion. If you crack it open and use the raw cells you will get more capacity, but only get 4.2-3.3v from the cell. You can put anything as low as 3.3v into the 5v pins on the zero and it will work fine, but anything over 5v and the magic smoke will come out. The capacity will only alter the runtime. A 5000mah battery will just get you 20 hours runtime
-
@moosepr it says 3.7V 5200mAh 19.24Wh on it
-
@gazredtyke awesome, that's just under 21 hours runtime then! Will probably take like 6 hours to charge though! 😛
-
@moosepr overnight then! haha, would you mind if I got in touch when my parts arrive for some help?
-
@gazredtyke yeah no problem dude! If you start a post detailing the build, you will get lots of help from everyone!
-
@moosepr thanks mate, could you let me know which gpio pins are needed for all the connections? Can't quite make it out from the photo...
-
@gazredtyke I used this as a guide to connect the screen
http://marcosgildavid.blogspot.co.uk/2014/02/getting-ili9341-spi-screen-working-on.html?m=1Then the buttons, you can use any of the remaining gpio pins. You have to install some software on the pi that turns your pin input into keyboard commands, and in there you set what pin does what
-
@moosepr I think I've thought of another way, if i desoldered the micro usb I could just solder the usb wires directly to the pi couldn't I?
-
@moosepr infact scratch that, ridiculous idea!! I've just soldered 5 wires to a micro usb male, still smaller than the screen and battery when plugged into the micro usb port!
-
This is exactly what I need! I'll be making something like it when I get my hands on a zero. Have you played legend of zelda nes?
-
@rockyhill only briefly, might have to have another go now
want to get a tft into your project, look no further than here https://retropie.org.uk/forum/topic/7464/ili9341-tft-screen-guide
-
@moosepr
Oh man! 10 hours you say? great for trips.
Now one has to convince airport security to let something like this onto an air plane. -
@rockyhill yeah it managed to sit running the start movie on one of the n64 banjo kazooie games for 10 hours, although the controls stop working. I think the gpio buttons don't get a look in once the CPU goes full speed for n64
i am working on something that looks a little less dodgy. Waiting for the postman to come with my latest OSHpark order
-
@moosepr Hi again, as I said I would I have started a similar project, my idea to rewire a cheap usb snes controller worked, I've replaced the regular usb male with a micro usb male, I've tested it with my battery and the LIPO charger module, retropie showed up on my monitor and I configured my controller without issue. I have a couple of questions though....
Do I need the df robot microcontroller? What purpose does this serve exactly?
Also I order a 2.8" tft but it must be slighlty different to the 2.2" screen you used. The pins are different to the ones in the link you sent me, also it's a touch screen, is this an issue? -
@gazredtyke sounds like you are making progress, you should start a thread and add some pictures!
I'm basically using the microcontroller as a fancy switch! The plan was to add some kind of battery monitor and safe shutdown mechanism, but i never got that far really. I got carried away with new projects.
The 2.8 inch version of the screen should work the same as long as it is a ili9341 screen. It should mention the driver as being ili9341 in the listing you bought from. The touch screen will mean that there are more pins than I have. You can ignore the touch screen part and just use it like a normal screen.
-
I think I figured it out, I just wasn't looking properly, is VIN same as VCC?
Contributions to the project are always appreciated, so if you would like to support us with a donation you can do so here.
Hosting provided by Mythic-Beasts. See the Hosting Information page for more information.