Parts questions / first build

[LukeyD]

Hey guys/girls,

Been lurking for a long time now learning/researching and looking at all of the different great builds on here and have finally decided to take the plunge and build 2 myself one as a present and one for myself. I have soldered/coded before and I have some basic electronic experience.

This is where I intend to keep track of the parts I need and update you guys with how the build is going.

I have created an incomplete part list of the parts that I think I need if anyone wants to check it out or refer to for their own build, I am sure I have forgotten something though so I would wait until one of the pros has a look! I do not plan on building this over night as I know I will run into problems, have to wait on parts coming etc but I would be lying if I said I didn't want to get the parts ordered and start tinkering.

https://docs.google.com/spreadsheets/d/ ... sp=sharing

Onto the questions! (Sorry if these have been asked before but I did check first)

- Adafruit powerboost 1000c vs Gearbest 5V USB Power Bank Step-up Boost Module
What are the pros and cons of each board?
Will I still be able to have a battery monitor on screen if choosing the Gearbest?
Will I still be able to charge the DMG via the DC powerjack whilst playing?

Sd card to contrast wheel slot
Do people usually just position the pi so that the sd card slot is at the contrast port, or would I be better to have the pi positioned elsewhere and use some sort of a break out board?

Screen recommendations
What sort of screens do people recommend these days? I see a lot of people recommend the gear best screen, is it the following?
https://www.gearbest.com/development-bo ... 29447.html

Controls/Audio
In the above part list you can see that I have chosen to use an ATmega32U4 (teensy) for the controls with a generic common ground board I found on ebay, the reason I chose to do this was to keep as many pins on the rp0 free as possible for other stuff whilst avoiding the cost/wait of an AIO. I remember reading somewhere it is actually better to have the buttons wired to a teensy, if there are any disadvantages let me know!

Obviously not using an AIO board I will need to add some sort of amp to the build, are their any recommendations from you guys on what I should be looking at/using?

3d parts
I know I will need to use some 3d printed parts to keep the build looking clean, but what exactly are the parts that I need to obtain? On my list so far I have the screen mount, dc plug holder and switch holder. I would be willing to pay someonein the Uk with a 3d printer that would print and ship me these parts.

Thanks,
Luke

[tinkerBOY]

Hi Luke! Welcome to the forum!

One advantage of the Adafruit PowerBoost 1000c is it's smart load-sharing feature. It uses both power from the battery and charger when you're playing while charging not unlike the GearBest which always discharges from the battery even while charging. But since most of the time I always shutdown my GBZ first before charging, the GearBest 5v is good enough for me and it's very cheap. Yes you can use any battery monitoring module and charge while playing on both.

All of my builds I use the contrast area for sdcard accessibility. Most builds I've seen too.

For the audio amp the most common is the PAM8403 module.

Gearbest screen is what I recommend since it works with 5v out of the box no modifications needed. And here's how to wire the GearBest screen.

I also made a wiring diagram which you can use with any simple button pcb.

Good luck!

[LukeyD]

@tinkerBOY Hey man! Thank you, I was literally just having a look at your website. So would the gearbest still charge whilst playing, only slower because its draining straight from the battery?

That's good to hear what batter monitoring module would you recommend?

Do you position your pi so that the SD slot is at the contrast wheel area, or do you use a breakout board of some description?

I will have to have a look into the audio module and the audio side of things a little more, would I be able to use that module and still have audio cut out when I plug in headphones? I would like to have semi-decent sound through my headphones so even if there was a slightly up rated module I would have a look into that too.

Yeah I thought that someone would recommend that, is this the correct one before I place an order? https://www.gearbest.com/development-bo ... 29447.html

Awesome thank you for the wiring diagrams and the detailed response it is very much appreciated.

Luke

[rodocop]

Yes, it will charge while playing, not super fast though, as for battery monitoring, looks into an ADS1015 (cheap and easy, check out hoolyhoos combo script or mintybatterymonitor script, It will work with the ADS1015).

You can place the pi so the SD is accessible via the contrast port, like so:

I have this hot glued in place, but you can find 3d printed screen brackets with screw posts for the pi now.

SpoilerShow

Gearbest link is good, that's the screen most people use.

For audio, as long as you have a switching headphone jack the speaker will cut out with headphones plugged in.

Here are a few audio options: the pam8403 amp is cheap and works decent, but it is PWM which will have some static. I2s and USB audio are quite clear. With usb though, you will need a usb hub, if you plan to use any other usb devices. I2s is nice since it uses a few gpio pins, and doesn't take up the pi's single usb port. Any one of these three below will work, up to you what to choose. I have switched to USB or I2s though, and no longer use PWM audio in any of my builds.

USB https://www.ebay.ca/itm/5V-USB-Powered- ... 2304879364

I2s https://www.adafruit.com/product/3006

PWM https://www.banggood.com/3Pcs-PAM8403-M ... ds=myorder

[tinkerBOY]

Link to the screen and wiring guide is at http://www.tinkerboy.xyz/product/3-5-lc ... -boy-zero/.

Yes that's correct it's a bit slow on charging while playing. I don't usually charge while playing anyway.

Yes i always position my sdcard to be accessible via the contrast area.

On my v2.2 board with the Pro Micro i can use one of its analog pins to monitor the battery with a simple code to just blink a led light.

[LukeyD]

Yes, it will charge while playing, not super fast though, as for battery monitoring, looks into an ADS1015 (cheap and easy, check out hoolyhoos combo script or mintybatterymonitor script, It will work with the ADS1015).

Cool that is what I am after! Wouldn't the ADS 1115 also work with the same script and a few minor tweaks for more accurate battery monitoring?

This is the ADS1115 Module that I am thinking about ordering.

You can place the pi so the SD is accessible via the contrast port, like so:

I have this hot glued in place, but you can find 3d printed screen brackets with screw posts for the pi now.

SpoilerShow

I actually ordered a screen bracket for the 3.5" Gearbest screen that has a mount for the pi/ and rear tactile buttons.

Gearbest link is good, that's the screen most people use.

Ok so the screen has arrived and I have it wired up to test it out and to be honest the quality isn't great, I will be honest I wasn't expecting much but there is a decent bit of flickering. Would I be better to de-solder the connector on the screen driver board and wire directly? My wiring can be seen below:

https://photos.app.goo.gl/uzButrpL5kxtKbD38

https://photos.app.goo.gl/jjys3fRt6c5riU2LA

I think I need to get some single core shielded wire for the AV1 wire if you know of anywhere I could buy some? I cant seem to find any small shielded wires other than the one I scavenged from an old usb cord seen below, is this the type of shielded wire I should be using?

https://photos.app.goo.gl/Gf9EBYBhPm7nbQ9cA

For audio, as long as you have a switching headphone jack the speaker will cut out with headphones plugged in.

Here are a few audio options: the pam8403 amp is cheap and works decent, but it is PWM which will have some static. I2s and USB audio are quite clear. With usb though, you will need a usb hub, if you plan to use any other usb devices. I2s is nice since it uses a few gpio pins, and doesn't take up the pi's single usb port. Any one of these three below will work, up to you what to choose. I have switched to USB or I2s though, and no longer use PWM audio in any of my builds.

USB https://www.ebay.ca/itm/5V-USB-Powered- ... 2304879364

I2s https://www.adafruit.com/product/3006

PWM https://www.banggood.com/3Pcs-PAM8403-M ... ds=myorder

Is there a particular switching jack that I should be using to fit in the DMG-01 case so I can order a few?

I have already ordered x10 PAM8403 for the audio side of things (cheap as chips) but I will get one of the I2s to try it out if it is better, do I still need to use ferite beads and a high/low pass filter with the I2s?

I have been looking into speakers recently and people seem to be using a lot of different types of speakers is there any in particular that you would recommend to go with the I2s?

Apologies for all of the questions, just want to make sure I am ordering the right stuff and you guys all seem like GBZ wizards

Your help is very much appreciated
Luke

[rodocop]

Hey there, so yes, the ADS1115 will work, the script will need to be modified though. I have always used the 1015's so I am not sure on what actually needs to be adjusted in the script. If you browse this thread I think the answer is in there:

https://sudomod.com/forum/viewtopic.php?t=4585

As for the screen, I have found that the gearbest screen is the best of the composites. (for me at least), I see you have wired the ground to the pi's GPIO's, what I usually do is actually wire the ground right beside the white av wire (that hole is ground as well). It seems to help, at least I have noticed a difference when wired there, versus the GPIO or power strip. The screen should have came with some shielded wire, which is usually sufficient.

I have also soldered and removed the connector, and just kept the connector, I have seen no noticeable difference.

In regards to audio, these are the particular jacks I use, you can find them cheaper on aliexpress, but here is an amazon link.

https://www.amazon.ca/gp/product/B01M1P ... UTF8&psc=1

You will not need any filter with the i2s, it is pretty nice and clear on it's own. (even with pwm audio I have found the low pass filter does not help all that much, and I have skipped them in most of my builds) I use these speakers by the way 29mm, 8ohm 1/4 watt. This is where i got my most recent ones, but really any seller from ebay or ali will sell the same things. There are better quality speakers out there, but these cheapos work well I think.

[LukeyD]

Hey there, so yes, the ADS1115 will work, the script will need to be modified though. I have always used the 1015's so I am not sure on what actually needs to be adjusted in the script. If you browse this thread I think the answer is in there:

https://sudomod.com/forum/viewtopic.php?t=4585

As for the screen, I have found that the gearbest screen is the best of the composites. (for me at least), I see you have wired the ground to the pi's GPIO's, what I usually do is actually wire the ground right beside the white av wire (that hole is ground as well). It seems to help, at least I have noticed a difference when wired there, versus the GPIO or power strip. The screen should have came with some shielded wire, which is usually sufficient.

I have also soldered and removed the connector, and just kept the connector, I have seen no noticeable difference.

In regards to audio, these are the particular jacks I use, you can find them cheaper on aliexpress, but here is an amazon link.

https://www.amazon.ca/gp/product/B01M1P ... UTF8&psc=1

You will not need any filter with the i2s, it is pretty nice and clear on it's own. (even with pwm audio I have found the low pass filter does not help all that much, and I have skipped them in most of my builds) I use these speakers by the way 29mm, 8ohm 1/4 watt. This is where i got my most recent ones, but really any seller from ebay or ali will sell the same things. There are better quality speakers out there, but these cheapos work well I think.

Thanks for the quick response man, I will order some of both I actually just swapped the white for the yellow (AV1) & tried moving the ground before you replied, is this the spot you are talking about? it was the closest ground I could see on the pinout. Or do you literally mean the hole to the right of the yellow wire?

Unfortunately the wire it came with was not shielded at all (the wire I am using is the one it came with). I think I might try and remove the connector not to sure how yet but I will give it a go lol

Perfect mate, thank you for the links and response once again! I look forward to buying more parts

[rodocop]

I mean right beside the av wire, here is a pic of one of mine:

SpoilerShow

6-14-2018 8-58-08 AM.jpg (92.37 KiB) Viewed 6756 times

In this case I removed the connector and soldered my own wires (28 AWG silicone coated wiring). Removing the connector is not too hard. You can actually just snip the 4 pins on the back, and then snip the two support legs with flush cutters and pull the plastic stuff off. Then Just heat the pads and pull what ever is left or the metal legs with tweezers etc...