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Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Tue Nov 21, 2017 11:44 pm
by salami738
razer.93 wrote:
Tue Nov 14, 2017 12:39 am
Is it possible to remap some pin of the dpi screen in order to use the uart or i2c? Did you get any possibility of communication with an arduino for example? (except for the USB)
Hi, i would like to know how you can use I2C or UART with DPI enabled.
According to the documentation: https://www.raspberrypi.org/documentati ... rrypi/dpi/
there is no configuration in which Pin 3/5 (I2C) or Pin 8/10 (UART) are free.
So i think you have to use free pins and do it in software.

Is there a way to remap the dpi pins to other pins?

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Wed Nov 22, 2017 12:58 am
by razer.93
salami738 wrote:
Tue Nov 21, 2017 11:44 pm
razer.93 wrote:
Tue Nov 14, 2017 12:39 am
Is it possible to remap some pin of the dpi screen in order to use the uart or i2c? Did you get any possibility of communication with an arduino for example? (except for the USB)
Hi, i would like to know how you can use I2C or UART with DPI enabled.
According to the documentation: https://www.raspberrypi.org/documentati ... rrypi/dpi/
there is no configuration in which Pin 3/5 (I2C) or Pin 8/10 (UART) are free.
So i think you have to use free pins and do it in software.

Is there a way to remap the dpi pins to other pins?
I actually discovered that the arduino pro mini can be used both in keyboard emulation and serial port mode simultaneously, so problem solved for me!
Thank you tinkerBoy for sharing the informations!

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Thu Nov 23, 2017 12:16 am
by salami738
razer.93 wrote:
Wed Nov 22, 2017 12:58 am
salami738 wrote:
Tue Nov 21, 2017 11:44 pm
razer.93 wrote:
Tue Nov 14, 2017 12:39 am
Is it possible to remap some pin of the dpi screen in order to use the uart or i2c? Did you get any possibility of communication with an arduino for example? (except for the USB)
Hi, i would like to know how you can use I2C or UART with DPI enabled.
According to the documentation: https://www.raspberrypi.org/documentati ... rrypi/dpi/
there is no configuration in which Pin 3/5 (I2C) or Pin 8/10 (UART) are free.
So i think you have to use free pins and do it in software.

Is there a way to remap the dpi pins to other pins?
I actually discovered that the arduino pro mini can be used both in keyboard emulation and serial port mode simultaneously, so problem solved for me!
Thank you tinkerBoy for sharing the informations!
Hi razer.93,

i would like to know how you did this. Any code examples for me?
I am using an arduino pro too and used I2C to communicate with the raspberry. If i can use UART over USB, i can remove two wires.

greetings from germany!

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Thu Nov 23, 2017 2:16 am
by razer.93
salami738 wrote:
Thu Nov 23, 2017 12:16 am
razer.93 wrote:
Wed Nov 22, 2017 12:58 am
salami738 wrote:
Tue Nov 21, 2017 11:44 pm


Hi, i would like to know how you can use I2C or UART with DPI enabled.
According to the documentation: https://www.raspberrypi.org/documentati ... rrypi/dpi/
there is no configuration in which Pin 3/5 (I2C) or Pin 8/10 (UART) are free.
So i think you have to use free pins and do it in software.

Is there a way to remap the dpi pins to other pins?
I actually discovered that the arduino pro mini can be used both in keyboard emulation and serial port mode simultaneously, so problem solved for me!
Thank you tinkerBoy for sharing the informations!
Hi razer.93,

i would like to know how you did this. Any code examples for me?
I am using an arduino pro too and used I2C to communicate with the raspberry. If i can use UART over USB, i can remove two wires.

greetings from germany!
HI salami738,
I tested it on computer: import keyboard.h, start the uart with Serial.begin and in the loop function read from serial and put whatever char you read out from the keyboard, really fun! At the moment I don't have the sketch but it's very easy.
I used i2c too in the last gbz (I was using gpios for keys too) but now with DPI things are getting harder.

Greetings from Italy!

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Mon Nov 27, 2017 8:11 am
by Vineheart01
Great scott that front half is solid circuit-board without an all-in-one lol. Well done indeed!

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Tue Nov 28, 2017 11:10 am
by razer.93
Updates on the back?

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Thu Dec 07, 2017 11:25 pm
by tinkerBOY
razer.93 wrote:
Tue Nov 28, 2017 11:10 am
Updates on the back?
Update: Im almost done putting all the parts for the rear case. Im using a rgb led for power on, charging, low batt alert.
IMG_2494.JPG
IMG_2494.JPG (1.73 MiB) Viewed 2616 times
IMG_2495.JPG
IMG_2495.JPG (1.64 MiB) Viewed 2616 times
The Pro Micro has plenty of analog input pins and im using one for lighting an RGB led red when it's low battery.

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Fri Dec 08, 2017 10:19 am
by razer.93
tinkerBOY wrote:
Thu Dec 07, 2017 11:25 pm
razer.93 wrote:
Tue Nov 28, 2017 11:10 am
Updates on the back?
Update: Im almost done putting all the parts for the rear case. Im using a rgb led for power on, charging, low batt alert. IMG_2494.JPG
IMG_2495.JPG

The Pro Micro has plenty of analog input pins and im using one for lighting an RGB led red when it's low battery.
Good job!
What kind of circuit are you using for powering the lcd backlight?

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Fri Dec 08, 2017 12:33 pm
by salami738
Hi, I would also like to learn more about driving the backlight leds.
The "LQ035NC111" datasheet says 18.6V - 21.0V and max 20mA.

I found many solutions on the internet with pros and cons:

1) Using a boost converter aka constant voltage and adjusting the voltage to adjust the brightness.
Pros: Easy circuitry
Cons: No constant brightness, varies with led temperature. Led can be destroyed because there is no current limiting

2) Using a boost converter and a current limiter and adjusting the current to adjust the brightness.
I found an easy circuit for diy at: http://www.radio-electronics.com/info/c ... source.php
Pros: Constant brightness, constant with temperature, led wont be driven over the max allowed current at no circumstances
Cons: Complicated circutery

3) Using a ready made LED backlight driver, like: http://www.ti.com/product/tps61160
Pros: Can be controlled digitally via arduino or raspberry to set the brightness
Cons: I didn't found any fully soldered breakout boards, so we have to solder SMD and design a PCB

Re: [tinkerBOY] Game Boy Three - RPi3 and DPI screen in 24-bit mode [WIP]

Posted: Thu Dec 14, 2017 3:22 pm
by fdeluxe
Could you give some infos about the display refresh rate? I am using a DPI display in my current build and while I am avle to reach playable refresh rates they are still far from the ones I reach with composite or HDMI. I always wondered how Kite made his display run so smooth