TeensyBoy

What is a TeensyBoy ?

TeensyBoy is just a ArduinoBoy code port for a Teensy uC.
What is ArduinoBoy? ArduinoBoy is a device using a Arduino (developped by Trash80) that enable MIDI capabilities for a old Nintendo GameBoy using special software like LSDJ, nanoloop, mGB.

Why porting ArduinoBoy on a Teensy ?
There is several reason but the most important one is that teensy is capable to emulate a Midi compliant device using midi, so TeensyBoy is using USB Midi instead of classic midi. So plug it in your USB port and it is automaticaly detected as a midi device.
The other reason are the price of a teensy is lower than a Arduino, it is much smaller, TeensyBoy will need less components that a ArduinoBoy (not optocoupler for example), using USBMidi library, code is less complicated, etc...
The code for Teensy is based on the Original ArduinoBoy created by Trash80, most of the code don't have changed.


The code is finished but still need tests and tweaking :

• LSDJ slave mode : finshed and working
• LSDJ Master mode : finshed and working
• LSDJ keyboard mode : finished and working
• Nanoloop mode : finished but cannot test it (don't own nanoloop)
• mGB mode : finished and sems working need further tests.
• LSDJ map mode : not tested yet
• LSDJ  Midiout : not tested yet

All tests done are just the functionality working or not, i don't ow n a ArduinoBoy so i can't compare both.
I don't know if it less responsive or if some thing is not working as expected, if someone want to do tests or compare with the ArduinoBoy please feel free to contact me.

Note : all sysex stuff has been removed because it need much more time to port it, and not sure if it is a lot used by chipmusicians. (sysex stuff seems to add config via maxmsp patch)

TeensyBoy schematics :

Teensy Cabling diagram :

Blurry Picture of the testing device :

Code will be available on my googlecode page once all mode been tested and working.

noizeInaBox temporary "shop" is available

I will finally create a small online shop for few devices i've created.
So currently there is no official online shop but i created a page with the things i sell.
You can find the shop page in the "tab" between Acceuil and Bookmark ..

noizeInaBox DMG deep bass PCB mount

Currently working on my Deep Bass DMG PCB mount.
It will be a full headphone PCB replacement with 2 new 3.5 mm audio jack. so you won't need to desolder the original DMG headphone jack.
For sound output it will use high quality OxiCaps.

It is impossible to find a 3.5mm jack with the same size and feature as the original gameboy one. (independent normally connected switch), i found a suitable one but with a normally open switch. so i needed to add a 5V cable to it to be able to do the Headphone/speaker switch.

As the prosound jack is the same i've a normally open switch left, which i don't know how to use it for.
i was thinking of some start/select illumination when you plug the prosound jack in.
globally it is a switch that close when you plug the prosound jack in. so it can be used for anything.
if you have a good idea, please let me know.

noizeInaBox Selectable GB Clock working fine.

I soldered and tested the noizeInaBox Selectable GB Clock and it's working perfectly.

By connecting  VCC or GND to the A and B pins, you can select the desired frequency .





Some pictures and Scope screenshots

 compare the size with a GB battery.

if you look carfeully you can see a short between 2 pins of the IC, this is normal, i forgot a trace on the PCB during PCB creation .. huuuu ..
There is also 3 pad on the board, it is to set a default "value" the the pin B. For example make a short between pad B and GND then add a SPDT swith on GND, VCC and Pin A, will make a 4Mhz/2Mhz selectable oscillator for your GB (if you don't want lower selectable freq).


Some scope trace:
You can see that the frquency is not correct, because there is some drift in the freq. due to the way a tested it, the circuit was plugged on a breadboard then from breadboard to the GB.
also, the GB was powered by a very crappy switching power supply.

The original  GB crystal.











If someone is interested i've a few to sell, with component already soldered. just drop me a email.

my selectable GB clock PCB just arrived

I've build a precision selectable Gameboy clock module which got 4 selectable frequency.
1: 4.194304MHz
2: 2.097152MHz
3: 1.048576MHz
4: 524.288kHz

The board is very small 13 mm , and by adding 2 switchs, you can select theses frequencies.
It's time for some SMD soldering.
Some pics :

sorry for the crappy pictures.


 

DMG Deep Bass Prosound à la noizeInaBox

After looking at the DMG schematics, i got the idea to bypass the whole audio path of the gameboy and recreate my own output to see if we can get a better sound.

The idea behind this is to get better "pro-sound" output whit more BASS, because the DMG 1uF coupling caps will kill all deep bass.

I saw somewhere that a trick was to short the 1uF caps, but was a quite strange way of doing this because you will get the DC offset directly in the phone amp.

So my way of doing a prosound is connect directly at the CPU output (easier to solder directly before the 1uf caps) and add another circuit for DC coupling and High Z output leaving the original circuitry for headphone and speaker intact.

Schematics will come soon ..

Results : As expected, we get a much better bass response, for bass i mean sub bass(20-50Hz)

Some audio examples from LSDJ with associated the frequency analysis
I've tested with the same "song" each time with the classic prosound (pre-pot) and with my new pro-sound version using different caps value.
Prosound output directly connectin to my Mac internal input and saved without any compression (PCM 16bit ). No sound post processing.
 Sorry for the "song" but  is only a Bass test, not a full track as i don't know LSDJ that  much

Sound example Original Prosound

Using Pre-Pot Classic Prosound on DMG-01
Original Prosound Spectrum analysis : 

                                        Peak 36 Hz = -21.2dB




Sound example noizeInaBox Prosound using 2u2 Cap
noizeInaBox Prosound 2u2 Cap
Prosound using 2u2 Spectrum analysis :

                Peak 36Hz = -17.9dB ...  +3.3dB  than orignal prosound  .. yeah .. i like sub bass



Sound example noizeInaBox Prosound using 10u Cap :
noizeInaBox Prosound 10u Cap
Prosound using 10u Spectrum analysis :

 Peak 36Hz = -17.6dB ...  +3.6dB  than orignal prosound  .. yeah .. will buy a subwoofer :)


Sound example noizeInaBox Prosound using 100u Cap
noizeInaBox Prosound 100u
Prosound using 100u Spectrum analysis :

         Peak 36Hz = -17.8dB ...  +3.4dB than orignal prosound  .. nothing more ..


I know the  spectrum analysis look quite identical,but look closer at the lower frequencies (20-50Hz) and remember that 3dB more is like double power.

In order to do some better testing, i needed to use white noise, luckily the Gameboy got a noise channel so i tried the same spectrum analysis using the Gameboy white noise (white noise normally is all frequencies in the same time at same level) :

Original Prosound using white noise Spectrum analysis:

                                         50Hz = -44dB  ... look at 20Hz ..


noizeInaBox Prosound 10u cap using white noise Spectrum analysis:

                     50 Hz = -41dB  +3dB  than orignal prosound  and re look at 20 Hz..

noizeInaBox Prosound 100u cap using white noise Spectrum analysis:

                                          50 Hz = -41dB   +3.dB  than orignal prosound

My Conclusion :
Will build my nexts prosounds using my circuit because i like deep bass. i think the selected cap value will be 10u because you don't gain anything more with a bigger cap.
Another remark.if there is some low freq. noise, they will not be filtered with this prosound.
This method need  more testing because it is only the first tests, but look good .
Didn't tested yet if this affect in any way the headphone or speaker output.
And remember that is is only for "enhance" sub bass 

As it need more components, i will do a SMT PCB with some Oxicaps.
If it works fine, you will see soon on the market the noizeinabox prosound pcbmount 

Finished DMG-01

I just finished my Game boy DMG-01

It doensn't have much funky mod, only the classic

• Promod sound mod
• Green 3 Led backlight
• Black screen protector
• custom painting
• Super Gameboy CPU