- The Pad
The PCB was cutted then re-wired to keep original dir.-cross & btns
I found a tutorial here to perform that.
Then all buttons + GGear led were wired to a GPIO expander (SX1509 from SparkFun) that is readed by an Arduino ProMini 3.3v (8Mhz) because I had a lot of troubles by connecting it directly to the ARM SoC.
- The SoC
It's an AriettaG25 ARM SoC (not a raspPI one...).
It has 128MB of RAM, 400MHz cpu, SD slot & pluggable WiFi module.
no sound output, no HDMI output, so Why ?
Because is more even tiny than the RPI-0, it has 3 USB host ports, you can change the GPIO header layout. (& I've got 3 of those left in my toolbox...)
- The Sound Interface
I had 2 options :
- plug an USB SoundCard (but needed to rebuild a full kernel w/ good sound modules since the model that I have is not reconized )
- wire a DFPlayer Mini (Serial MP3 playback module that I already used in my previous console projects)
I choose the DFPlayer, it does require less POWER & requires no CPU resources... (& it's cheap !)
I finally plugged it onto the Arduino too to keep my others TTL lines free.
- The Screen
2 reasons to choose ILI9341 :
- I already used it in my projects
- there's an SD image file already built w/ Debian Jessie for the Arietta
It's SPI connecting, has 320x240px 64k colors