BurnedHead

A handheld, portable video game system designed with Kicad and programmed in C.

Description

The processor is the STM32F767ZG, a Cortex-M7 processor selected for the ample size of the instruction and data caches. Currently at the board bring-up stage, the functionality includes an RGB parallel interface, an MMC card socket, a 32MB SDRAM clocked at 108MHz, D-pad, 4 front facing buttons, 2 shoulder buttons, 2 joysticks, and a speaker. The device is powered through a Micro-USB connector or a rechargeable LiPo battery for portability.

The final product will load user-selectable ELF files off of the MMC compatible card into the external RAM and run them as a process.

The project originally began in Zig but is transitioning to C to reduce friction when integrating with libraries and vendor code and to allow progress without requiring fiddling with a language still in beta.

Building

Cloning the Repository

This repository uses submodules to manage dependencies.

git clone --recurse-submodules https://github.com/vegecode/BurnedHead.git

Building the Application

BurnedHead uses Makefiles. Navigate to the base directory of the clone, and point to the specific Makefile you want to build (currently only one):

Example:

make -f configurations/${CONFIGURATION_NAME}/Makefile

The resulting executable(s) are in ./build/${CONFIGURATION_NAME}

Debugging on the Target

Debugging is done using GDB in a shell with the JLink GDBServer providing the connection to the remote target.

Running the shell script ./debug/start_debug /path/to/elf_file will start the GDBServer and connect GDB to it, then a gdb script loads the executable and sets a temporary breakpoint at the reset handler.

A sample of some external RAM tests during board bring-up in a Vim/GDB session:

Another easy alternative if you are using a JLink debug probe is to use Ozone, the standalone debugger from Segger or Segger Embedded Workbench which are both free to use for non-commercial purposes.

Integrating with Eclipse should also be possible using the MCU GNU Eclipse plugins.

Hand-Assembled Revision 0 Board

The back of the first revision of the board was assembled using solder paste and a cast-iron skillet over a stand-alone burner for reflow. Some rework was required as applying the paste without a stencil resulted in uneven application. The front side components were hand soldered.

Renders

Attributions

Some symbols and footprints came from www.snapeda.com. See the library folder for the required license and attributions.