This is a Spartan Edge Accelerator shield which implements all the hardware connections needed for zwenergy's gbaHD, no wires required! The PCB incorporates the GBA motherboard, Arduino Nano, and SNES controller port used in a typical gbaHD installation, and interfaces directly with the Spartan Edge Accelerator board via pin header connections.
Assembly of this PCB requires donor parts from a Game Boy Advance motherboard, and therefore also requires advanced soldering skills. Do not attempt this project unless you are comfortable and confident in your ability to desolder and solder both surface-mount and through-hole components, otherwise you risk irreparable damage to your original console and to this PCB. I claim no responsibility and accept no blame for any failed attempts.
READ THE DISCLAIMER SECTION ABOVE BEFORE CONTINUING
The PCB can be ordered via the following links:
PCBWay (Full disclosure - this link gives me a small commission from each order - if you're new to PCBWay, feel free to use my referral link to sign up and get $5 off your order)
Or feel free to order from your preferred PCB fab using the gerbers on this repo.
Board thickness of 1.2mm or thinner is recommended. 1.6mm will work, but soldering of some of the through-hole components may be more difficult.
There are a couple optional features on this PCB to keep in mind before ordering your parts:
Choice between an onboard ATmega328P or an external Arduino Nano
The onboard Arduino offers a cleaner look for the assembled PCB, but since ATmega chips are becoming prohibitively expensive during this chip shortage, there is also support for plugging in your own Arduino Nano via pin headers. These options are mutually-exclusive, pick one.
Master power switch
This may be useful for consolizer-style installations that use an enclosure, such that a toggle switch can be mounted to the case to switch power to the entire assembly while leaving the USB-C power supply plugged in. This is completely optional, since the power can be switched off using the Spartan Edge Accelerator's own switch or by unplugging the power supply.
The BOM below is separated between donor parts, required parts, and parts for optional features. Read carefully since the optional features may require components that are also listed in earlier sections.
Please source your own passive components, only values and footprints are listed for these.
| Reference(s) | Count | Description | Part Number | Comments | Purchase Link | |
|---|---|---|---|---|---|---|
| From donor GBA | U1 | 1 | AGB CPU | - | - | - |
| U2 | 1 | AGB SRAM | - | - | - | |
| P1 | 1 | Link port | - | - | - | |
| P2 | 1 | Cart connector | - | - | - | |
| EM1, EM2 | 2 | Common-mode choke | ACM4532-102-3P | - | - | |
| Required | C1, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C16, C17, C21 | 14 | 0.1uF 0603 | - | - | - |
| C2, C3, C4 | 3 | 100pF 0603 | - | - | - | |
| C15, C22 | 2 | 10uF 0805 | - | - | - | |
| D1, D4 | 2 | Green LED 0603 | LTST-C191KGKT | Or generic | https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_Lite-On-LTST-C191KGKT_C125098.html | |
| D3 | 1 | Schottky diode | B5817WS | - | https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_Yangzhou-Yangjie-Elec-Tech-B5817WS_C699102.html | |
| F1, F2 | 2 | 1.25A fuse 0603 | - | - | - | |
| P3 | 1 | SNES controller port | - | - | https://aliexpress.com/item/32828768824.html | |
| R1, R6, R8, R12 | 4 | 100kOhm 0603 | - | - | - | |
| R2, R3, R4, R5 | 4 | 330Ohm 0603 | - | - | - | |
| R7 | 1 | 270Ohm 0603 | - | - | - | |
| R9, R10 | 2 | 47Ohm 0603 | - | - | - | |
| R11 | 1 | 18kOhm 0603 | - | - | - | |
| R13 | 1 | 15Ohm 0603 | - | - | - | |
| R14 | 1 | 1kOhm 0603 | - | - | - | |
| U3 | 1 | 2.5V linear regulator | TLV71325PDBV | - | https://lcsc.com/product-detail/Linear-Voltage-Regulators-LDO_Texas-Instruments-TLV71325PDBVR_C90841.html | |
| S1 | 1 | Spartan Edge Accelerator | - | - | - | |
| - | 2 | 10-pin male header | Or generic, cut to size | https://lcsc.com/product-detail/Pin-Headers_XKB-Connectivity-X6511WV-10H-C30D60_C706882.html | ||
| - | 2 | 8-pin male header | Or generic, cut to size | https://lcsc.com/product-detail/Pin-Headers_XKB-Connectivity-X6511WV-08H-C30D60_C706880.html | ||
| - | 1 | 6-pin male header | Or generic, cut to size | https://lcsc.com/product-detail/Pin-Headers_XKB-Connectivity-X6511WV-06H-C30D60_C706878.html | ||
| - | 2 | 10-pin female header | Or generic, cut to size | https://lcsc.com/product-detail/Female-Headers_XKB-Connectivity-X6511FV-10-C85D32_C718235.html | ||
| - | 2 | 8-pin female header | Or generic, cut to size | https://lcsc.com/product-detail/Female-Headers_XKB-Connectivity-X6511FV-08-C85D32_C718237.html | ||
| - | 1 | 6-pin female header | Or generic, cut to size | https://lcsc.com/product-detail/Female-Headers_XKB-Connectivity-X6511FV-06-C85D32_C718239.html | ||
| Onboard Arduino Only | C26 | 1 | 0.1uF 0603 | - | Total 15 pieces including "Required" count | - |
| C18, C19 | 2 | 1uF 0603 | - | - | - | |
| C20, C27 | 2 | 10uF 0805 | - | Total 4 pieces including "Required" count | - | |
| C23, C30, C31, C32 | 4 | 0.1uF 0603 | - | Total 19 pieces including "Required" count | - | |
| C24, C25 | 2 | 18pF 0603 | - | - | - | |
| D2 | 1 | Schottky diode | B5817WS | Total 2 pieces including "Required" count | https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_Yangzhou-Yangjie-Elec-Tech-B5817WS_C699102.html | |
| D5 | 1 | Red LED 0603 | LTST-C191KRKT | Or generic | https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_Lite-On-LTST-C191KRKT_C125099.html | |
| D6 | 1 | Green LED 0603 | LTST-C191KGKT | Or generic, total 3 pieces including "Required" count | https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_Lite-On-LTST-C191KGKT_C125098.html | |
| F3 | 1 | 1.25A fuse 0603 | - | Total 3 pieces including "Required" count | - | |
| P4 | 1 | USB-C Port | U262-161N-4BVC11 | - | https://lcsc.com/product-detail/USB-Connectors_XKB-Connectivity-U262-161N-4BVC11_C319148.html | |
| P5 | 1 | 2x3-pin male header | X6521WV-2x03H-C30D60 | Or generic, cut to size | https://lcsc.com/product-detail/Pin-Headers_XKB-Connectivity-X6521WV-2x03H-C30D60_C706893.html | |
| R15, R16, R17 | 3 | 2.2kOhm 0603 | - | - | - | |
| R19 | 1 | 100kOhm 0603 | - | Total 5 pieces including "Required" count | - | |
| R22, R24 | 2 | 5.1kOhm 0603 | - | - | - | |
| R23, R25 | 2 | 1kOhm 0603 | - | Total 3 pieces including "Required" count | - | |
| SW1 | 1 | Pushbutton | TS-1101-C-W | - | https://lcsc.com/product-detail/Tactile-Switches_XKB-Connectivity-TS-1101-C-W_C318938.html | |
| U4 | 1 | Microcontroller | ATmega328P-AU | - | https://lcsc.com/product-detail/ATMEL-AVR_Microchip-Tech-ATMEGA328P-AU_C14877.html | |
| U5 | 1 | USB-to-serial IC | CH340C | - | https://lcsc.com/product-detail/USB-ICs_WCH-Jiangsu-Qin-Heng-CH340C_C84681.html | |
| Y1 | 1 | 16MHz crystal | Q24FA20H0023200 | - | https://lcsc.com/product-detail/Crystals_Seiko-Epson-Q24FA20H0023200_C255948.html | |
| External Arduino Only | A1 | 1 | Arduino Nano | - | - | - |
| - | 2 | 15-pin female header | B-2200S15P-A120 | Or generic, cut to size | https://lcsc.com/product-detail/Female-Headers_Ckmtw-Shenzhen-Cankemeng-B-2200S15P-A120_C124408.html | |
| Master Power Switch Only | C28, C29 | 2 | 1uF 0603 | - | Total 4 pieces including "Onboard Arduino" count | - |
| Q1 | 1 | P-Channel MOSFET SOT23 | PJM3415PSA | - | https://lcsc.com/product-detail/MOSFETs_PJSEMI-PJM3415PSA_C411717.html | |
| R20 | 1 | 100kOhm 0603 | - | Total 6 pieces including "Required" count | - | |
| R21 | 1 | 2.2kOhm 0603 | - | Total 4 pieces including "Onboard Arduino" count | - | |
| SW2 | 1 | Rocker Switch | RS601HL-1020011BB | Or use any switch of your choice | https://lcsc.com/product-detail/Rocker-Switches_HCTL-RS601HL-1020011BB_C2885783.html |
Refer to zwenergy's spartan-edge-esp32-boot repo for instructions on how to program the Spartan board's ESP32 (Use 01LoadDefaultBitstream). The ESP32 firmware allows the configuring of the FPGA logic from a bitstream file loaded on the microSD card.
Save one of the latest bitstream releases as /overlay/default.bit on your microSD card.
zwenergy's ESP32 firmware also supports uploading the bitstream file via WiFi, such that the microSD card doesn't need to be removed. Simply connect to the gbaHD network hosted by the ESP32 (default password is gbahdwifi, this can be modified by editing the ESP32 Arduino sketch), and navigate to http://gbahd.local/ (if this doesn't work, try 192.168.4.1 instead). From here, the web page allows you to upload a bitstream file directly to the microSD card. Bitstream changes are applied after power cycling the Spartan board.
If you assemble this board with an onboard Arduino, the ATmega328p will not come with the Arduino bootloader installed, so it will not be programmable from the Arduino IDE right out of the gate. Follow the official documentation to program the bootloader via the ICSP header on the board (follow the steps to program it as an Arduino Nano, a second Arduino is required).
Note that the onboard Arduino circuit is functionally identical to any Arduino Nano clone that uses a CH340 USB-to-Serial IC. If the microcontroller is not detected as a COM port on your computer, you may need to install the corresponding driver.
For advanced users who are familiar with programming microcontrollers via ICSP directly, the CH340C and USB-C port may be omitted entirely.
The Arduino is used to interface between the SNES controller port and the GBA for button inputs and the reset function. It also interfaces with the Spartan Edge Accelerator for on-screen display controls. Upload this sketch.
By default, the button combos are:
- L+R+X+Y to toggle the OSD
- L+R+START+SELECT to reset the GBA.
These combos can be configured by modifying the `define macros in the Arduino sketch.
As mentioned earlier, this is an optional feature that allows the use of an external toggle switch. This replaces the function of the power switch on the Spartan board itself, which would be inaccessible when installed in an enclosure. The load switch circuit (Q1, C28, C29, R20, R21) allows for the use of any toggle switch, regardless of rated current, and provides debouncing for poor/dirty switch contacts.
- Switch the power switch on the Spartan board to "EXTVIN-5V"
- Solder 2 wires from the legs of the power switch labelled "5V" and "USB" on the Spartan board to the corresponding solder points on the shield
- Solder 2 wires from the master power switch to the solder points labelled "POWER SWITCH" on the shield
- While the Spartan board is plugged into a USB-C power supply, the master power switch can be used to switch power on and off to the whole assembly
- Which way should the diodes be installed?
All the diodes on the board use KiCad built-in diode footprints, though admittedly they might not be the most clear. The silkscreen labels for the diodes indicate where the cathode is located:
- When using an EZ Flash Omega flash cart, the reset button combo will only reset the loaded ROM. Resetting to the flash cart menu after a ROM has already been loaded requires a manual power reset, or use the flash cart's own reset-to-menu function (L+R+START by default when enabled in the flash cart settings).
As always, thanks to the Gameboy Discord community for their continued support. Special thanks to zwenergy for his hard work on the gbaHD
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Feel free to modify this design however you like, but please make sure to give credit where it is due. I encourage you to share your improvements with the rest of the Gameboy modding community, I mainly frequent the Gameboy Discord and Subreddit
Under this license, you are not permitted to profit from or commercialize this design in any part without my express permission.