Any use of this project is under your own responsibility. You will be responsible of checking the correct construction and functionality of your board. By using this project You will agree that I cannot be held responsible if it will destroy any of your devices, damage your computer, burn down your house or whatever.
I want to stress this out: You're on your own using this. It works for me, I cannot give guarantees to you. Also, do not go bother the Lava RSC people about it for support!!!
The Lava RSC is a family of very nice Famiclones that use ICs found in the original Famicom, complemented with an FPGA used to output an analog RGB picture.
From time to time, the people at Lava update the FPGA firmware to fix bugs and add new features. The high end model, the Lava RSC, includes an SD card slot connected to an MCU, and is capable of updating the FPGA autonomously, while the Lite version requires an FPGA programmer and not-so-easy to obtain Anlogic software to complete the update.
This board reproduces the upgrade circuitry found in a Lava RSC, but as an external module. This way it's sufficient to install headers on your Lite motherboard (there are well marked spots to solder one), if you want, bring out the signals via a flat cable, and connect this adapter when you want to perform the update. The rest works the same as the original Lava RSC (beside requiring a Lite-specific firmware, of course).
You can order the board for this project at PCBWay and support me or download the gerbers and have them printed wherever you like!!!
The board was designed with KiCad EDA.
This board uses mostly SMD components, but the footprint allows for handsoldering.
| Component | Qty | Type / Value | Notes |
|---|---|---|---|
| R3, R7, R8 | 1 | 10K 0805 resistor | |
| R6 | 1 | 1K 0805 resistor | |
| RN1, RN2 | 2 | 4-resistor array 4x0612 (1206) | Convex package, the resistors are isolated |
| C2, C3 | 2 | 22pF 10V C0G 0805 capacitors | |
| C1, C5, C6-C9 | 6 | 100nF 10V 0805 capacitors | |
| C4, C10 | 2 | 10uF 10V 0805 capacitors | |
| J3 | 1 | 4pin header, 2.54mm | |
| J4 | 1 | 6pin header, 2.54mm | I prefer using angled ones for this |
| XS1 | 1 | uSD connector | You can find compatible ones on AliExpress |
| Y1 | 1 | 8Mhz crystal, HC-49SD | |
| U1 | 1 | STM32F103C8T6, LQFP-48 | A compatible GD32F103C8T6 has been tested and found to be working |
In this repository you'll the firmware file McuFirmware_dump.hex dumped from my Lava RSC: it will search for a file named LavaRSC.aje in the root
of a FAT32 formatted SD card.
You can use an st-link (a clone is fine) to flash this board via the SWD header (J3). Remember to power the board with 3.3V.
You can use the st-flash utility to program the device:
st-flash --format ihex write .\McuFirmware_dump.hex
or use the STM32 ST-Link Utility software.
- Format an SD card to FAT32, make sure it is empty and copy the update files in it (with name
LavaRSC.aje). You'll find a Lite compatible firmware in this repository, equivalent to the Lava RSC firmware 1.7 - Plug the SD card in the update board
- Wire the JTAG connector (J4) to the points of the same name on your Lite motherboard. Dupont wires are ok for this
- Remove any cart inserted in the Lite
- If connected, remove any wire connected to the SWD header on the upgrade board
- Power on the Lite. After a few seconds, the LED on the upgrade board should start flashing
- Wait until the LED stops flashing and remains on
- Power off the Lite and remove the upgrade board
- Done