SummerCart64/docs/06_build_guide.md
2024-05-05 16:15:26 +02:00

7.3 KiB


Step by step guide how to make SC64

All necessary manufacturing files are packaged in every sc64-extra-{version}.zip file in GitHub releases. Please download latest release before proceeding with the instructions.


PCB manufacturing data

  1. Locate KiCad project inside hw/pcb folder
  2. Export gerber/drill files
  3. Export BOM spreadsheet
  4. Export PnP placement files
  5. Send appropriate files to the PCB manufacturer

PCB requirements

Before ordering PCBs make sure you select correct options listed below:

  • PCB thickness: 1.2 mm
  • Surface finish (plating): ENIG (Hard gold for edge connector is recommended but it's very expensive)
  • PCB contains edge connector: yes
  • Beveled edge connector: yes, 45° (other angles also should work OK)

Components

  1. Locate interactive BOM file inside hw/pcb folder (alternatively, check out this BOM discussion)
  2. Order all parts listed in the BOM file or use PCB assembly service together with your PCB order

Plastic shell

  1. Locate .stl files inside hw/shell folder
  2. Use these files in the slicer and 3D printer of your choice or order ready made prints from 3D printing company
  3. For screws, M2x10 works great for the top two holes while M2x8 fits well in the bottom two

Putting it together

There are no special requirements for soldering components to board. All chips and connectors can be soldered with standard manual soldering iron, although hot air station is recommended. Interactive BOM has every component and its value highlighted on PCB drawings and it's strongly recommended to use during assembly process. You can skip this step if PCB assembly service was used in previous steps.


Initial programming

Please read the following instructions carefully before proceeding with programming.

Note: This guide assumes you are using Windows 10 or above.

You will require the following hardware:

  • A PC running Windows 10 or above (any Linux distro should also work but programming FT232H EEPROM is arguably trickier without an official app).
  • A USB to UART (serial) adapter (with 3.3V signaling is required, e.g. TTL-232R-3V3).

You will require the following applications and packages:

  • FT_PROG - FTDI FT232H EEPROM programming software.
  • Python 3 with pip3 - necessary for initial programming script: primer.py (Windows install: check option add python to PATH).
  • sc64-extra-{version}.zip - programming scripts and firmware files, download the latest version.

Programming must be done in specific order for primer.py script to work correctly.

Preparations:

  1. Install FT_PROG.
  2. Install Python 3.
  3. Unpack sc64-extra-{version}.zip into a folder.
  4. Open terminal and navigate to the folder you've unpacked SC64 files.

First, program the FT232H EEPROM:

  1. Connect the SC64 board to your PC with a USB-C cable.
  2. Locate FT232H EEPROM template ft232h_config.xml from the fw/ftdi/ directory.
  3. Launch FT_PROG software.
  4. Click on Scan and parse if no device has shown up.
  5. Right click on SC64 device and choose Apply Template -> From File.
  6. Select previously located ft232h_config.xml.
  7. Right click on SC64 device and choose Program Device.

Your SC64 should be ready for next programming step.

Second, program FPGA, microcontroller and bootloader:

  1. Disconnect SC64 board from power (unplug USB-C cable).
  2. Connect serial UART/TTL adapter to TX/RX/GND pads marked on the PCB. Cross connection TX -> RX, RX -> TX!
  3. Connect serial adapter to the PC.
  4. Check in device manager which port number COMx is assigned to serial adapter.
  5. Connect SC64 board to the PC with USB-C cable (IMPORTANT: connect it to the same computer as serial adapter).
  6. Locate primer.py script in the root folder.
  7. Make sure these files are located in the same folder as primer.py script: requirements.txt, sc64-firmware-{version}.bin.
  8. Run pip3 install -r requirements.txt in the terminal to install required python packages.
  9. Run python3 primer.py COMx sc64-firmware-{version}.bin (replace COMx with port located in step 4). On Windows it's python instead of python3.
  10. Follow the instructions on the screen.
  11. Wait until programming process has finished (DO NOT STOP PROGRAMMING PROCESS OR DISCONNECT SC64 BOARD FROM PC, doing so might irrecoverably break programming through UART header and you would need to program FPGA and/or microcontroller with separate dedicated programming interfaces through Tag-Connect connector on the PCB).

Congratulations! Your SC64 flashcart should be ready for use!


Troubleshooting

primer.py threw No SC64 USB device found error

This issue can be attributed to incorrectly programmed FT232H EEPROM in the first programming step. Check again in FT_PROG application if device was configured properly. Make sure default FTDI drivers are installed for the SC64 in the device manager (only on Windows OS). Make sure you have correct access to /dev/ttyUSBx device and ftdi_sio and usbserial modules are loaded (only on Linux OS).

primer.py threw SDRAM test error... message

This issue shows up when there's a problem with the connection to the SDRAM chip or the chip itself is malfunctioning. Check for any solder bridges and unconnected pins on U8/U9 chips. Once FPGA and microcontroller has been programmed successfully primer.py script needs to be run in special mode. Please use command python3 primer.py COMx sc64-firmware-{version}.bin --bootloader-only to test SDRAM again and continue bootloader programming process.

primer.py threw other error message

Due to multiple possible causes of the problem it's best to start visually inspecting SC64's board for any defects, like bad solder work or chips soldered backwards. If visual inspection didn't yield any obvious culprits then next step would be to check if everything is connected correctly. Check if TX/RX signals aren't swapped and if SC64 is getting power from the USB cable. Best place to check supply voltage are the exposed test pads on the left of U8 chip. If everything at this point was checked and looked fine, then feel free to open new thread in the Discussions tab. Make sure to describe your problem extensively, attach SC64 board photos from the both sides, and paste all logs/screenshots from the primer.py output.