[BREAKGLASS] Design files for the SeedHammer II hardware.
https://seedhammer.com
5cbffd00ce
When the external USB PD supply power cycles the board, we keep the MCU and LCD powered for a few seconds with charge from the capacitor bank. However, the 2 MOSFETs acting as level shifters for USB PD I2C communication leaks voltage of ~1V to the I2C ports of the USB PD controller, which leaks through to VBUS. Some supplies refuse to complete the power cycle as long as there is any residual voltage on VBUS. Replace the MOSFETs with a PCA9306 I2C level shifter. It allows the USB PD I2C and thus VBUS voltage to drop to ~0V. |
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| cad | ||
| pcb | ||
| specs | ||
| .gitignore | ||
| go.mod | ||
| LICENSE | ||
| README.md | ||
SeedHammer II hardware
This repository contains the design files for the SeedHammer II machine.
PCB
The schematic and PCB are in KiCad format.
Generate production files (gerber, BOM, CPL) with the Go script:
$ cd pcb
$ PATH=$PATH:/path/to/kicad-cli go run .
Production boards are manufactured by JLCPCB with the following settings:
- Surface Finish: ENIG
- Material Type: FR4 TG155
- Stackup: JLC04161H-7628 (impedance controlled)
LCD
The LCD is a ER-TFT035IPS-6 with capacitive touch from buydisplay.com. The variant with resistive touch is not supported by the firmware.
CAD
The CAD files for the custom machine parts are in STEP format.