Shared Projects by dewhisna

Inline board to connect between USBasp in-system programmer and the target board. It provides LED light feedback for host boards lacking LEDs and has a reset button and a jumper for doing special diagnostics on the host board when the hosts firmware supports it.

V2 Update to the Original I2C Character Display CPU Board. Identical to the I2C Character Display CPU V2 but with a reversed connector for the display. This is designed for OLED display modules that generally have their connector on the top edge of the PCB, whereas the original non-reversed version is for the ones with the connector on the side edge of the PCB. Otherwise, the two circuits are identical.

V2 Update to the Original I2C Character Display CPU Board. This board goes inline between a host CPU and an OLED (or similar) I2C/SPI graphical display. Its purpose is to convert the graphical display into a character-based display, removing the overhead of font rendering and pixel transfer over the slow I2C bus from the host.

Note that the CPU here is the ATmega328PB (PB version) with dual I2C ports. 12 MHz was chosen for the ceramic resonator, instead of 16MHz or 20 MHz, so that it will run at 3.3v within the specs given in the datasheet. You may, however, be able to overclock it successfully, especially if running at 5v. Be careful, however, of OLED displays with very noisy voltage inverters, as they will interfere with CPU overclocking. I managed to brick two ATmega328PB CPUs trying to run one with this board at 20MHz. 16MHz, however, was no problem.

An identical board with a reversed display connector is also available.

V2 Additions/Changes:

• Support for SPI communications with the display in addition to I2C

• Support for CPU Driven Reset Line to the display

• Support for either display driven or CPU driven I2C address (DC pin) option

• Ferrite bead on display power to reduce noise from the display’s power inverter

See also the Updated V2 version of this board which provides SPI display mode support as well.

Identical to the I2C Character Display CPU V1 but with a reversed connector for the display. This is designed for OLED display modules that generally have their connector on the top edge of the PCB, whereas the original non-reversed version is for the ones with the connector on the side edge of the PCB. Otherwise, the two circuits are identical.

This is the User-Interface board for the FPGA DRSSTC Interrupter V2. It provides the potentiometer and keypad inputs, plus adds status lights, etc. This method was easier to manage than the individual dangling components in the first version.