PARTS LIST

• 1 - PCB PCB

• 1 - Microcontroler U1 AVR128DA28

• 1 - Battery Holder BAT -

• 1 - Speaker SPK -

• 2 - Ceramic Capacitor C1, C2 0.1µf

• 2 - Ceramic Capacitor C3, C4 20pƒ

• 3 - Small Signal Diode D1, D2, D3 1N4148

• 1 - Zener Diode 3.3V D4 1N4728

• 1 - USB-MINI Female USB MINI -

• 2 - Resistor R1, R2 10KΩ

• 1 - Resistor R3 470Ω

• 1 - Resistor R4 82Ω

• 1 - Slide Switch Slide Switch DPDT

• 1 - Tactile switch 6x3 Right Angle RST -

• 1 - Quartz Crystal XTAL 32.768Khz

• 1 - Display conector 7 pin Male Header -

• 40 - Tactile switch 6x6x7.3mm Buttons 70gf

• 1 - Top Panel

• 1 - Bottom Panel

• 6 - M2 Bolt 6mm

• 6 - M2 Bolt 7mm

• 4 - M2 Brass post 5mm

• 2 - M2 Brass post 7mm

• 6 - M2 1mm plastic washer

• 1 - Blue Keycap

• 1 - Yellow Keycap

• 8 - Grey Keycaps

• 12 - White Keycaps

• 18 - Black Keycaps

• 1 - 3D printed bumper

• 2 - 3D printed Battery Holder

• 4 - Rubber feet

• 1 - LCD Display Module

• 1 - Display bezel

• 1 - USB to Serial Adaptor Cable  

Schematic

Download schematic.

Power

The PX-41CX can be powered either by a USB mini cable or a standard CR2032 coin battery.

Using a CR2032 battery form a reputable compay has a typical capacity of around 230mAh.

• Sleeping: less than 8µA (keeping the time and maintaining the ram)

• Idle: less than 35µA (display on)

• Running: 2mA @ 8Mhz to 6mA @ 32Mhz

Firmware Update

To udpate the firware you will need a serial to USB cable.
Set the RUN/FLASH slide swith to the FLASH position on the PX-41CX.

Requirements:
Python3 and libs from DXCore
prog.py script from DXCore

Create a new directory and name it tools.
Copy python3 and prog.py script into this directory.  

Run the command:
tools/python3/python3 -u tools/prog.py -t uart -u /dev/cu.usbserial-11110 -b 230400 -d avr128da28 --fuses 5:0b11001001 6:0x04 7:0x00 8:0x00 -f px41cx.hex -a write -v

Replace /dev/cu.usbserial-11110 with the actual serial port of your PX-41CX. Replace px41cx.hex with the filename of the new firmware you want to upload.