Parts and Datasheets


This is the brain and heart of our calculator. This chip combines an ARMv7-M Cortex-M7 core clocked at 216 MHz and 256K of Static RAM.

Download the STM32F730 datasheet - 193 pages, 2.0 MB
Download the STM32F730 reference manual - 1142 pages, 9.9 MB

Flash memory

This is the persistant memory of our calculator. This chip stores 64 Mbit of data, and serves it over a 104 MHz Quad-SPI bus.

Download the AT25SF641 Flash memory datasheet — 80 pages, 6.3 MB

Display controller

The LCD panel integrates an LCD controller that receives bitmap data from the MCU and drives the pixel matrix accordingly. This LCD controller has an integrated SRAM framebuffer and is driven using a 16-bit wide bus.

Download the ST7789V TFT-LCD controller datasheet — 308 pages, 8.3 MB

Logic power supply

This part regulates the voltage from the Lithium-Polymer battery. It's a low-dropout regulator that takes any voltage between 3.0V and 5.5V and outputs a constant 2.8V. Its efficiency depends on the voltage gap and is fixed by the fact that the input current is equal to the output current.

Download the RT9078 low-dropout regulator datasheet — 193 pages, 2.0 MB

USB battery charger

Our Lithium-Polymer battery is recharged over USB. This chips draws current from the USB port and charges the lithium cell, using a CC-CV (constant current, constant voltage) charging curve.

Download the RT9526A lithium battery charger datasheet — 13 pages, 270 KB


This surface-mounted component includes three LEDs (red, green and blue) in a small package. These LEDs are able to shine any color through the casing of the device.

Download the LTST-S310F2KT side-looking RGB LED datasheet — 14 pages, 1.9 MB

ESD USB protection

The USB port can receive electrostatic discharges. Those very high voltage surge can permanently damage electronic components. This part evacuates the surge entering from the USB port and protects the whole circuit.

Download the ST-USBLC6 ESD protection datasheet — 14 pages, 275 KB

Flash memoryAT25SF641
Display controllerST7789V
Logic power supplyRT9078
USB battery chargerRT9526A