ISO232 - Optically isolated USB to RS232 interface

ISO232 A00RS232 are still very popular to control legacy equipment. In industrial settings with long cable runs, interference and different ground references it is necessary to have galvanic isolation. ISO232 is a simple implementation using the FTDI FT230X and opto isolators that can reach speeds up to 115200baud.


The schematics is divided in four main portions.

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GRAND - 6Mbps USB True Random Number Generator

GRANDA good random numbers generator is fundamental to ensure the security of many modern data encryption algorithms. Depending on the workload, the entropy collected automatically by the kernel might not be sufficient to generate the random numbers at the requested rate. In these cases an external entropy source can greatly improve performance. GRAND is a USB TRNG (True Random Number Generator) based on the ST Microelectronics STM32.

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M10MEM - 8KB SRAM Module for Tandy Model 100

M10MEMBeing nostalgic for the birth of laptop computers we recently acquired an Olivetti M10. The M10, like many of the KC-85 derivatives like the Tandy TRS-80 Model 100 and the NEC PC8201A, uses custom modules for their system RAM. These modules contained four 2Kx8 SMD SRAMS mounted on a ceramic substrate with a non standard DIP footprint. Needless to say, these modules have become increasingly hard to find. M10MEM is a modern replacement for the memory modules using 8Kx8 SRAMS.

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GZ/80 - Zilog Z80 turbo card for Apple II computers

gz80The Microsoft Softcard was the first card to allow CP/M software to run on the Apple II. It was originally developed to simplify the porting of Microsoft Basic to the Apple II. It turned out to be a great success and at some point in time it was the most popular CP/M platform in use.
This success prompted the development of many compatible cards. Some exact copies, some enhanced or cost reduced. The GZ/80 is a modern implementation of a Softcard compatible card with an additional turbo mode with approximately double the speed of the original card.

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Happy 2021!

world map2020 was a very unusual year. The COVID-19 pandemic has disrupted many people's life and unfortunately is still ravaging the world. We sincerely hope that 2021 will bring an end to the pandemic and we would like to wish all our customers, friends and suppliers a happy new year. We are very thankful for all the support we received so far and hope to continue in 2021.

GRAD - Micropower Geiger-Müller Counter Arduino Shield

GRAD A01Like many other hobbyist we have always been fascinated by radioactivity and the sensors to detect it. Geiger-Müller tubes are a common and relatively inexpensive way to measure radiation. GRAD is a complete solution for radiation counting in an Arduino shield form factor. Its main features are dual tube support to increase sensitivity and very low power consumption.

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NUPS - MCU UPS with NiMH Batteries

NUPS A00Many MCU applications are portable and need a mean to provide power on the go. There are many solution based on Li-ION and Li-Polymer batteries. However Lithium chemistries need sophisticated charging and protection circuits to avoid dangerous situations. For lower power projects NiMH batteries provide a simpler and safer alternative. NUPS (NiMH UPS) can provide 3.3V and 5V using 1 to 3 AA or AAA NiMH cells.

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ISO01 - Compact low voltage isolated power supply

ISO01 A00While working in the lab it's often useful to have a small isolated power supply handy. Depending on the circuit configuration, ISO01 can generate galvanically isolated unipolar and symmetric voltages from a single 3.3V or 5V rail. The circuit is based on the Texas Instruments SN6501 transformer driver and uses an easy to obtain off the shelf transformer.

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GZ/80S - 20MHz Z-80 PCPI Applicard compatible Apple CP/M card

GZ80 B00The PCPI Appli-Card was the first single board computer style CP/M card for the apple II. It featured a 6MHz Z-80 CPU paired with 64KB of RAM and 2KB of ROM. Thanks to the high clock and zero wait states DRAM accesses the card performed almost 3 times as fast as the Microsoft SoftCard. The GZ/80-B00 is a new implementation of the PCPI card with a 20MHz Z-80 CPU and 512KB of static RAM.

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EFM8 Flash - Multi platform GUI Flash tool for Silicon labs EFM8UB1 USB MCUs

EFM8 Flash LinuxSilicon Labs makes many excellent 8051 based MCUs. All the MCUs in the EFM8UB line have a native USB and are pre-programmed with a USB HID bootloader. EFM8 Flash is a small GUI tool to flash the MCU from a binary file. The program uses the wxwidgets toolkit for a native look in all supported operating systems and hidapi for cross platform compatibility.

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