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Shervin Emami
964 followers -
The journey IS the destination!
The journey IS the destination!

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Ultra low cost Linux development board. Not based on Arm, but a Chinese DVB-S2 SoC with their own C-SKY instruction set, which happens to have made it to the mainline kernel recently.
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Howto make a $35 Raspberry Pi 3B+ a blazingly fast computer!

U.S. industry s tricky: "Intel givet, Microsoft taket". Since two decades or so, nothing really runs faster. Neither desktop programs nor databases. Instead, memory footprint explodes (see .NET and Java) without visible major performance inprovements.

MySQL hardly comes over 5,000-10,000 inserts/updates per second, almost independent of engine used. For a single SQL insert multiple IO operations on disk are neccessary. That's called 'write amplification'.

Interestingly, there are a couple of new algorithms out there, which keep # of writes/insert factor low. "MVCC", "append only" for database file itself as well as "append only b-tree" here keep number of disk writes low.

LMDB (Lightning DB also see OpenLDAP), Redis, Sophia (http://sophia.systems) are databases, which are extremely fast, even on a cheap $35 Raspberry Pi hardware.

With these on e.g. tested Crucial SSD you easily outperform any Intel hardware with MySQL.

Note: USB 2.0 already is 480MBit ... saturating 2 x 100 MBit networks is no problem for that mini computer.

My urgent advice: Keep away from U.S. "Wintel (Oracle) alliance" and especially Apache Foundation software!!! (U.S. industry knows, why they're sponsoring!!!)

Have fun!
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Howto write your own spreadsheet in pure Python!

Here two examples, one for Cloud and one written with WxWidgets library. Both run on Ubuntu, Windows, Mac OS X ...

It's rather ridiculous to see, how few lines of Python are needed to get Excel or LibreOffice Calc - like functionality.

The clou here is, that Python already is an interpreter, where a2=(a1*sin(a3)) is a legal Python expression. All you then need to do is to build a dependency graph (100 lines!) for executing these "cells", handle recursion.

The cloud example: https://youtu.be/BbsdFGo6SzY
Source: https://github.com/pythonanywhere/dirigible-spreadsheet/

The desktop version: https://manns.github.io/pyspread/

Most impressive is, that you can directly bind e.g. NVIDIA GPU accelerated TensorFlow into your Python spreadsheet. No APIs or other "glue" neccessary!

Have fun!
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The USD$2 Air602 Wifi module is even cheaper & smaller than ESP8266! It doesn't have the massive developer community that ESP8266 has, so I'd stick with ESP8266 for now. But this chip uses an ARM Cortex-M3 CPU, so it has potential to eventually turn into an even more developer friendly board one day! Meanwhile, you can buy an ESP32 for just USD$3 now!
https://www.seeedstudio.com/Air602-WiFi-Module-p-3139.html
Air602 WiFi Module
Air602 WiFi Module
seeedstudio.com
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Hackaday posted an article about my wireless hand-held keyboard/mouse alternative
Do you have a pressing need to type with one hand? We've got the perfect project for you, and it also strengthens your forearm!

The Ergonomic Handheld Mouse / Keyboard Alternative from [Shervin Emami] is an all-in-one solution for your keyboarding and cursor moving needs.
The core of this build is a ‘grip-strengthening’ device that’s sold to guitarists. While the actual benefit of…
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This looks pretty amazing: Generating component diagrams directly from the datasheet!
Tired of creating schematic symbols yourself in KiCAD? Try uConfig!

Last time we talked about a KiCAD tool it was to describe a way to make the zen-like task of manual assembly more convenient. But what about that most onerous of EE CAD tasks, part creation? Home makers probably don’t have access to expensive part library…
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This sounds great for hobbyists that aren't ready to buy an oscilloscope! 20kHz bandwidth is ultra slow compared to a normal >100MHz oscilloscope, but it's still about 20,000 times faster than a regular multimeter that runs at around 1Hz!
New 2-in-1 digital multimeter + oscilloscope selling for ~$42 shipped for a limited time
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