Articles about raspberry pi: here SN74HC595 shift register. Controlling from Raspberry: here Comparison of Polou DC motor drivers Comparison of stepper motor drivers DC motors Pololu DRV8833 Dual Motor Driver Carrier exp-tech 4,95€ two DC motors or one stepper motor 2.7–10.8 V 1.2 A continuous (2 A peak) per motor Motor outputs can be paralleled to deliver 2.4 A continuous (4 A peak) to a single motor Reverse-voltage protection circuit...
For other links about raspberry pi go here Pinouts How to control It seems that procedure described in Texas Instruments’ datasheet is wrong: Using in motor shield DK Electronics V1 Scheme: L293x Quadruple Half-H Driver (pdf) Connection Raspberry PIN 6 -> Shield GROUND Raspberry PIN 11 -> Shield PIN 8 (Register PIN 14, SER / DS) Raspberry PIN 12 -> Shield PIN 12 (Register PIN 12, SRCLK / SHCP) Raspberry PIN 13 -> Shield PIN 4 (Register PIN 11, RCLK / STCP)...
Source here Install devilspie: sudo apt-get install devilspie There is also a gui called gdevilspie, but the rules it produced seemed inaccurate and often didn’t quite work, so it is easiest to concoct a rule by reading the readme and the manpage. How the rule was created All rules created must go in ~/.devilspie, and have a .ds extension, so firstly create the folder if it doesn’t exist with mkdir ~/....
Create more secure ssh keys Create a key using elliptic curve cryptography (more secure): ssh-keygen -a 100 -t ed25519 generate RSA key of length 4096 to file my_key ssh-keygen -t rsa -b 4096 -C "your@e-mail.com" -f my_key Generate md5 fingerprint of the key (works in newer ubuntu, 16): ssh-keygen -lf ./my_key -E md5 see also: Upgrade Your SSH Key to Ed25519 How to prevent SSH from scanning all the keys in ....
How you can take an OpenVPN .ovpn config file and extract the certificates/keys Copy from between <ca> tags into ca.crt, remove <ca> tags from original file. Copy from between <cert> tags into client.crt, remove <cert> tags. Copy from between <key> tags into client.key, remove <key> tags. Copy from between <tls-auth> tags into ta.key, remove <tls-auth> tags. Remove the line “key-direction 1” Above "# -----BEGIN RSA SIGNATURE-----" insert the following lines. ca ca....
Running some GUI application as another user: user1@laptop:~$ su - user2 user2@laptop:~$ leafpad ~/somefile.txt No protocol specified The problem is user2 doesn’t have access to your screen. Solution: xhost + Probably not the safest one. Source: thread
Let’s consider how python standard unittest module suppose to use mocks. Assume we want to test a method that creates and uses objects of other classes: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 # content of module.py # classes that we want to mock class ClassName1: pass class ClassName2: pass # class that we want to test class ProductionClass: def foo(self, parameter1, parameter2): object1 = module....
ParaDISE - Parallel Distributed Image Search Engine. Based on Hadoop, probably offline processing. Image Similarity service (github) - scala based image similarity service, declared to be scalable. Image storage and image similarity logic is implemented within independent, stateless micro-services. Data is stored in postgres. Clustering is based on histograms. 1 contributor. No tests. abandoned. ViSense SDK for python - SDK for closed source image search List of Content-based image retrieval (CBIR) engines (wikipedia)...
Twelve factor app Modules vs Microservices About reasonable choice for architecture To read: Best Practices for Building a Microservice Architecture События, шины и интеграция данных в непростом мире микросервисов Spring Nice tutorials about Spring For example How To Do @Async in Spring
Commands List indexes curl -X GET localhost:9200/_cat/indices Delete index curl -X DELETE localhost:9200/YOUR_INDEX Delete all indices curl -X GET localhost:9200/_all List of all doc_types in a given index curl -X GET localhost:9200/YOUR_INDEX/_mapping | jq ".YOUR_INDEX.mappings | to_entries | .[].key" Running elastic seach with a limited memory #!/bin/sh ES_JAVA_OPTS="-Xms1g -Xmx1g" ./elasticsearch