If you want to get the block header of the latest block generated on the bitcoin blockchain using bitcoin-cli it’s a little tricky (and hard to say!). You need to first find the latest block number (height), then find the hash of that block and then get the header using the hash. Since the getblockheader […]
Author archives: Bob Peers
IoT with Node-RED and Python
Now I have two Raspberry Pis running, one as a Bitcoin full node and the other mostly used as a dev/experimentation machine I decided it’s time to put the dev machine to some use. I’d also like to learn more about IoT (Internet of Things) and how they are wired together and communicate so this […]
Introduction to Image Classification using UiPath and Python
After my previous post showing image classification using UiPath and Python generated many questions about how to implement the same I decided to expand upon the theme and give a more detailed description about how to achieve this. My starting point was thinking how I might integrate UiPath with python now that it’s integrated within the platform. I find […]
How to use Amazon S3 from Node-RED
Amazon S3 (Simple Storage Service) is a very commonly used object storage solution that’s cheap to use and highly reliable. Think of it as a file system in the cloud with enterprise features that you can use to store almost anything. Amazon S3 This guide assumes you already have a working Amazon S3 account and […]
Linux Command Line Calendar
I’ve used Linux for almost 20 years and somehow never knew you could get a calendar on the command line 🤯🤯 Just type ‘cal’ for the current month or cal followed by the year (‘cal 2019’ for example) to get a full year. See the man pages for details. me@myserver:~$ cal 2019 2019 January February […]
Bitcoin RPC Commands over SSH Tunnel
If you’re running a Bitcoin full node and want to run RPC commands against the Bitcoin client from a remote machine the easiest and safest way to do this is using Port Forwarding over an SSH connection. What is Port Forwarding used for? Secure access to a port that is otherwise not listening on a […]
Generating New Product Names using Neural Networks
So everyone knows Machine Learning / Artificial Intelligence / Cognitive Computing, call it what you will, is the new marketing catchphrase for people trying to sell their software products and services. You can be sure if it’s not already baked in then it’s in the roadmap for 2020. It used to be ‘Big Data’, but […]
Getting Database and Table Sizes in Postgres
Total Database Size This SQL simply gets the total size of the database in a human readable format. SELECT pg_size_pretty(pg_database_size(‘postgres’)) as db_size List all Tables This lists all the tables in the database public schema. SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname = ‘public’ Search Schema for Column Name I often need to search all the […]
Pretend Money
In light of today’s news on the European Central Bank restarting the money printers only 9 months after they turned them off. File under funny but true.
Setting Up a Local Blockchain with Ganache
Why would I want to do this? Interacting with Blockchains and blockchain technology probably seems for most people like a very complex task. How to even get started? Don’t they run on some servers spread across the globe? How would I make a transaction and see the result? Wouldn’t I use to use real money […]