Systems Archives - Jacob N Calvert

Why the Alinco DR-735T can’t transmit at 9600bps

March 7, 2021

The Alinco DR-735T is a very capable, dual band, dual VFO, full duplex, cross-band repeat capable radio, with an industry standard mini DIN TNC connector on the back for working packet. While I was reading about the capabilities of this radio in its manual, I noticed that it can received 9600bps packet radio, but can only transmit up to 4800bps. The reason why was not intuitively obvious to me upon first glance at the radio’s specifications, so I went deeper…

Virtualization for Embedded Systems Series: Type-2 Hypervisors Deep Dive

March 23, 2020

Jacob

Series, Systems, Virtualization

In the previous post in this series, we dove deep into container technology and looked at how to implement some functionality into containers applicable to embedded devices. In this post, we will look at type-2 hypervisors and dive deep into practical ways to use them for embedded systems. This post will be light on content as I am quite busy currently, but wanted to wrap up this series. I will try to circle back and dive deeper into this topic…

Better JTAG on the Cheap with the FT232H

March 5, 2020

Jacob

Build Your Own, Programming, Projects, Systems, Testing

A couple of weeks ago I wrote a post about using the FTDI FT232R as a cheap JTAG debugger. I’ve been using it for a bit now to play with my Raspberry Pi 3B, and now that my code size has grown, the FT232R is just too slow to cut it. Here’s a breakdown: on the FT232R, the max speed I can set the adapter to is 3MHz. This has given me a transfer speed (loading via GDB) of around…

Virtualization for Embedded Systems Series: Containers Deep Dive

November 18, 2019

Jacob

Series, Systems, Virtualization

In the previous post, I looked at several real-world use cases for containers and hypervisors. This post will be a deep dive into containers and a how-to on using them. Note: all the code, Dockerfiles, etc. are archived in a git repo at GitHub. Container History Origins A little history is needed before we jump into building and deploying containers. Docker, which is likely still the largest container technology provider by a longshot, was originally released in 2013. In just…

Hacking a Smart Outlet

November 17, 2019

Jacob

Programming, Projects, Systems

IoT Everywhere Everything, and I mean everything is “smart” these days. Everyone has heard of the Internet of Things, and we are living through the emergence of some incredibly revolutionary connectivity. Some pretty cool and useful concepts have come out of it, admittedly, but there’s also some drawbacks. I really enjoy the idea of having smart outlets that I can command with my voice, and there are outlets-a-plenty on Amazon, but can I trust them? I’ve decided to use my…

Multicore Processor Modes of Operation

November 5, 2019

Jacob

Systems

Multicore processors were first introduced in the early 2000’s, and were pervasive in common computing platforms by the 2010’s. The industry started with dual core chips, and then quad core, and now we are up to 48 cores! When the hardware industry brought multicore chips to fruition, the software community had to invent new ways to utilize those additional cores. I’d like to use this post to discuss a few of the common multicore software utilization schemes or modes and…

Better Systems Management Through COTS Technology

April 16, 2018

Jacob

Systems

The concept of computing has been around almost as long as the mathematics from which it derives its usefulness. The world of computing as we know it today only began in the last century or so, and really only since the invention of the bipolar transistor. Fast-forward to the modern era of computing wherein we have unfathomable computing power surrounding us daily. Computing platforms and the related technology is driving advancement in every industry across the globe. From research to…