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Category: Research and Development

Scheduled vs Supervised Tasks

Scheduled vs Supervised Tasks

Scheduling tasks in Linux is traditionally done with the Cron Task Scheduler.  There are many online resources about cron, one of which is this site, https://www.vultr.com/docs/how-to-use-the-cron-task-scheduler/.  With Webmin, the task scheduling can be managed through the WebUI.  Details can be found here, https://doxfer.webmin.com/Webmin/Scheduled_Cron_Jobs.   Here is a simple scheduled task that reboots the Linux host daily at 1:30am. 30 1 * * * systemctl reboot -i Scheduling this in Cron or through Webmin results in the same entry in the respective…

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MicroSD Backups with Encryption that Save Space

MicroSD Backups with Encryption that Save Space

This post will cover steps on how to create and secure MicroSD backups, with the focus being on disaster recovery for RPi systems.  This method of backup is hardly the best method available, but it does offer space savings and more security.  In this demonstration, a second Linux system will be used as the backup target with the MicroSD media attached as the backup source. First step is to establish how large the MicroSD media is and if the target…

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Visualizing Data with Processing

Visualizing Data with Processing

The purpose of this post is to demonstrate how to use Processing to present data in a visual way. The methods used in this post will be based on the work done by M.Furkan Bahat. Source – https://mfurkanbahat.blogspot.com/2014/11/artificial-horizon-and-compass-using.html The hardware used in this demonstration will be the following: GY-521 MPU6050 Arduino Uno ESP32-Cam ESP32-USB-Module Patch wiring USB cables Windows 10 laptop The MPU6050 is connected to the Arduino Uno using the following pin connections, as shown in the images below….

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Python Data Visualization

Python Data Visualization

In an earlier post, python was used to generate an image from datasets. That method lacked the full features needed to create a final image. This post will introduce Plotly as a preferred method. It offers more options and is targeted for use as a tool for dataset visualization. First we’ll need a dataset that is tangible. In this post the dataset will be generated from a field scan to create an image array. The device used to scan the…

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FlySky iBus Interface

FlySky iBus Interface

The FlySky TX has some interesting features that allow it to display sensor readings from a RX. Having a ground based data logger made looking into this worthwhile. This post will cover the process used by the FlySky for sensor readings as well as interfacing micro controllers as a sensor source. There is a community of developers that have done a bulk of the work presented here and an effort will be made to give credit to them. The FlySky…

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FlySky RSSI Telemetry

FlySky RSSI Telemetry

RSSI, which stands for received signal strength indication, was covered in the last post. The topic covered how the Nordic Seminconductor’s nRF240L0 wireless device could be used to measure RSSI values. Those values reveal the reliability of the radio controlled reception and interference that might be present. RSSI telemetry is basically a tool to see invisible radio waves that operate on the same operating frequency as the radio controller (TX) and receiver (RX). FlySky is a manufacturer based out of…

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RSSI Interference

RSSI Interference

Before diving right in on this topic, we should ask what is RSSI and why does interference matter. First off, RSSI stands for Received Signal Strength Indicator and it’s a measurement of the radio frequency power level present at the receiver (1 and 2). A radio frequency transmitter typically has a fixed power output level. As a receiver moves away or around the transmitter, the received power level varies. RSSI is a way to measure that variation. Typically the variation…

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Modified Volantex Ranger 600 Controller

Modified Volantex Ranger 600 Controller

The stock Volantex Ranger 600 TX is as basic as any TX can get. The undocumented throw reversals prompted a closer look at the controller. The terms controller and TX apply to the hand held radio controller used to operate the remote controlled plane, TX will be used going forward. One item that was replaced with a yellow LED was the beep indicator. Since a lot of bench testing was going to take place, the blinking LED would be less…

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ESP-32 Flight Datalogger – Thrown off

ESP-32 Flight Datalogger – Thrown off

With a couple of flights done successfully, it was time to go back to the location where the earlier plane Bryce was lost. The area seemed to have something that may have influenced the loss, in addition to other factors. The park is rather small, so anyone walking on the field was a no go. With the occasional walker, the park was clear. The ESP32-Cam system was activated to get a GPS lock, while the routine of preflight was done….

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ESP-32 Flight Datalogger – Rise Above It

ESP-32 Flight Datalogger – Rise Above It

The data gathered from the flights revealed some interesting things. The first was that the amount of detected networks increased with elevation. The two flight locations weren’t close to any dense residential areas. At ground level, those networks were limited to the immediate area. However, once in the air, that number increased because they were now line of sight. The data logger also captured the three strongest networks detected, along with their RSSI values. Although the network numbers increased, the…

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