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A list of all the posts and pages found on the site. For you robots out there, there is an XML version available for digesting as well.
Pages
rjmendez.github.io
About me
Posts
Wildflower Seeds
Published:
We moved to PA in 2023 and our property has a rather large and very plain looking power line easement. Previous owners had been mowing it every few months and as a result the plant biodiversity is pretty low consisting of mostly Timothy Grass with a few blackberry bushes spreading out of the woods.
Inspiration
I like to look at wildflowers damn it. Going outside and collecting seed heads from wild plants on the roadside while effective still means I need to spread them on the easement somehow. I figured why not make something airborne? Enter the seed drone!
Hardware
The drone is a pretty common custom made 5 inch prop FPV drone, its running a betaflight firmware (4.5.1). The seed deployment mechanism consists of a 9g servo and a rubber band. The servo proved to be the most frustrating part of this build. The drone flight controller is a SpeedyBee F7 V3 with the servo signal line going to motor pad 5 (M5) with the ground and +5v to their pads.
The motor controller outputs more than enough power for a 9g servo, that servo rotates the control horn releasing the rubber band and flinging seeds. Depending on the type of seeds they can be wind dispersed or scattered by gravity alone, below is an example of wind dispersed Joe Pye weed and wild lettuces.
Other seeds like to be in a soil seed bank and they can be packed into “seed balls” made of clay and compost. 
Still others are perfect for dropping loose but packed for flight using “natural materials” found around the forest. 
Demonstration of the loose seed deployer in action.
Software
By default Motor 5 is mapped to output B07, since I’m not using motor 5 for a flight motor we can redefine Servo 1 to use that output.
# resources
resource MOTOR 5 NONE
resource SERVO 1 B07
Next we need to make sure that CHANNEL_FORWARDING is enabled in betaflight, I’m using channel AUX 1 for the seed deployer Servo 1 with that mapped to a pushbutton on the radio transmitter. By default the channel_forwarding_start param maps AUX 1 to Servo 1
References:
https://betaflight.com/docs/wiki/guides/current/servos-and-servo_tilt-for-3-1
MycoMIDI - Mushrooms as musical instruments
Published:
Every so often when I’m dealing with a lot of stress I end up making strange projects. I had a dream where I had synesthesia, movements of muscles and joints had distinct sounds and actions like walking or running played different melodies. As a result I ended up learning about human nerve action potentials and their electrical spikes.
Inspiration
My goal was to turn bioelectrical signals into “music” of a sort, attaching electrodes to myself would be quite uncomfortable long term but I was already growing Oyster and Lions Mane mushrooms for food.
Plantwave - https://plantwave.com/
BioAmp-EXG-Pill - https://github.com/upsidedownlabs/BioAmp-EXG-Pill
Hardware
On a whim I pulled a retired mycelium block from the compost and hooked some electrodes to it. The signals were barely noticable on an oscilloscope so an amplifier was needed, enter the BioAmp-EXG-Pill!

With the amplification sorted out the signal needed to be converted into a MIDI signal, a Raspberry pi and ADS1256 ADC was pulled from the parts bin with each channel assigned to an amp.


All wired up

Fruiting mushroom block

When the blocks are done fruiting they get retired to the great outdoors and then composted

Software
Embedded hardware firmware extraction and analysys: Part 3 ARM
Published:
ARM Cloud Conected Camera
Embedded hardware firmware extraction and analysys: Part 2 MIPS
Published:
MIPS Network Appliance
Embedded hardware firmware extraction and analysys: Part 1
Published:
What are ARM and MIPS?
ViaSat rm4100 Console Access
Published:
This is part of a series on reversing the ViaSat rm4100 satellite modem.
ViaSat rm4100 Memory Dump
Published:
This is part of a series on reversing the ViaSat rm4100 satellite modem.
ViaSat rm4100 uart identification
Published:
This is part of a series on reversing the ViaSat rm4100 satellite modem.
portfolio
Portfolio item number 1
Short description of portfolio item number 1
Portfolio item number 2
Short description of portfolio item number 2 
publications
Paper Title Number 1
Published in Journal 1, 2009
This paper is about the number 1. The number 2 is left for future work.
Recommended citation: Your Name, You. (2009). "Paper Title Number 1." Journal 1. 1(1).
Download Paper | Download Slides | Download Bibtex
Paper Title Number 2
Published in Journal 1, 2010
This paper is about the number 2. The number 3 is left for future work.
Recommended citation: Your Name, You. (2010). "Paper Title Number 2." Journal 1. 1(2).
Download Paper | Download Slides
Paper Title Number 3
Published in Journal 1, 2015
This paper is about the number 3. The number 4 is left for future work.
Recommended citation: Your Name, You. (2015). "Paper Title Number 3." Journal 1. 1(3).
Download Paper | Download Slides
Paper Title Number 4
Published in GitHub Journal of Bugs, 2024
This paper is about fixing template issue #693.
Recommended citation: Your Name, You. (2024). "Paper Title Number 3." GitHub Journal of Bugs. 1(3).
Download Paper
Paper Title Number 5, with math \(E=mc^2\)
Published in GitHub Journal of Bugs, 2024
This paper is about a famous math equation, \(E=mc^2\)
Recommended citation: Your Name, You. (2024). "Paper Title Number 3." GitHub Journal of Bugs. 1(3).
Download Paper
talks
teaching
Teaching experience 1
Undergraduate course, University 1, Department, 2014
This is a description of a teaching experience. You can use markdown like any other post.
Teaching experience 2
Workshop, University 1, Department, 2015
This is a description of a teaching experience. You can use markdown like any other post.


