#nodebot

[justinarrakis-blog]

Cadence

9/15/2018 - Day 4

Listening to: FM-84 - Mainframe

I found out today having a PWM wire today on a servo only makes the torque of the servo weaker, it does nothing for the speed. So I set out to work on ways to potentially slow the servo down during transition. I also needed to find a way to stop the servo in the middle of its transition in order to give it a new position command. This is important as when the hexapod finds a new path or takes in new information when it is navigating, it will need to change its motion on the fly before walk cycles of certain limbs are completed. This is a common occurrence in normal animals as they walk, thus it needs to be an available option with the hexapod. 

After most of the day looking into a setInterval() loop checking on input angles set in variables and doing a compare against them with the current angle for each servo, I realized I was over complicating it. The current johnny five API servo methods have the ability to set speed, I can also call a stop on a servo when a new command is passed into the socket. However I might still need to look into setInterval, as new commands will need to be passed into a loop, however the socket connection check loop will no longer be listening for these types of commands, the script itself might be passing these commands. Im still working out this configuration, but I have successfully interfaced with a servo and controlled its speed and interrupted its transition with a new position command. I will have to purchase a few servos to try and create patterns and control multiple at once. I also need to look into control boards for controlling multiple servos. 

[justinarrakis-blog]

Communications

9/12/2018 - Day 2

Listening to: H.U.V.A. Network - Diagrams

I am now able to successfully control the Arduino board connected to my RPi through USB serial with a socket.io connection to the RPi from my remote terminal. Currently I am serving a small webpage with the slider with 10 possible positions. When changing the position of the slider, the value is emitted through the socket connection into the RPi. The socket connection in the API I have set up on the RPi then routes the value date into the socket.on() listener that picks up the new value and sends that value to the nodebot connection to the Arduino. I can now control the RPi and anything connected to it with javascript from anywhere with a network connection. In the future, I plan on extending this connection beyond wifi and making it cellular, so essentially my RPi will have no effective range as long as its within the range of a cell tower.

Now that I have firmly established communications with the RPi in a configuration that suits my needs for the foreseeable future, I can move on to other tasks. I might still try to do some fun things with this... including testing the hook up of two different Arduino boards (adding on my Uno) to the RPi and controlling them individually. But beyond that it is now time to study movement in robotics and how I can make 6 legs mimic insectoid movement. The first step in this is to see if I can find any materials surrounding the board configuration and programming around leg movement of existing Hexapod projects. The node bot interface was new territory with not a lot of documentation and this new task should be better supported.

[justinarrakis-blog]

Node-Bot

9/11/2018 - Day 1

Listening to: FC Kahuna - Hayling

After some deliberation, I decided to go down the path of running johnny-five.io as the main controller of the RPi and any connected arduinos/microcontrollers. I have successfully installed node, express, and the arduino IDE onto the RPi. I was able to create a sketch on my Arduino using the standard Firmata sketch using standard guides when considering I working through the RPi VNC I have established instead of on the desktop of the computer I am currently on. After the sketch was properly installed, I was able to run the standard LED blink test outlined here: http://johnny-five.io/examples/board-with-port/ 

I have also been able to initiate an express server with a very minimal webserver. However when attempting to host a socket IO connection, I have experienced various errors that I have to work through. While I might not rest on socket IO to initiate commands to my RPi from a remote connection and might stick with regular get and post commands via hosted API, I do want to test on its viability. 

I will continue testing tomorrow and hopefully will make a breakthrough. My current repo with my progress is located here: https://github.com/JSArrakis/Leviathan however beware, my code isn’t carefully documented as of yet and wont be until I have working examples that have a high fidelity of success.