A repository to hold recourses related to the development / use of the Spartronics Autonomous Tetrix Platform.

AccesspointWS is the communication/Remote-Control component for our mobile robot. It currently targets https://robotdyn.com/uno-wifi-r3-atmega328p-esp8266-32mb-flash-usb-ttl-ch340g-micro-usb.html, but could be retargeted to other "wifi-equipped" IOT models.

AccesspointWS sets up a wifi access point named RoboNet and offers a websocket service on ws://192.168.4.1:81.

WebSocketServer accepts connections then routes incoming url-like messages to control settings on the esp8266 and/or the arduino code. To dispatch messages to arduino (where, eg, motors are controlled), the esp8266 program employs Serial.println. Note that this only works when the DIP switches on the robodyn are configured 11000000 (or 11110000, or 11001100).

In this implementation, websocket messages take the form of a url with url-encoded parameters. The Arduino-side handling is implemented in the robodyn project and responds to urls like this:

`/ard?led=on&M1=.25&M2=.25&`

or this:

`/esp?led=on&`

The interpretation of the messages is up to the target program.

To obtain status from the robot, we can either return status as part of the url protocol or implement a UDP broadcast on the esp8266. Since most status is expected to reside on the Arduino side, the esp8266 must be provided status from the Arduino code.

• python websockets (see blinky.py):
  • python -m pip install asyncio websockets
  • python blinky.py (toggles two LEDs 10 times per sec).
• web browser with javascript
  • currently the esp code (accesspointWS) doesn't offer a http server. The companion project, accesspoint, demonstrates that http is too slow for control and may therefore not be worth the extra complexity.
  • one could easily develop a desktop server, analogous (or equivalent to?) the Spartronics Dashboard server that runs on the driver station and connects to the websocket.

Remember: the robodyn is a board with two different programmable chips and two different machine architectures. We must select/configure toolset for each architecture and make sure that the dev settings are correct for the target chip. This directory contains programs for the esp8266 and a companion directory, robodyn, contains a program for the arduino-uno.

A non-standard platform library is required for websockets. We are currently using this websocket implementation: https://github.com/Links2004/arduinoWebSockets, with a tutorial here: https://tttapa.github.io/ESP8266/Chap14 - WebSocket.html. The websocket library should be compiled with debugging strings disabled via a commandline define (or by editing the header file).

-DNODEBUG_WEBSOCKETS

To upload code to esp8266, set DIP switch to:

• 00001110 to upload this sketch (red 8266 LED illuminates)

Run upload.py (jsmk test), press reset button before initiation.

To run code on esp8266, set DIP switches to:

• 11110000 to run with comms enabled and listen on ard-side println. This is the preferred operating mode.
• 11001100 to run with comms enabled and listen on esp-side println

Now you should be able to connect to the wifi accesspoint RoboCtl and view the debugging console with arduino IDE Serial Monitor.

Controls arduino-uno side pins for input and output. Listens on serial connection to wifi-enabled esp8266 for command/control. See esp8266/accesspointWS for more on the wifi side.

• receive a url-encoded reqwuest over serial to establish/modify our runtime behavior.
• send updates of current state (sensors, motor-levels, etc) periodically
• turn motors off if we haven't received a heartbeat within the motor-safety interval.

Set DIP switch to:

• 00110000 to upload sketch
• 11001100 to run with comms enabled and listen on esp-side println
• 11110000 to run with comms enabled and listen on ard-side println

Run avrdude (via jsmk test), press reset button right after initiation.

https://robotdyn.com/uno-wifi-r3-atmega328p-esp8266-32mb-flash-usb-ttl-ch340g-micro-usb.html