Crimsonbot is an open-source modular robotics project under active development at Indiana University’s School of Informatics, Computing, and Engineering (SICE).

This is the 2nd version of the platform, based on the NodeMCU running MicroPython. Documentation for using MicroPython with the NodeMCU can be found here.

This repository contains everything related to the Crimsonbot, which includes both the libraries that Crimsonbot2 users might want to integrate into their projects, as well as admin tools for instructors to use to deploy a fleet of robots in a class.

These different Crimsonbot2-related components are organized by folder:

• libs contains libraries for Crimsonbot2 sensors
• libs_documentation contains information about the libraries from libs
• webrepl contains a mirror of the MicroPython web-based interface, which comes in handy if your computer only has 1 wireless connection, and it’s currently busy with the Crimsonbot2 and can’t connect to the internet
• admin contains tools for teachers to set up individual addresses which makes it easier to manage many ‘bots.
• images contains images and figures used in this documentation

One goal of the Crimsonbot2 project is to provide a limited number of useful libraries for sensors and actuators, both to serve as a model for student-created libraries, and also to allow students to save time by providing a high level interface for devices which can (sometimes) be extremely low-level.

Combining different sensors and actuators is one way to synthesize more interesting robot controls.

Documentation for the libraries is separate, to make uploading libraries simpler.

In the webrepl, use the upload button to find the libs/crimsonbot.py file and upload it to the robot.

Note: download ampy first.

From the command line:

1. navigate to this repository folder cd location/of/this/repository
2. use ampy --port /dev/tty.SLAB_USBtoUART put libs/crimsonbot.py

Note that /dev/tty.SLAB_USBtoUART is how the NodeMCU appears on OSX. On Linux it may be /dev/ttyACM0 or /dev/ttyUSB0. On Windows it may be something like COM3 (unverified). Some guesswork may be required.

Replace step 2 from above with

1. ampy --port /dev/tty.SLAB_USBtoUART mkdir libs
2. ampy --port /dev/tty.SLAB_USBtoUART put libs

More detailed information about various ampy commands can be found using the ampy command-line --help flag, or by reading the source.

1. import it into RAM from within the webrepl python console >>> import crimsonbot as cb
2. now you can use the crimsonbot functions, such as cb.forward(speed) and cb.stop()

We use the NodeMCU revision 2 board. See here for a description of the different revisions. The NodeMCU has physical pins, some of which connect to the on-board ESP8266 chip. It’s important to remember that the physical pin labels on the NodeMCU board are NOT the same as the numbering used by MicroPython.

To use these pins we have to map from the physical pin to the logical pin used in MicroPython.

If the microcontroller is already flashed with MicroPython firmware, you can skip this section, otherwise follow these instructions.

Here’s an overview of the instructions:

1. get the driver if you need it
2. flash MicroPython firmware to board
3. log in to the board over USB/serial, e.g. screen /dev/ttyUSB{id} 115200
4. Enable the webrepl >>> import webrepl_setup and then choose e to enable the webrepl at power-on. Set a password, then reboot.
5. from then on you can connect to the microcontroller over wifi

• esp8266 (separate from NodeMCU)
• web repl
• motor shield
• micropython documentation

IU colors are Cream and Crimson, and the original version of this robot was heavily inspired by the SparkFun RedBot. Our first version also had a translucent red acrylic chassis. Further iterations have kept the name but not necessarily the same color scheme.