Imported from GitHub: sherrardTr4129/RealSense-BNO055-Pose-Estimation · commit ca48f11 · license MIT

Description

This repository contains required software to construct a Pose of a vision target by fusing its x,y,z coordinates from the Intel RealSense depth camera, with its quaternion orientation from the BNO055 sensor.

README

Orientation Capture Sub-System Designs (Electrical and Mechanical) and Firmware

This directory contains the hardware designs (mechanical and electrical) and firmware needed to construct the wireless orientation capture system used for more robust motion capture.

Overall System Specifications

The table below outlines some basic specifications for the overall orientation capture sub-system:

Specification	Value
Transmitter Range	At least 5m (probably much more even at the NRF24_PA_LOW value)
Transmitter Sub-System Current Consumption (steady state)	~50mA
Battery Life (Assuming 1Ah cell)	~20 hours
Transmitter Input Voltage (4 AA battery cell recommended)	5V - 6V
Overall System Data Frame Rate	~30 FPS

Electrical Hardware Designs

For this project, a PCB was designed containing all required hardware to read data packets from the BNO055 sensor and transmit them wirelessly to a basestation, where they can be read in by the aforementioned ROS driver. The kiCAD project containng the schematic and board layout files can be found in the electricalHardware/wirelessOrientationSensorSystem directory in this repository. Please see below for a wiring diagram for both the base-station and wireless transmitter board and well as real pictures of each device.

Sensor Data Transmitter

Please note that this diagram depicts the wireless data tranmission module in its operational state. More connections are required to flash the firmware to the device. These connections and the firmware flashing process will be outlined later in this readme.

Sensor Data Reciever

Firmware

The firmware flashing process for each of the board assemblies can be seen in each respective sub-section.

Sensor Data Transmitter Firmware Flashing Procedure

As this board uses a unflashed ATMEGA328P processor, we must first flash the arduino bootloader to the device. The first step in this process is to wire an external arduino uno to the wireless data transmitter board in the configuration seen below.

From here, upload the arduino as ISP sketch to the arduino uno found under File->Examples->ArduinoISP. Once this successfully uploads to the arduino uno, the bootloader can be flashed. The first step in the flashing process is to change the programmer under Tools->Programmer from "AVRISP mkll" to "Arduino As ISP". From here, click Tools->Burn Bootloader. If the process works as expected, a "bootloader flashed successfully" message will appear in the status window of the IDE

To flash the application level firmware onto the board, first disconnect the arduino uno from the wireless sensor transmitter board. From here, wire up the FTDI USB to TTL Serial converter to the wireless sensor transmitter as shown in the figure below.

From here, open the BNO005_Capture_and_Transmit.ino file in the Arduino IDE. Change the programmer back to "AVRISP mkll" from "Arduino As ISP". Make sure the correct serial port and board type (arduino uno) are selected under the tools menu. From here, click the upload button, and the source should compile and be uploaded to the MCU.

Sensor Data Reciever Firmware Flashing Procedure

The process for flashing the firmware for the reciever sub-system is the same as flashing any standard Arduino Uno. Just make sure you have all the NRF24 dependencies installed and compile and upload the firmware.

Mechanical Hardware Designs

The mechanical hardware designs for both the vision target and the base station can be seen in the rendered images below. Note that both the these STL files are available in this repository.