IMPORTANT: Please note that this project exists as part of a blog entry, article, or other similar material by AdaCore. It is provided for convenient access to the software described therein. As such, it is not updated regularly and may, over time, become inconsistent with the latest versions of any tools and libraries it utilizes (for example, the Ada Drivers Library).
This is a demonstration program that interacts with the AdaFruit BNO055 breakout board in order to send orientation data to a host computer.The host displays a 3D model of the Apollo Lunar Excursion Module (LEM) via the "Processing" application (see below). The rotation data received from the target computer controls the rotation of the model display in real time.
Rotation data are sent to the host via serial connection. You can use a USB cable specifically designed to appear as a COM port, for example from Mouser (among others):
- Mouser Part No: 895-TTL-232R-5V
- Manufacturer Part No: TTL-232R-5V
- Manufacturer: FTDI
but note that the above is a 5-volt cable in case that is an issue. There are 3-volt versions available as well.
The end of the cable is a female header, described in the datasheet
(DS_TTL-232R_CABLES-217672.pdf). See pages 10 and 11 in particular.
Header pin 4 on the cable is TXD, the transmit data output. Header pin 5 on the cable is RXD, the receive data input.
Connect the cable header pins to the STMicro board GPIO pins as follows:
- header pin 1, the black wire's header slot, to a ground pin on the board
- header pin 4, the orange wire's header slot, to PC7
- header pin 5, the yellow wire's header slot, to PC6
On the host, just plug in the USB-to-serial cable. Once the cable is connected it will appear like a host serial port and is to be selected within the Processing app displaying the model.
The USART is set to: 115_200, N81, no flow control, as expected by the Processing app.
The model is displayed using the Processing app, freely available here:
You must download and install this Processing app on the host computer. The app runs programs -- "sketches" -- in source files with the "pde" extension. Once installed, you can invoke Processing by double-clicking (say) on the specific sketch file that displays the model and listens to the serial port. This program file is named "lander.pde" and is located in a subdirectory of the "processing/" dir included with this Ada program. Within the Processing app, with this sketch file loaded, press the "Run" icon to start the "lander" sketch execution. It does not matter whether you start the program on the ST Micro board before or after the "lander" program. Once "lander" is running in its separate window, select the host port that the ST Micro board is connected to via the cable described above. Now the displayed model will reflect the rotation data coming from the BNO055 via the ST Micro board and the serial connection.
Within the "lander" execution window there is a checkbox that enables display of the incoming serial data. These data are displayed in the Processing app, not in the sketch window. You can use this display to verify data are coming from the ST Micro board. Note that calibration data are included, and that the model display will behave best once the gyro and accelerometer are both calibrated. You will need to manually calibrate the IMU board as usual, i.e., by physically moving it in space.
NOTE: if the sketch running in the Processing app is unresponsive, there may be multiple instances of "java.exe" running (on Windows). If so, shut down Processing app, kill all these java executables, and restart the Processing app (and then press the Run button to run the sketch).
This demo is based on one provided by AdaFruit: https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor/overview
The model we use is available here: https://github.com/nasa/NASA-3D-Resources/tree/master/3D%20Models/Apollo%20Lunar%20Module