This python sketch is used in conjunction with phraser.php and litero.html to make a little RasPi-powered rover scoot around and do stuff.

• MJPEG Streamer
  • 160-175deg Wide Angle Camera Module with White/IR LED modules For Raspberry Pi (Banggood)
• RPi.GPIO
  • HG7881 (L9110) Dual Channel Motor Driver (GPIO Pins 17, 18, 22, 27)
  • Navigation LED (2N2222 mod for White/IR LED module) (GPIO Pin 23)
  • Servo control! (Optional, not used by default. Pin 19)
• eSpeak Text-To-Speech
  • LM4871 audio amp conected to GPIO pin #13 (see: PWM1 on GPIO #13 (ALT0) for RasPi Zero W)
• MinIMU-9 (I2C x2)
• ADS1115 ADC (Refer to Adafruit tutorials for setup) (I2C)
• sSMTP

theprogram.py reads from a short text file in RAM (/dev/shm/input.txt) at about 60Hz with parameters that are set at will by a PHP script. The PHP script is being called as the client(s) send in new commands (ex: ./phraser.php?ID=546939&CT=1521479887886&M1=90&M2=90). The client in return gets an XML response that this Python program creates in RAM (/dev/shm/output.txt) along with an ongoing live view from the bot using MJPEG-Streamer.

LiTeRo by default will speak its local ip address on bootup. It will also guide you through the magnetic compass calibration when mag_calibration.txt is removed before bootup.

• For the Raspberry Pi Zero, you should enable audio out on one of the GPIO pins in order to use TTS (see: PWM1 on GPIO #13 (ALT0) for RasPi Zero W).
• Make sure Apache, PHP, Python, SSMPT, mjpeg-streamer, eSpeak, and the Adafruit_ADS1x15 Python library are installed for FULL functionality. Other libaries may be present in the top of the python code.
• In the raspi-config; enable i2c, ssh, remote GPIO, and the camera. (uart is also useful if you want to configure the Pi without removing the SD card.)
• Make "thecode.py" run on startup. Put the following in /etc/rc.local

#my telepresence bot code
sleep 30s
sudo python /var/www/html/thecode.py &