micropython-ttgo-wristband

Code and data about TTGO/LilyGo T-Wristband and running MicroPython on it

MicroPython code for the T-Wristband platform. My wristband has an external battery attached - and a vibromotor, too. It vibrates every minute. It can also do more.

Working:

• I2C interface
• Touch button
• Deepsleep wake using touch button
• Display backlight (PWMed)
• Display
• VBAT ADC
• VBUS ADC
• Charging detection
• MPU-9250
• RTC - no lib brought in, but it's query-able over I2C alright (use this?)

Not yet fully working (code not written/not yet tested/imperfect):

• Properly bringing out the display from low-power mode after deepsleep without a hardware reset of the display

• Bringing up the display after a Ctrl+D soft reset (is brought up from power-on reset and from deepsleep reset)

• Some GPIOs might not be brought into/from deepsleep correctly. This might be causing the two previous problems.

• main.py

  • My current main.py file

• hw.py

  • File with hardware definitions - pins, interfaces, some helper functions

• st7735.py

  • st7735 driver - not mine, taken from some other project, is under a different license

• pwm_pin.py

  • An object for a PWM-driven pin that still allows to treat the PWM object as a pin ( with .on(), .off() and .value(value) )

• wifi.py

  • File for your WiFi settings

• ttp223_deepsleep_example.py

  • A standalone example of how to do deepsleep with the TTP223

• orig_image.bin

  • The original ESP32 image that the wristband came flashed with from the factory. Source is not available, so, the image by itself is of interest.

• original_firmware_serial_log.txt

  • Log produced on the serial port when the original image executes and the touch button is pressed. Recorded using screen -L /dev/ttyUSB0 115200

• original_firmware_serial_log_commented.txt

  • Same log, but with comments marking moments when the button is pressed and when different things are shown on the screen

• read_orig_image_cli.sh

  • Script that contains the commandline to read the original image from the ESP32

• write_orig_image_cli.sh

  • Script that contains the commandline to write the original image back to the ESP32

• interesting_things_orig_image.md

  • Interesting observations about the original image

• esp32-idf4-20191220-v1.12.bin

  • The MicroPython image I'm using with this board

• flash_micropython.sh

  • A script to flash the MicroPython image included

MPU9250 bringup is two-step. AK8963 won't appear on the I2C bus (0x0C address) until you enable I2C passthrough mode on the MPU6500, and, this board has a different I2C address for the MPU6500: 0x69.

>>> from mpu9250 import MPU9250
>>> from mpu6500 import MPU6500
>>> m = MPU6500(i2c, address=0x69)
>>> m = MPU9250(i2c, mpu6500=m)
>>> i2c.scan()
[12, 81, 105]

MPU9250 code available from here