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Dennis Boldt edited this page May 23, 2020 · 9 revisions

Development

Create a new configuration

  • config.h
    • Add config variable to Config-Struct
  • config.ino
    • Add new variable to loadConfiguration
    • Add new variable to saveConfiguration
    • Add new variable to printConfiguration
  • configServer.h
    • Add new variable to HTML template
  • configServer.ino
    • Add new variable to the corresponding handler function, to save it
  • Use the new config variable in the code

Text-grid

To avoid pixel-based adressing, a simple grid was introduced:

---------------------------------
| (0,0) | (1,0) | (2,0) | (3,0) |
---------------------------------
| (0,1) | (1,1) | (2,1) | (3,1) |
---------------------------------
| (0,2) | (1,2) | (2,2) | (3,2) |
---------------------------------
| (0,3) | (1,3) | (2,3) | (3,3) |
---------------------------------
| (0,4) | (1,4) | (2,4) | (3,4) |
---------------------------------
| (0,5) | (1,5) | (2,5) | (3,5) |
---------------------------------
  • A text is only updated, when it changes, thus calling the function with the same text again and again does not update the display!
  • A text is updated as follows: When the text differs, the privious text is written in BLACK, thus the text is erased. Afterwards, the new text is written in white. Finally the diplay is updated.
  • There are two functions on the Display class:
    • showTextOnGrid(int16_t x, int16_t y, String text)
      • Puts a text on (x,y) in font size 10
    • showTextOnGrid(int16_t x, int16_t y, String text, const uint8_t* font)
      • A Specific font can be used, e.g. 20 pixel: display->showTextOnGrid(0, 0, "Hello World", Dialog_plain_20)

Install esptool

git clone [email protected]:espressif/esptool.git
cd esptool/

Detect maximum flash size with esptool (Ubuntu)

./esptool.py --port /dev/ttyUSB0 flash_id | grep "flash size"

Detected flash size: 4MB

The ESP32 has 4MB flash memory!

Flash binary with esptool (Ubuntu)

  • Install esptool:
  • Download the newest release.
  • Connect a microUSB cable directly to the ESP32 (the USB-C port at the case is only for charging the battery)
  • Detect the correct port: 
    ls /dev/ttyUSB*
  • Run the flash command: 
    ./esptool.py \
  --chip esp32 \
  --port /dev/ttyUSB0 \
  --baud 921600 \
  --before default_reset \
  --after hard_reset write_flash \
  0x10000 ~/Download/OpenBikeSensorFirmware.ino.esp32.bin

Hint:

At a 0x10000 (64KB) offset in the flash is the app labelled “factory”. The bootloader will run this app by default.

See: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/partition-tables.html

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