Program for thermal imaging camera with MLX90640 far-infrared (IR) thermal sensor srray for XIAO ESP32S3 and ESP32-2432S028R
It comes with a graphical user interface to properly configure the MLX90640 for different scenarios.
- Display frame rate: 1 FPS (min) / 16 FPS (max)
- Resolution: 32 x 24 (min) / 256 x 192 (max)
- Heat map mode: Rainbow / Inferno
- Measurement range: Auto scaling / Manual adjustment.
- Measurement features: Automatic min/max / a specified point.
- Screen capture: Save 320 x 240 bitmap (24-bit) to SD card.
- Video recording: Record 32 x 24 raw data continuously onto SD card.
- File explorer: Display thumbnails / Play videos on SD card.
- Offline video viewer: Offline video playback on PC
- Touch screen: Calibration on the first launch / in the configuration menu.
For GPIO pin assignments, see pin_assign.h.
I2C pull-up registers
- Arduino IDE : 2.3.4
- Board package : esp32 by Espressif Systems : 3.1.1
Board type: - Adafruit_MLX90640 1.1.1
- GFX library
- Touchscreen library (only for TFT_eSPI on CYD)
- XPT2046_Touchscreen : Version 1.4 or
- XPT2046_Bitbang_Slim : v2.0.1
MLX90640.ino
├─ pin_assign.h
├─ heatmap.h
│
├─ mlx.hpp
├─ gfx.hpp
│ │ <LovyanGFX.h>
│ ├─ boards
│ │ ├─ LGFX_CYD_2432S028R.hpp
│ │ └─ LGFX_XIAO_ESP32S3_ST7789.hpp
│ │ <TFT_eSPI.h>
│ ├─ User_Setup.h
│ └─ boards
│ ├─ Setup_CYD_2432S028R.h
│ ├─ Setup_XIAO_ESP32S3_ST7789.h
│ └─ XPT2046_ScreenPoint.h
├─ task.hpp
├─ touch.hpp
├─ sdcard.hpp
├─ filter.hpp
├─ interpolation.hpp
└─ widget.hpp
├─ draw.hpp
│ └─ marker.h
└─ widgets.hpp
└─ widgets.h
-
Depending on the board type, define pinouts of the I2C for MLX90640 and SPI for LCD / touch screen / SD card in
pin_assign.h. -
Configure each step in
MLX90640.ino. Generally, there is no need to change the default values.
- Step1: Debugging mode (default:
false) - Step2: Operational specifications
ENA_INTERPOLATION(default:true)ENA_MULTITASKING(default:true)ENA_OUTWARD_CAMERA(true: Outward,false: Selfie)
- Step3: GFX library
USE_LOVYAN_GFX(default:true, highly recommended)USE_AUTODETECT(default:true, or manual settings)
USE_TFT_ESPIUser_Setup.h(definition required)
- Step4: Flash memory
USE_PREFERENCES(default:false,trueis recommended.)
- Step5: Resolution
For low performance MCUs. No modifications required.
It achieves parallel processing by utilizing multi-cores with FreeRTOS and double-buffering for thermal images.
Timing diagram
The “Calibration Screen” will appear when you run the sketch for the first time after compile & uploading, or when you select to run calibration from the menu.
Calibration Screen
If USE_PREFERENCES is set to true, you can save the calibration results to flash, but when it's set to false,
you need to open the serial monitor with 115200 bps before running the calibration and embed the displayed data into
touch.hpp after calibration is completed.
- When TFT_eSPI is selected,
- rendering will be slower than LovyanGFX on ESP32-2432S028R.
- screenshots can not be saved correctly on XIAO_ESP32S3.
-
MLX90640Viewer
The MLX90640Viewer is a tool that applies heatmaps and visualizes the output of the Melexis MLX90640 32x24 IR array, which is stored as continuous raw data in a file.