Sample MicroPython code for M5Stack with AMG8833

m5stack-amg8833-main.py

# MicroPython sample program for M5Stack with AMG8833

"""
COPYRIGHT

This code is licensed under the MIT license. 
<https://opensource.org/licenses/MIT>

Copyright (c) 2018 Switch Science, inc.

Permission is hereby granted, free of charge, 
to any person obtaining a copy of this software and 
associated documentation files (the "Software"), to 
deal in the Software without restriction, including 
without limitation the rights to use, copy, modify, 
merge, publish, distribute, sublicense, and/or sell 
copies of the Software, and to permit persons to whom 
the Software is furnished to do so, 
subject to the following conditions:

The above copyright notice and this permission notice 
shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 
ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"""

# MicroPython Firmware
# https://github.com/m5stack/M5Cloud/blob/master/firmwares/OFF-LINE/m5stack-20180206-v0.3.3.bin
#
# M5Stack Basic
# http://www.m5stack.com/
# 
# Panasonic Grid-EYE AMG8833
# https://industrial.panasonic.com/jp/products/sensors/built-in-sensors/grid-eye
#
# Blog  
# http://mag.switch-science.com/2018/02/28/getting-started-with-m5stack/
#
# Usage
# Save this code as main.py then restart.
# Button A : Start drawing grid matrix of thermal data.
# Button B : Caribration
# Button C : Stop drawing
#

# Note. 
#
# The latest MicroPython Firmware changed the name of buttons.
# So you might want to change the code on your case.
# eg. BtnA -> buttonA
#
# This code written and tested on M5Stack Basic and M5Stack Watch.
# With M5Stack Gray or M5Stack Faces, you might want to set I2C address of AMG8833 other than 0x68, since 0x68 is used for MPU9250 DoF sensor.
#

from m5stack import lcd, BtnA, BtnB, BtnC
from machine import I2C
import ustruct

colors = (0x0000FF, 0x0008FF, 0x0010FF, 0x0018FF, 0x0020FF, 0x0028FF, 0x0030FF, 0x0038FF, 0x0040FF, 0x0048FF, 0x0050FF, 0x0058FF, 0x0060FF, 0x0068FF, 0x0070FF, 0x0078FF, 0x0080FF, 0x0088FF, 0x0090FF, 0x0098FF, 0x00A0FF, 0x00A8FF, 0x00B0FF, 0x00B8FF, 0x00C0FF, 0x00C8FF, 0x00D0FF, 0x00D8FF, 0x00E0FF, 0x00E8FF, 0x00F0FF, 0x00F8FF, 0x00FFFF, 0x00FFF7, 0x00FFEF, 0x00FFE7, 0x00FFDF, 0x00FFD7, 0x00FFCF, 0x00FFC7, 0x00FFBF, 0x00FFB7, 0x00FFAF, 0x00FFA7, 0x00FF9F, 0x00FF97, 0x00FF8F, 0x00FF87, 0x00FF7F, 0x00FF77, 0x00FF6F, 0x00FF67, 0x00FF5F, 0x00FF57, 0x00FF4F, 0x00FF47, 0x00FF3F, 0x00FF37, 0x00FF2F, 0x00FF27, 0x00FF1F, 0x00FF17, 0x00FF0F, 0x00FF07, 0x00FF00, 0x08FF00, 0x10FF00, 0x18FF00, 0x20FF00, 0x28FF00, 0x30FF00, 0x38FF00, 0x40FF00, 0x48FF00, 0x50FF00, 0x58FF00, 0x60FF00, 0x68FF00, 0x70FF00, 0x78FF00, 0x80FF00, 0x88FF00, 0x90FF00, 0x98FF00, 0xA0FF00, 0xA8FF00, 0xB0FF00, 0xB8FF00, 0xC0FF00, 0xC8FF00, 0xD0FF00, 0xD8FF00, 0xE0FF00, 0xE8FF00, 0xF0FF00, 0xF8FF00, 0xFFFF00, 0xFFF700, 0xFFEF00, 0xFFE700, 0xFFDF00, 0xFFD700, 0xFFCF00, 0xFFC700, 0xFFBF00, 0xFFB700, 0xFFAF00, 0xFFA700, 0xFF9F00, 0xFF9700, 0xFF8F00, 0xFF8700, 0xFF7F00, 0xFF7700, 0xFF6F00, 0xFF6700, 0xFF5F00, 0xFF5700, 0xFF4F00, 0xFF4700, 0xFF3F00, 0xFF3700, 0xFF2F00, 0xFF2700, 0xFF1F00, 0xFF1700, 0xFF0F00, 0xFF0700)

i2c_address = 0x68
register = 0x80

ison = False

offset = 0
rate = 1

i2c = I2C()

def getval(val):
  absval = (val & 0x7FF)
  if val & 0x800:
    return - float(0x800 - absval) * 0.25
  else:
    return float(absval) * 0.25

def minmax():
  global offset
  global rate
  reg = register
  min_temp = 1000
  max_temp = -1000
  for i in range(0, 64):
    val = ustruct.unpack('<h', i2c.readfrom_mem(i2c_address, reg, 2))[0]
    tmp = getval(val)
    if tmp < min_temp:
      min_temp = tmp
    if max_temp < tmp:
      max_temp = tmp
    reg += 2

  diff = max_temp - min_temp
  # add some margin
  diff *= 1.4
  rate = len(colors) / diff
  offset = min_temp * 0.8

  lcd.clear()
  lcd.print('min:    ' + '{:.2f}'.format(min_temp), 0, 0)
  lcd.print('max:    ' + '{:.2f}'.format(max_temp), 0, 10)
  lcd.print('rate:   ' + '{:.2f}'.format(rate), 0, 20)
  lcd.print('offset: ' + '{:.2f}'.format(offset), 0, 30)

def graph():
  global offset
  global rate
  reg = register
  for ic in range(0, 8):
    for ir in range(0, 8):
      val = ustruct.unpack('<h', i2c.readfrom_mem(i2c_address, reg, 2))[0]
      tmp = (getval(val) - offset) * rate
      if tmp < 0:
        tmp = 0
      if 127 < tmp:
        tmp = 127
      lcd.rect(ic * 30 + 40, ir * 30, 30, 30, 0, colors[int(tmp)])
      reg += 2

def loop():
  global ison
  while True:
    if BtnA.press():
      ison = True
    if BtnB.press():
      minmax()
    if BtnC.press():
      ison = False
    if ison:
      graph()

loop()