Thermopile Shield

The Thermopile Shield gives the OpenMV Cam a 16x4 thermal-sensor array over I2C for low-resolution thermal imaging and per-pixel temperature measurement.

For full datasheet, photos, and ordering see the Thermopile Shield product page.

Highlights

• 16x4 thermal sensor array, 60 deg x 16 deg field of view

• Object temperatures from -50 C to 300 C

Pinout

Pin reference

Pin	Function
P4	I²C SCL — clock to the thermopile array
P5	I²C SDA — data to the thermopile array
3.3V rail	Powers the thermopile
GND rail	Common ground

Usage

Capture a heat-map from the on-board thermopile array via the fir module:

import fir
import image
import time

fir.init()

clock = time.clock()
while True:
    clock.tick()
    try:
        img = fir.snapshot(x_scale=10, y_scale=10,
                           color_palette=image.PALETTE_IRONBOW,
                           hint=image.BICUBIC,
                           copy_to_fb=True)
    except OSError:
        continue
    print(clock.fps())

Read the raw per-pixel temperatures as a 16×4 ndarray of celsius floats. fir.read_ir() also returns the ambient temperature and the min/max seen in the frame:

import fir
import time
from ulab import numpy as np

fir.init()
w = fir.width()
h = fir.height()

while True:
    try:
        ta, ir, to_min, to_max = fir.read_ir()
    except OSError:
        continue
    grid = np.array(ir).reshape((h, w))
    print("Ambient: %.1f C, range: %.1f to %.1f C, mean: %.1f C"
          % (ta, to_min, to_max, np.mean(grid)))
    time.sleep(1)