Grove spectrometer

Products & Technology New Product Ideas
#1

I’m looking for a spectrometer.

  • ams AS7262: Consumer Grade Smart 6-Channel VIS Sensor albeit Not Recommended for New Designs
  • ams AS7341: 11-Channel Spectral Color Sensor, recommended

Both sensors connect through I²C and thus fit perfectly with the Grove system.

The ams AS7341 is especially great with a total of 11 channels:

  • 8 channels for colours on the visible range,
  • plus 3 extra channels for Clear, Flicker and near infra-red.

External components should be minimum, with an 1.8V LDO and logic level converter.

#2

Hi @reivilo
Here is the only one spectrometer that we have, it is based C12880ma spectrometer head that supports the long-wavelength region(up to 850 nm).

#3

The breakout boards from other suppliers are about USD20, hence the idea for a Grove new product at a more affordable price point.

#4

Thank you for these detailed information, would be very helpful when designing a new product.

#5

I have build a spectrometer using the Sparkfun “AS7265x Spectral Triad” connected to a WIO terminal.
The sensor has actually 3 sensors, each with 6 channels (20nm width). It covers the visibable range as well as near IR. Interface is I2C.
I use it to verify NVIS (night vision) compatibility.

#6

On my side, I’ve ordered the Adafruit AS7341 10-Channel Light / Color Sensor Breakout - STEMMA QT / Qwiic but haven’t had time yet to test it.

#7

At least cheaper than mine, but for me it lacks some spectral data points in the area that is important for my application.

#8

Actually, I hadn’t much choice, as Sparkfun products are not as widely available as Adafruit ones in Europe.

#9

Digikey has them and ships to Europe. I got it from Digikey to Taiwan.

#10

I gave a try to the Adafruit AS7341 10-Channel Light / Color Sensor Breakout - STEMMA QT / Qwiic with the Wio Terminal.

Here is a screen-shot:

AS7431

We see the ten channels (colours and wavelengths) and the flicker detection (top right).

Processing the data would be easier with a neural network, as I did previously with my Colour Recognition with Neural Network project based on the Intel Curie board.

#11

I just purchased the Triad but after reading " The Serial Basic is set to 3.3V by default but if you’re using a different board, be sure it provides 3.3V on VCC and uses 3.3V logic signals" I was nervous about connecting it to my WIO TERMINAL. I was not sure what voltage the SDA and SCL lines were. If yours worked then the WIO Terminal must accommodate?
I also purchased a TFMINI Lidar from SparkFun but it does not work well with 3v3. It also works with 5V but the SDA and SCL MUST remain 3v3. Would that work on WIO TERMINAL I2C?

#12

I see no problem. I expect it to work.

#13

Hi! I tried to connect the Triad with the WIO Terminal using a QWIIC to Grove adapter cable, but when i use Triad Example 1 in the library that comes with it, it says that the sensor does not appear to be connected. Basically sensor.begin() == false in startup. How did you wire it, and any idea why the qwiic->grove wouldn’t work? they’re both i2c so the wiring should be the same

#14

In case voltage was a factor, I also tried using breadboard jumper wires to connect from the WIO GPIO on the back, 1,3,5,9 (which should be 3.3, 1-SDA, 1-SCL, Gnd) to the 3.3, SDA, SCL, and Gnd spots on the bottom of the TRIAD and got the same thing.

#15

The pinout of the Triad is incorrect. Pins SDA and SCL are swapped. This mentioned somewhere in the docs for the sensors.

#16

Wow. Thanks!!! I read a lot but didnt see that. THANK YOU!!

Edit: Hmmm… No joy. Switched them but still the same. Does it matter if I am using ItC1_SDA/SCL or ItC0_SDA/SCL ??

#17

I will check when I have the sensor back. Currently it is integrated into some other jig.
But I remember that I simply used the supplied library. Nothing special.

Reinhardt

#18

Tested it again and it works on the WIOTerm’s I2C (left connector, seen from the front side).
The code can be found here:
https://www.dropbox.com/sh/imd9yafd9bwt7nh/AABG0gjdjELJQWplyfVahciwa?dl=0

20220426_215439
20220426_2154391920×1396 227 KB

The WIO buttons (left/right) increase/decrease the scale factor .
Middle button turns the illumination LED on/off.

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