SparkFun Triad Spectroscopy not working

Sensors Imaging
1

New try with SparkFun Triad Spectroscopy…

Hooked up SDA,SCL,3.3V, Gnd as instructed. Pull up resistors on SDA and SCL. Ran basic example program. Serial response is

“Sensor does not appear to be connected. Please check wiring. Freezing…”

Tried with Uno and Nano. Sending back to Amazon. Any clues?

2

There should only be one set of pull-ups active on a single bus; it sounds like you need to disable one or the other (there’s a set of i2c pads that you can cut the traces to on the front of the board)

Please note this board works with 3.3v I/O ONLY https://learn.sparkfun.com/tutorials/sp … e-overview …you’ll need to stepdown the I/O from either one of those (Uno, Nano) for it to work as expected

3

So, I bought the Qwiic connector and QWiic 3.3V I2C board, as recommended.

Now, the AS7265X Example program (Basic Readings) prints to the serial monitor “AS7265x Spectral Triad Example” and then hangs indefinitely. No more serial output. No longer does it send the serial output “Sensor does not appear to be connected. Please check wiring. Freezing…” as it did previously. It’s a bit disappointing to have to send this back.

Do you have any suggestion for a fix? I’m planning to use 20 of these in the Fall for an engineering design course, but only if I can get them to work!

4

…After restarting all hardware, disconnecting and reconnecting all circuits, I’m back to:

"AS7265x Spectral Triad Example

“Sensor does not appear to be connected. Please check wiring. Freezing…”

Hardware: Arduino Uno, Qwiic Shield 3.3V I2C, AS7265x Spectral Triad.

Software: IDE: Arduino 1.8.13, Library: Spartan Spectral Triad AS7265X V1.03, Program: Example1_Basic Readings

5

After encountering the same problem using the ESP32-C6-MINI, I implemented a for loop to give the sensor some additional chances to initialize. This has solved the problem for me:

Serial.println("AS7265x Spectral Triad Example");

for (int j=0; j<15;)
    {
      sensor.begin();
      delay (50);

      if (sensor.begin()==true)
      j=50
      ;

      else
      {
        Serial.print("Sensor failed to initialize, retrying... ");
        Serial.print(j+1);  
        Serial.println("/15");

        j++;
      }
    }
6

A 5v microcontroller will work great with this board but you should 100% use a power shifter, or it’s gonna be a headache at best, most likely a brick. Try BSS138 MOSFET power shifters for signal and power (and gnd). They are cheap and should work great. Let me know if i can share wiring diagram, i suggest the 4 channel package (for signal channels plus pwr/gnd with dedicated pull-ups for each channel) on a single board, and don’t use the the sparkfun connectors, they have their own pull-ups i think, which do not map well for the sensor OEM specs.

I am sure it will be argued that mosfets packaged as i describe will be problematic because the introduce dedicated pull-ups which mean multiple pull-ups, but it is not exactly correct to say that multiple pull-ups are a problem, they may even be a solution in this case, if you are using an Uno or other 5v proc. Worst case, you can cut the traces but i’m willing to bet that won’t be necessary and they will work as is.