Quad Relay not detected on QWIIC i2c bus

Qwiic System
1

Test setup:

Hardware:

Sparkfun Thing Plus (WRL-15663) connected via QWICC connector to: 1) Quad relay (COM-16566) and 2) Digital Temperature Sensor TMP102 (SEN-13314).

The two breakout boards are daisy-chained and I have tried them in both orders (ESP32 → Temp → Relays and ESP → Relays → Temp). The relay board is connected to a 12V DC power supply and the red power indicator LED is on.

Software:

Micropython 1.13

Main.py:

from machine import Pin, I2C
import sys

sda_pin = Pin(23)
scl_pin = Pin(22)

i2c = I2C(sda=sda_pin, scl=scl_pin)
devices = i2c.scan()
if not devices:
    print("No devices!")
    sys.exit(1)

print([hex(d) for d in devices])

Expectation:

The above main.py should print [‘0x6d’, ‘0x48’] where the 0x48 is the temp sensor and the 0x6d is the relay.

Actual:

The output is always [‘0x48’]

Things I’ve tried:

  1. Connecting only the relay board to QWIIC (empty output from main.py)

  2. Connecting the 2 boards in a different order on the QWIIC bus (same result)

  3. Connecting only the temp board (as a control) ( result is still [‘0x48’])

  4. Using diff. 12V and 9V supplies to the relay board (same results)

2

My only advice would be to try using the Quad Relay win a known good configuration like on an Uno first to make sure it’s functional. If it’s not working there, you’d need to initiate a replacement.

3

Thanks, Chris. I am just getting into working with MCUs and the hardware list in my post is all I own. I’m not sure I want to have to buy additional hardware just to confirm that the relay board is defective or not.

Is there any sort of test or procedure I could try to confirm that the board is defective?

Thanks,

Don

4

Oh, also, I did come across a posting somewhere on this forum (can’t seem to find it now) that the quad relay board is missing (by design, apparently?) the required pull-up resistors on the I2C lines. I have some 10K resistors, but I do not want to attempt to solder those on and void any warranty that might be available to me. My understanding is that the pull-ups that are on the temperature sensor would provide the necessary pull-ups, so I am left thinking that the board is indeed defective.

5

I purchased and added an OLED display module (LCD-17153) into the mix. Now my results are that only the temp sensor is detected and the quad relay and display never are (in various combinations and configurations). This leads me to believe that maybe this is a power issue or something amiss with the ESP32 board?

6

Sounds like there’s something wrong with your relay board.

If you purchased the relay board directly off our website, just [fill in the form on this page with your order number and the URL to this forum post and we can replace it for you.

If you purchased from a distributor or Amazon you will need to let them know you have a defective product and arrange with them for an exchange.](Return Policy - SparkFun Electronics)