Troubleshooting - Micropressure Sensor Not Detected

Sensors Environmental
1

Looking for some suggestions on troubleshooting connections between the Sparkfun Micropressure Sensor (SEN-16476) and the Sparkfun Thing Plus ESP32 WROOM USB-C (WRL-20168). I purchased these intending to follow along with the Atmospheric Pressure guide (Measuring Height with Atmospheric Pressure - SparkFun Learn).

Hardware setup is identical to the guide: QWIIC cable connecting the Thing Plus with the Sensor. Thing Plus powered over USB. Software is using Arduino IDE 2.3.2, with Sparkfun MicroPressure Library v1.0.1 included in sketches.

First attempt used the Height Demo code found in the guide. When connected, the power LED on both the Thing Plus and the board are lit. When run, the Thing Plus returns:

19:00:12.558 -> ets Jul 29 2019 12:21:46
19:00:12.558 -> 
19:00:12.558 -> rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
19:00:12.605 -> configsip: 0, SPIWP:0xee
19:00:12.605 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
19:00:12.605 -> mode:DIO, clock div:1
19:00:12.605 -> load:0x3fff0018,len:4
19:00:12.605 -> load:0x3fff001c,len:1044
19:00:12.605 -> load:0x40078000,len:8896
19:00:12.605 -> load:0x40080400,len:5816
19:00:12.605 -> entry 0x400806ac
19:00:12.731 -> MicroPressure height demo begin!
19:00:12.731 -> Cannot connect to MicroPressure sensor.

In all configurations I can think of, the MicroPressure sensor remains undetectable to the ThingPlus.

Troubleshooting So Far:

  • Replacement ThingPlus cannot detect MicroPressure sensor.
  • Replacement MicroPressure sensor is undetected by either ThingPlus.
  • Six different QWIIC cables, no change in output message.
  • Attempted connections to each QWIIC port on the sensor.
  • Different power sources: PC connected or appropriate voltage battery connected.
  • Alternative sketch from the MicroPressure sensor hookup guide, no connection to sensor.
  • Manually specifying the address (0x18, Wire1) for the MicroPressure Sensor as per its manual.
  • An I2C scanner script detects no connected devices.
  • No change between version 1.0.0 and 1.0.1 of SparkFun MicroPressure Library
  • Blink Demo on each SparkFun Thing Plus works - boards run sketches fine.
  • Full reinstall of Arduino IDE on main computer, and attempted sketch compiling and upload on second computer.

I feel like I must be missing something fundamental for the ThingPlus to not detect the sensor at all in any of these combinations. Would appreciate any ideas!

2

It looks like the demo tries to use Wire, not Wire1 Measuring Height with Atmospheric Pressure - SparkFun Learn

How long are your qwiic cables? Try disabling the i2c pull up resistors by cutting the trace on the back of the board and re-attempt (easily reversible by replacing a solder blob)

3

Thanks for replying. I tried the Example Script in the Micropressure Library with specifying (0x18, Wire) as well as (0x18, Wire1) and there was no change.

The cables are 5, 10 and 15cm long.

With traces cut on I2C pull-up resistors, no change in board being able to see the sensor.

4

Hi

You tried a lot but still not get the right results.

Your program never came out from this loop:
if (!mpr.begin()) {
Serial.println(“Cannot connect to MicroPressure sensor.”);
while (1);
}

because mpr.begin() never returned false or 0.
This is a kind of harware lock.

Have you checked the pin assignments in the code:
There is seems right pin connection issue:

#define EOC_PIN  -1
#define RST_PIN  -1
#define MIN_PSI   0
#define MAX_PSI   25

SparkFun_MicroPressure mpr(EOC_PIN, RST_PIN, MIN_PSI, MAX_PSI);

Specially check these two pin signals: 
#define EOC_PIN  -1
#define RST_PIN  -1
1 Like