X NUCLEO 53L7A1 with 4 SATEL-VL53L7A breakout boards

[SelimMuhammed]

Hi, ST
Now I followed the X-NUCLEO-53L7A1 User guide connection for the SATEL-VL53L7A TOF breakout boards LEFT and RIGHT Connection as Shown in the attached image and it worked well, even if there are 2.2K pull up resistors for each sensor which makes the equivalent pull up resistor = 2.2K / 3 but I worked well till I also added another 2 SATEL-VL53L7A TOF breakout boards in addition to 1 Barometer Sensor breakout board which has the part number STEVAL-MKI225A it started to make undefined behaviors such as (TOF sensors Initialization fault, Barometer Sensor Initialization fault, Barometer wrong readings).
So, could this problem caused by another 2 SATEL-VL53L7A TOF breakout boards with there Pull-up resistors?
and If yes, Should I remove the 0 Ohm resistors on solder bridges to disconnect the pull-up resistors from each sensor as shown in the second attached image?

[db16122]

it seems the X-NUCLEO-53L7A1 is for Time-of-Flight 8x8 multizone ranging sensor with 90° FoV expansion board based on the VL53L7CX. If you put STEVAL-MKI225A  on the board, the compatibility could be a probiem. Do you modify the driver code? It seems the schematics for both device is also different, not sure why do you want to put 2pcs STEVAL-MKI225A + 1pc SATEL-VL53L7A

 

[SelimMuhammed]

Hi, db16122

I meant here that I have added another 2 SATEL-VL53L7A and one STEVAL-MKI225A (which has no Pullup resistors) so my set up now contains: 5x TOF sensors (1x X-NUCLEO-53L7A1 + 4x SATEL-VL53L7A) and 1x Barometer Sensor ( STEVAL-MKI225A ) and I want to test them all together.

[db16122]

From the block diagram, it seems the U2, J5 Right and J5 Left share the same I2C bus. Not sure they can test together or not...

[SelimMuhammed]

I followed the sequence of I2C Set address using the set_i2c_address() API that mentioned in the UM3038 User manual for Ultra Lite Driver (ULD) APIs and It worked with both Left and right sensors

[db16122]

I see. So How about another 2 pcs TOF sensors? It seems you can put 5 TOF on the board plus another Barometer sensor. That is 6 sensor module. Not sure the module can fit 6 module all in one X-NUCLEO-53L7A1 module

[Bin]

Hi:

The X-NUCLEO-53L7A1 is designed for center, left and right total 3 L7 tof sensors.

if you want to connect more, you can conduct secondary development based on the ioc file in the software package. That is to say, the pin required for the additional TOF sensor should be defined and hardware connected by finding suitable pins from the unused pins of STM32F401 ARDUINO. After generating the source code, and set correct I2C address, then you can try running it. Thank you~

Best Regards,

Bin FAN

[SelimMuhammed]

​Hi @Bin,
I have already connected the other L7 TOF sensors to the same I2C BUS an followed the same configurations in the SW Package and they worked after setting the I2C Addresses for each one 
My question is about the connected pullups for each sensor board would they affect the I2C communication as the communication fails when I add the Barometer to the same Bus?

 

[Zhiyuan.Han]

Hi,

 

From your issue description, it should be related to the I2C pull-ups as there are pull-up on the X-NUCLEO-53L7A1, and also pull-ups on the SATEL-VL53L7A, the more STTEL-VL53L7A connected, the less total resistor value as you calculated. and plus the pull-ups on STEVAL-MKI225A (if have), this will make the total resistor value quite less. 
The suggestion I would propose is measuring the I2C signal quality with the oscilloscope, if too much noise on I2C bus, try to remove the SB5 and SB7 step by step. 

 

 

BR

Zhiyuan.Han