VL53L5CX-SATEL won't respond to I2C?

CSkil.1 · ‎2023-10-09

I'm trying to get the VL53L5CX-SATEL to talk to a microcontroller.

The lines are connected as follows

INT	Floating
I2C_RST	22K pull down
SDA	MCU SDA Pin with 2.2K pull up to 3.3v
SCL	MCU SCL Pin with 2.2K pull up to 3.3v
LPn	22K pull up to IOVDD (3.3V)
PWREN	22K pull up to AVDD (5V)
AVDD	5V
IOVDD	3.3V
GND	GND

When I try to send a write command, the device does not ACK the address (0x52). Can anyone see what I'm doing wrong?

CSkil.1 · ‎2023-10-09

OK, the I2C driver in the MCU was shifting the address left by 1 so the address was being sent as 0xA4 as seen in the trace. With the address corrected it works. Thanks all.

View solution in original post

Anne BIGOT · ‎2023-10-09

Hello,

Are you using the SATEL itself or the breakout board ?

It will change in the fact that the SATEL has already the pull ups while the breakout board doesn't.

Moreover ST suggests to put a pull-up between 2.2 and 4.7 k and not much than 4.7. (check AN5717)
Regards,

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CSkil.1 · ‎2023-10-09

OK, the I2C driver in the MCU was shifting the address left by 1 so the address was being sent as 0xA4 as seen in the trace. With the address corrected it works. Thanks all.

asko-k · ‎2024-08-26

@Anne BIGOT wrote:
[...] the SATEL has already the pull ups while the breakout board doesn't.
Moreover ST suggests to put a pull-up between 2.2 and 4.7 k and not much than 4.7. (check AN5717)
Regards,

Let me note that in the schematics of PCB4109A variant, all the pull-up and pull-down resistors are on the side of the "breakout board" (the little board). Thus, it seems to me very few if any resistors are needed by me, to have the board functioning.

Disclaimer: I am still working on getting the I2C comms established.