I2C interface L89HB not working

IoT Modules GNSS Module
1

Hello ,

I am working on a L89HB module with the following firmware version L89HBNR01A01S .
The module is not responding with ACK’s while writing with to the module using addresses 0x50 , 0x54 or 0x58 . I am measuring with an oscilloscope and the I2C signals are OK . I am sharing the I2C bus with another device and that one is working good on address 0x43 .

I read on the forum that a firmware version with a SC suffix supports I2C interface.

Quectel , can you help with a firmware version that support I2C ??

Thanks

rschoop

2

Hi @rschoop
Please use the “$PQTMVERNO*58” command to check the version of the module and let me know.

3

Hi George ,

I get the following string : $PQTMVERNO,L89HBNR01A01S,2023/01/10,15:05:20*3D

Please also give me some instructions on how to flash the module . It here a flash tool ??

Thanks,

rschoop

4

Hi @rschoop
L89HBNR01A01S supports I2C and UART communications.
Please provide your email address and I will send you the relevant information via email.
The serial port tool we commonly use is QGNSS. QGNSS tool download link: QGNSS_V1.10_CN | 移远通信 (quectel.com.cn)

5

Hi George ,

You can send me the info at moreno3977@gmail.com

Thanks,
rschoop

6

Hi George ,

Actually I am using QGNSS v2.0 already .

I also have this documentation : L89 R2.0&LC29H Series&LC79H (AL) I2C application note . But somehow the I2C interface is not working . Module is not replying to with ACK’s .

Thanks,
Ramphis

7

Hello George , I have not received the email with info yet.
Please , can you send me this info ?

Thanks,
rschoop

8

Hi @rschoop

  1. L89HBNR01A01S is the latest software version, and this version supports I2C communication, so no information was sent to you via email.
  2. You refer to the L89 R2.0&LC29H Series&LC79H (AL) I2C application note document, but the module does not communicate successfully. Can you take a picture of your hardware? Please describe how you operate it? What is the main control (MCU) used?
9

Hello George ,

I am using a ARM microcontroller , max32650 . I am sharing the I2C bus with another component with address 0x43 and that one is working properly. The GNSS module is behind a level translator . I double check all the pins , and pcb routing . Everything is OK . See picture 1 below .

I am just scanning the I2C bus with a write it . 10 bits : 1 start, 7-bit address , 1 write bit and 1 ACK/ NACK bit . On the scope you can also see the stop bit after the ACK/NACK .

Picture 2 you can see the clock SCL as reference .

Picture 3 , you can see the device with address 0x43 with the ACK working , see red arrow .

Picture 4 , you can see the GNSS without the ACK or NACK on address 0x50 .

Picture 5 , you can see a measurement directly on the SDA pin of the GNSS . No ACK .

Can you check for me ?

Thanks,
rschoop

PS. Forum let me put only one pic in the post . I will send the others in other posts.

Picture 1

20240923_210900
20240923_2109001920×3412 537 KB

10

Hi George , see pdf file with pics
thanks

gnss.pdf (767.6 KB)

11

Hi @rschoop
From the figure, we can see that the voltage on the SDA pin is about 3.0V（picture5）, and the voltage on the SCL pin is about 1.8V（picture4）. The current problem should be a voltage mismatch. Please add a voltage conversion chip and synchronize the voltages before testing.

12

Hi George ,

If you check the picture of board, you see that U16 is a level translator . You can see the SCL and SDA pins are connected to it for the 3.0V and at the other side it is 1.8V for the microcontroller . Picture 5 is in the 3.0V domain and picture 4 is in the 1.8V domain.

You can see that the GNSS module does not give ACK 's.

Please check this post L96 GPS I2C problem

maybe the firmware need to have a SC suffix to support I2C ??

Thanks,
rschoop

13

Hello George ,

Do you have more information or hint for solution this issue ?

Thanks,
rschoop

14

Hi @rschoop
L89HBNR01A01S supports I2C and does not have a software version with an SC suffix.
L89HBNR01A01S is the latest software version, and there is no updated software version.
I have sent you the relevant information via email, please check.