How to read two I2C (Having Same Address) sensors using NRF52840

RE: How to read two I2C (Having Same Address) sensors using NRF52840

Turbo J — Sun, 26 Nov 2023 09:31:51 GMT

Bad idea. These require quite a bit of bus bandwidth in order to read all the FIFO data.

Use a set of pins for each sensor, the NRF52840 has two TWIM uinits. That allows you to read the data in parallel.

RE: How to read two I2C (Having Same Address) sensors using NRF52840

Khalil Ahmad — Sun, 26 Nov 2023 08:33:38 GMT

Yes, Interrupts are routed to different pins on the NRF52840.

RE: How to read two I2C (Having Same Address) sensors using NRF52840

Sigurd Hellesvik — Wed, 22 Nov 2023 15:06:23 GMT

[quote user="Khalil Ahmad"]My Question is... If nothing works then what happened now ?? Means to say as both sensors are connected with same address (The purpose of using two sensors to locate the vein to check the pulse... any of the sensor will find it and give the result). Its mean both sensors will send the data on single address. [/quote]

Could look like that. I assume that you have no way to disconnect one of the sensors from power?

[quote user="Khalil Ahmad"]As per the proximity enable option. Lets assume if any of the sensor (the other will be in the idle mode) find the vein, so I will get the data ?????[/quote]

Are the sensors interrupts routed to different pins on the nRF?

[quote user="Khalil Ahmad"] Lets assume if any of the sensor (the other will be in the idle mode) find the vein, so I will get the data ?????[/quote]

Well, if I2C wakes up the sensor as well, this will not work. I struggle to find if this is the case from the datasheet or not.

RE: How to read two I2C (Having Same Address) sensors using NRF52840

Khalil Ahmad — Mon, 20 Nov 2023 13:06:28 GMT

This is the link of the datasheet

Data Sheets-max86916

I read the information provided in the link. as per my custom PCB both sensors are connected on the same pin but their interrupt is at different pins. I checked the PCB and

1 - Its not possible to make any changes physically to disconnect the pins and connect to other pins

2 - There is no information for selecting different address

My Question is... If nothing works then what happened now ?? Means to say as both sensors are connected with same address (The purpose of using two sensors to locate the vein to check the pulse... any of the sensor will find it and give the result). Its mean both sensors will send the data on single address.

After reading the Data Sheet I came to know that there is proximity option (which means when its enabled, the sensor will start its operation when detects the pulse)

and

As per the proximity enable option. Lets assume if any of the sensor (the other will be in the idle mode) find the vein, so I will get the data ?????

RE: How to read two I2C (Having Same Address) sensors using NRF52840

Sigurd Hellesvik — Mon, 20 Nov 2023 12:05:29 GMT

Hi,
See https://learn.adafruit.com/working-with-multiple-i2c-devices/overview for a guide on multiple I2C devices with the same address

Often, I2C slave ICs have a pin which can toggle between giving it different addresses.
For example from MC3479:

Regards,
Sigurd Hellesvik