Hello everyone, I have a question regarding I2C and specifically used for CCS811, but it would apply to all applications. So I am using the library provided here and I am trying to make my CCS811 on Air Quality click 3 work. The library provides an init() functions which checks the hardware and r…

Hi Chris, The 0x81 looks like a device ID. However on first look I see nothing wrong from you but maybe you can try to check if ACKs, by the write and read methods, were returned. printf( (i2c.write(addr, write,1))==0 ? "ACK\n" : "NAK\n"); I am not sure but maybe in this library is a mis…

Hello Jan, Thank you very much for the reply, I will try your suggestion regarding the ACKs and get back to you. Also regarding 0x81, yes the init() function checks the device ID and returns success, so I assume I am communicating with the chip on some level. I have actually tried using the secon…

Hi again, add to I2C basics, I hope it is not problem in this case, usually a common problem is missing or not insufficient resistance for pull-ups of the I2C. Some times are solved by internal on-chip pull-ups, some time some modules already have it, but usually it is need to be solved by the user…

Hello, I am finally getting somewhere but I am not using libraries any more and writing it from scratch. I was able to read the chip ID correctly! I have another quite basic question. Say slave address 0xEC and register address I am trying to reach is 0x72 and I want to set that to 0x1 would I do…

Hi, it looks ok and it depends on the application but a model of what you need to hold in this aplication, you can found in the datasheet, page 13. BR, Jan

Great thank you so much, it all makes sense now and I have communication with the chip. You have been far more helpful than the documentation I must say, cheers! Chris

You are welcome I’m glad you achieved what you wanted. Good luck with your project Jan

Good morning, One last question and I think I am set. With reference to page 22 of the datasheet, the firmware register is two bytes, byte0 and byte1. In which order are bytes saved in the array? char wE[1]; wE[0]=0x24; char rE[2]; i2c.write(addr,wE,1); i2c.read(addr,rE,2); pc.printf("Byte0: %x,…

Hello, I saw your post before edit. Are you sure, you are read a right register? You wrote about errors but the error register has only one byte on the address 0xE0. Your address register is for firmware version, according to page 22 of datasheet. However, I do not know, but logic say me yes, you…

Hello, Yes I realised I was using the wrong register. Since the error is one byte I get it to be 0x00 correctly, but I was still wondering about the order that data is saved in the array. Great thanks once again :smiley:

I2C with CCS811 basic question

Mbed OS

JohnnyK (Jan Kamidra) May 13, 2020, 10:44am 17

I am not sure what you mean but this will help you?

Topic		Replies	Views
Custom F446RE board fails with both reads and writes to I2C Custom and community boards mbed_os , stmicroelectronics , nucleo-f446re	9	274	January 9, 2024
I2C slave does not work Mbed OS	0	310	July 3, 2020
What do the I2C functions read and write exactly do Mbed OS	3	483	March 15, 2020
I2C bus not working on Nucleo boards Mbed OS	6	1220	May 27, 2021
Problems about using I2C.h Mbed OS	6	314	January 19, 2024

I2C with CCS811 basic question

Related topics