spi Miso problem

RE: spi Miso problem

Nero — Thu, 21 Dec 2017 14:23:38 GMT

@Jørgen I feel like I send ORC byte in writing, because when reading I always read ORC octect in the register

RE: spi Miso problem

Nero — Thu, 21 Dec 2017 10:02:10 GMT

the problem is that I can read the default values of the registers, but when I try to write and read the register at the same time but I encounter a problem (a byte of ORC bits which is added during the write) this a example CTRL_REG1(0x20)

Write funcion Capture1.PNG Read function Capture.PNG

Thanks!

RE: spi Miso problem

Jørgen Holmefjord — Wed, 20 Dec 2017 14:45:03 GMT

I see. Which function call are you using for sending/receiving the WHO_AM_I command? It is not clear from you code, as there is a lot of function calls commented out.

RE: spi Miso problem

Nero — Wed, 20 Dec 2017 14:29:15 GMT

yes , 0x8F because in read mode bit 0 will be 1 ( Read, 1 = No Addr Inc, 001111 = WhoAmI Reg )

RE: spi Miso problem

Jørgen Holmefjord — Wed, 20 Dec 2017 13:40:12 GMT

Fro your screenshot it seems like you are writing 0x8F, but the datasheet of the LIS2DE12 device say that the WHO_AM_I register is located in address 0x0F. Are you sure you are sending the correct command? Please post code snippets showing what you are doing.

RE: spi Miso problem

Nero — Wed, 20 Dec 2017 13:26:31 GMT

I want to read the registerWho I am

RE: spi Miso problem

Jørgen Holmefjord — Wed, 20 Dec 2017 10:39:15 GMT

What do you expect on the MISO line? If you are doing a read operation, I would expect the data on MISO line to be don't-care while the command is transmitted, and the data afterwards to be what you are requesting. If you do a write operation, all data on MISO will be don't care.