Equation result is not as expected

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 23:36:00 GMT

Thank you very much for your help. I think I should try this twi driver in blocking mode. That sounds very robust. Thank you.

RE: Equation result is not as expected

RK — Thu, 23 Nov 2017 23:28:02 GMT

so wait for the RX event then before continuing, or use the twi driver which does all this for you.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 23:26:33 GMT

No sorry I am not using this Code what you think. I coded my own little driver with all registers which are explained in the TWIM chapter ("33 TWIM — I2C compatible two-wire interface master with EasyDMA") in this document: "nRF52832 Product Specification v1.4".

RE: Equation result is not as expected

RK — Thu, 23 Nov 2017 23:10:54 GMT

You're clearly using the TWIM driver, so go and read the chapter about the TWIM driver in 'Hardware Drivers' which explains the code you're using.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 23:04:02 GMT

Thank you for your answer. Ok, of course I am going to read more about twi handler. But I am using TWIM0 (Twi Master) at the moment. And in this chapter of NRF52832 says nothing about Blocking Mode or something.

RE: Equation result is not as expected

RK — Thu, 23 Nov 2017 22:59:13 GMT

please go and read the documentation on the twi handler you're using, it's very comprehensive and will tell you all about how to initialize the driver in blocking as opposed to non-blocking mode.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 22:57:29 GMT

Yes that seems to be the explanation why the data is not available.

But how can I know when the data is available? How can I use this feature what you call "the blocking mode" ?

RE: Equation result is not as expected

RK — Thu, 23 Nov 2017 20:57:42 GMT

fairly obvious guess is that you've enabled the TWIM in non-blocking mode giving it a callback however you're using it as if it were in blocking mode in that code expecting the data to be available as soon as the twim rx call completes.

That also explains why the debugger shows the values equal because, by the time you get to look at them in the debugger, the data has been transferred.

If you want blocking mode then use that, if you want callback mode, put your code in the callback.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 19:46:26 GMT

And the equation also works If I add a whait time of 5ms before the if case code segment. At the moment I dont understand why I have to do this.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 19:36:48 GMT

Now I made another discovery. If I stop the running with a debug mark at this point: if (return_eok == 0)

and after this debug mark I start running again. The equation is working.

If I dont have this debug mark at this point and I only have a debug-mark after the code segment I gave you the equation is not working.

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 17:01:43 GMT

No. I am not working with the official SDK Board. I have built my own Prototype/Evaluation Board. So I am going to check the SDK examples configruation.

What I did: I took the default configuration for the NRF52832 in the Segger Studio IDE.

What I discovered is that it doesnt matter which value I give this equation. Its always true. So its like the Mikrocontroller doesnt get this right value for the equation.

RE: Equation result is not as expected

MartinBL — Thu, 23 Nov 2017 16:47:05 GMT

Are you using the same compiler settings as we do in our default SDK examples?

RE: Equation result is not as expected

Fifty1 — Thu, 23 Nov 2017 15:57:56 GMT

Yes its very strange.

I am reading the DeviceID from an accelerator sensor. I tried several solutions (equation with uint8_t variable, with Makro, with hexvalue). Nothing is working. CPU is going always in this if case.

In Segger IDE it says that deviceid is the same value (0x33) as the Makro or other variable.

  uint8_t deviceid = 0;

    // read device ID
        if ((nrf52810_drv_twim0_rx_data((uint8_t) LIS3DH_I2C_DEVICE_ADDRESS, (uint8_t) WHO_AM_I, &deviceid, sizeof(deviceid))) != 0)
        {
           return_eok |= ERROR_BIT_0;
        }
            
        if (return_eok == 0)
        {
           if (deviceid != LIS3DH_VALUE_DEVID)
           {
              return_eok |= ERROR_BIT_1;
           }
        }

Maybe there is something wrong with Compiler Settings or something like this. Its like I see in Segger IDE not the same what the Mikrocontroller gets from the compiler (as assembler code).

RE: Equation result is not as expected

MartinBL — Thu, 23 Nov 2017 13:27:29 GMT

Thats strange. Are you able to post more of your code?