sensing temperature with a thermocouple / thermocouple

[jaraya]

hello, testing the spi examples of SDK16.0.0 I was trying to read a type k thermocouple with a max31856 on the nRF52840dk board, I made the connections of ss, sck, mosi, miso. The problem is that I don't get thermocouple values, is there another way to read this type of sendor with the nRF52840dk board?

[ovrebekk]

Hi

Have you made sure to configure the SPI in the nRF52840 with the right mode and frequency to work with your sensor?

Have you tried to probe the SPI lines with a scope or logic analyzer to verify that the communication looks OK?

Best regards
Torbjørn

[jaraya]

I have another doubt, to read a type K thermocouple with a max31856 through SPI, which example could be useful to read the data sent by the sensor?

[ovrebekk]

Hi

We don't have any examples for this type of sensor unfortunately. 

Either you would have to find some non-nordic example and adapt it to the nRF52840, or implement something from scratch based on the MAX31856 datasheet. 

Best regards
Torbjørn

[jaraya]

Hello, I found this example not Nordic, but I am getting complicated to adapt it, do you have any tips for it?

https://www.maximintegrated.com/en/products/sensors/MAX31856.html/tb_tab2

[ovrebekk]

Hi 

Have you looked into this example?

https://github.com/engineertype/MAX31856/tree/master/MAX31856

It looks pretty straight forward, but you will need to replace the GPIO and SPI functions with the Nordic ones, and implement a function based C interface rather than a class based C++ interface. 

Best regards
Torbjørn

[jaraya]

Another question regarding the spi or spim example code, how can I pass it from TEST_STRING to show me the values given by the miso pin?

[ovrebekk]

Hi 

Sorry for the late response, I have been out of office for the last month or so. 

Do you still need help with this?

The incoming data is stored in the m_rx_buf buffer, which is written to the log inside the spi_event_handler() function. Is this not what you are looking for?

Best regards
Torbjørn