topic Re: KM34Z50M connectivity problem in Kinetis Microcontrollers

KM34Z50M connectivity problem

harishvenkatach — Thu, 02 Jul 2015 16:21:48 GMT

Hi,

I am trying to connect the Freescale KM34Z50M to Cirrus Logic CDB5480 board. The CDB senses temperature and the KM controls a relay based on the temperature readings. The CDB senses the room temperature properly, but when I connect the KM TWR to it, the readings somehow get corrupted. I connect the pins 17,18,19,20 of SPI to the RX,TX,CLK and CS of the CDB respectively. Can anyone explain why this happens?

Thanks in advance.

Re: KM34Z50M connectivity problem

Hui_Ma — Fri, 03 Jul 2015 02:44:45 GMT

Hi,

Could you provide more detailed info about the issue?

From the description, there without problem with SPI connection.

If the KM34 could read out the data from CDB5480?

If the KM34 could not get the data from CDB5480 board stably during the whole temperature range?

Thank you for the attention.

Have a great day,
Ma Hui

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Re: KM34Z50M connectivity problem

harishvenkatach — Mon, 06 Jul 2015 13:49:45 GMT

Hi,

When I use the CDB5480 board as a standalone, it is able to measure the room temperature. But when I connect the SPI ports with the TWR, it throws up strange errors, likely due to corruption of the registers.

Hoping for a solution.

Regards,

Harish Venkatachalam

Re: KM34Z50M connectivity problem

Hui_Ma — Tue, 07 Jul 2015 08:42:39 GMT

Hi,

I checked the CDB5480 board, there with a C8051F342 MCU connects with CS5480 chip with SPI.

If you could try to remove the resistors of R34,R35,R36,R37&R38.

After that,please try to use KM34 board connects with the CDB5480 board and check if it works or not.

Have a great day,
Ma Hui

Re: KM34Z50M connectivity problem

Hui_Ma — Tue, 07 Jul 2015 08:45:02 GMT

BTW: I checked CS5480 datasheet, the Max. SPI clock is 2MHz.

Please check if KM34 SPI clock setting if in range of 2MHz.

Wish it helps.

Re: KM34Z50M connectivity problem

harishvenkatach — Tue, 07 Jul 2015 14:21:41 GMT

Hi Hui,

Thanks for replying. The resistors are soldered onto the board. How do we remove the resistors?

Regards,

Harish Venkatachalam

Re: KM34Z50M connectivity problem

Hui_Ma — Wed, 08 Jul 2015 04:22:07 GMT

Hi,

I don't have that board. I think using an electric soldering iron could do that .

Have a great day,
Ma Hui

Re: KM34Z50M connectivity problem

harishvenkatach — Wed, 08 Jul 2015 16:12:59 GMT

Hi Hui,

Thanks for your help. I appreciate it.

Regards,

Harish Venkatachalam