SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

xuezhi_zed — Wed, 19 Jun 2024 09:02:28 GMT

Hi, I am designing nrf52840 with MAX86141. Want to ask if can get your help or do you plan to opensource your code for this?

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

Kalrz — Wed, 07 Apr 2021 10:28:36 GMT

hallo awneil,

thanks for the reply. The problem is solved.

The issue was with connection. A jumper used for MISO was defective. So it failed to produce the signal at the input of logic level shifter.

I am facing an other issue with the software. I will create a new ticket for that.

Thank you for the help.

best regards,

Karlz

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

awneil — Wed, 07 Apr 2021 08:20:23 GMT

Please post a schematic of your complete setup.

[quote userid="101266" url="~/f/nordic-q-a/73646/spi-communication-between-nrf52840dk-master-and-max86140-slave-no-signal-in-miso-line"]There is no or too little (unexpected) activity in the MISO line[/quote]

MISO is driven by the slave - so what happens if you disconnect MISO at the slave, and just monitor it at the slave?

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

Kalrz — Wed, 07 Apr 2021 08:06:13 GMT

Hallo,

Here is the schematics of the setup.

Please note that the entire schematics of the sensor board can be found in datasheet of EVM (Page number 28). The sensor board consist of an extra accelerometer which we are not accessing through spi. We are trying to communicate with the MAX86141 module alone.

This is the image of the sensor taken and merged from either side.

In between the sensor and nrf52840DK, we are using a logic level shifter shown in the schematics. At the moment we are using DIP converter and breadboard for the connections. As you can see from the image below, we are using a FPC to dip convertor in order to access the SPI pins from the sensor board.

I hope its clear now. Please let me know in case of any confusions.

regards,

Karlz

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

Kalrz — Tue, 06 Apr 2021 18:29:23 GMT

Hallo,

[quote userid="6462" url="~/f/nordic-q-a/73646/spi-communication-between-nrf52840dk-master-and-max86140-slave-no-signal-in-miso-line/303271#303271"]Can you not get a proper screenshot from your logic analyser (rather than taking a photo) ?[/quote]

Unfortunately, that is not possible. It is a very old logic analyzer. It doesn't have an option for screenshots or USB.

[quote userid="6462" url="~/f/nordic-q-a/73646/spi-communication-between-nrf52840dk-master-and-max86140-slave-no-signal-in-miso-line/303271#303271"]Please post a schematic of your setup[/quote]

I will post the schematics of the setup and will try to capture better images tomorrow.

Thank you

RE: SPI communication between nrf52840dk (Master) and MAX86140 (slave) / No signal in MISO line

awneil — Tue, 06 Apr 2021 16:03:56 GMT

Please post a schematic of your setup. Also some good, clear, in-focus photographs.

Can you not get a proper screenshot from your logic analyser (rather than taking a photo) ?