AFE4490SPO2EVM: Afe4490spo2evm use with external microcontroller

Hamza Syed

Part Number: AFE4490SPO2EVM
Other Parts Discussed in Thread: AFE4490,

Hi, I want to use the afe4490spo2evm with an external microcontroller. I have problem with receiving the SPI data. I first write to the Control0 register to enable SPI read and then I read another register I have tried reading all the registers but there is no reply from afe4490.

I have removed the resistors which are used for SPI and DRDY , AFE PDN and RESET which connects to onboard microcontroller as mentioned in one of the TI forums.

I am using NRF52833 DK board whose lines voltage level is 3V.

Please let me know what could be the problem. I am receiving the DRDY interrupts on oscilloscope. Also if I connect the PDN pin to nrf it stops giving pulses on DRDY pin no matter PDN high or low when I connect the PDN pin the pulses stops.

over 1 year ago

0 Nick Zahabizadeh over 1 year ago

TI__Expert 4134 points

Hi Hamza,

Welcome to the TI E2E forums.

Could you share some more details on how you've connected your MCU to the AFE board?

Kind regards,
Nick Z

0 Hamza Syed over 1 year ago in reply to Nick Zahabizadeh

Prodigy 10 points

I removed these resistors and connected jumper wire to the AFE4490 side. Which I then connected with my nrf board.

0 Hamza Syed over 1 year ago in reply to Hamza Syed

Prodigy 10 points

as also mentioned in the data sheet

0 Hamza Syed over 1 year ago in reply to Hamza Syed

Prodigy 10 points

I have tested my SPI code with the loop back test and it's working fine. I have used 4MHz frequency.

+1 Nick Zahabizadeh over 1 year ago in reply to Hamza Syed

TI__Expert 4134 points

Hello Hamza,

It sounds like you may not be writing to / reading from SPI correctly. I recommend you double check your SPI signal generation on your MCU with section "8.5: Programming" on the AFE4490 datasheet alongside probing your SPI signal generation via scope to validate.

Kind regards,
Nick Z

0 Hamza Syed over 1 year ago in reply to Nick Zahabizadeh

Prodigy 10 points

Thank you Nck Zahabizade.

Yeah, you are right, the chip select pin was not working correctly. I programmed it as an active high pin that's why it was not working. After I configured it as active low pin then it started replying.

0 Nick Zahabizadeh over 1 year ago in reply to Hamza Syed

TI__Expert 4134 points

Hi Hamza,

I'm glad that the problem got resolved. Since the challenge is solved I'll be closing this thread.

To reopen this thread, just reply to this post. For further support, make a new thread.

Kind regards,
Nick Z

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AFE4490SPO2EVM: Afe4490spo2evm use with external microcontroller