CYW43438 on RPI, not able to communicate over UART to enable BT

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Anonymous
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Hi all,

I am using a Wifi/BT module containing CYW43438 connected to a RPI3CM. Wifi Works fine, BT no.

I connected only Rx TX to RPI and starting hciattach on raspbian it goes in timeout:

hciattach /dev/ttyAMA0 bcm43xx-3wire 115200 noflow -

bcm43xx_init

Initialization timed out.

On the module RTS is float CTS is pulldown.

Looking at the signals and decoding them, I see that the chip reply to the first command but not to the second one asking the chip name.

0x01 0x03 0x0C 0x00          <-- reset chip          

0x04 0x0E 0x04 0x01 0x03 0x0C 0x00

0x01 0x14 0x0C 0x00          <-- asking for chip name

     -- no answer

Can you help me to understand why the communication doesn't continue in order to setup the device completely?

Linux raspberrypi 4.14.68-v7+

bluez/stable,now 5.43-2+rpt2+deb9u2

bluez-firmware/stable,now 1.2-3+rpt6

pi-bluetooth/stable,now 0.1.9

My impression is that H% 3wire  uart it is not properly configured and the chip look at the CTS signal anyway.

If I remove the pulldown on CTS, disappear also the fir reply to the reset command. So it seems the chip take the CTS status into account.

But I would like to use it managing only Rx and TX

Thanks

Mimmo

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1 Solution
AnjanaM_61
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5 comments on KBA First comment on KBA 5 questions asked

Could you please confirm which UART are using? the miniUart or the main PL011 uart (https://www.raspberrypi.org/documentation/configuration/uart.md) ?

If the miniUart it probably won't work.

Secondly, i'd suggest trying it with CTS and RTS connected, as this is how it is configured on Pi3, Pi3B+, Pi0W

Let us know if these changes make any difference.

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1 Reply
AnjanaM_61
Moderator
Moderator
Moderator
5 comments on KBA First comment on KBA 5 questions asked

Could you please confirm which UART are using? the miniUart or the main PL011 uart (https://www.raspberrypi.org/documentation/configuration/uart.md) ?

If the miniUart it probably won't work.

Secondly, i'd suggest trying it with CTS and RTS connected, as this is how it is configured on Pi3, Pi3B+, Pi0W

Let us know if these changes make any difference.