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TMS320C5515EVM with ECG and CC2540 BLE

Other Parts Discussed in Thread: CC2540, ADS1298

Hello,

I've a 5515evm running well with the ADS1298. Next I used the SmartRF with cc2540/41 to create a bi-directional serial connection. This works fine as well. However it seems to me that, checking the schematics (5515EVM and CC2540EM), the Rx (P0.2) and Tx(P0.3) are in conflict with the Rx/Tx signals on the 5515EVM module!  Can someone confirm this? Before I start patching!

kind regards,

Laurent

  • I am not quite understand your issue. Do you saying that the C5515EVM is working fine with the CC2540EM but you are trying to confirm the schematic connection. Maybe we can refer to UART DB9 connector pin #. As for C5515EVM, UART_TX is on pin 3 and UART_RX is on pin 2 of DB9 male connector. I have not found the CC2540EM schematic yet.

    Regards.

  • Hello Steve,

    thanks for youre reply. No that was not what I was referring. Let me explain:

    The 5515evm works fine with the ADS1298 ECG module and using the 5515EVM's own uart connection(DB9).

    The connection between the 5515EVM and the CC2540(BLE) module however seems to have the Rx(5515EVM) connected to the Rx(CC2540) and the Tx(5515EVM) to the Tx(CC2540), which, of course means a signal collision.

    For this I checked the schematics of both the 5515EVM and the CC2540 module and found that this collision seems to be a fact and, thus a mistake.

    Before starting to 'patch' the pcb(5515EVM) I would like to have this checked, in order to know if I'm right.

    Schematics for 5515EVM:

    http://support.spectrumdigital.com/boards/evm5515/revb/

    Schematics for CC2540, in a .zip file:

    http://www.ti.com/tool/cc2540em-rd?keyMatch=CC2540EM&tisearch=Search-EN

    k.regards, Laurent

  • I opened the CC2540EM_discrete_schematic.pdf file inside the zip but can not see any UART connector nor UART signals.

  • Hello Steve,

    you should read SWRU19F. Chapter 17.1 describes the USART(UART & SPI) as were chapter 7.6 describes the possible location. In case of the CC2540EM(by TI) it was chosen to be UART0 on port P0.2(Rx), P0.3(Tx), P0.4, as you can see in table 7-1on page 81.

    In the mean time I have patched the TMS320C5515EVM and that made everything work fine. It is indeed a mistake in the schematics of this board and thus never tested by Spectrum Digital. So this matter is solved.

    But this brings up another compelling question. Am I the first to ever use these C5515EVM with a CC254xEM using the USART in UART mode?

    kind regards,

    Laurent

  • Hello Steve,

    little mistake. Its document SWRU191F.

    kind regards.,

    Laurent

  • "But this brings up another compelling question. Am I the first to ever use these C5515EVM with a CC254xEM using the USART in UART mode?"

    Maybe not. It is clearly documented that there is a hardware different that the receive and transmit lines must be crossed, so RX pin on each device is connected to TX on the other, that is RX-TX, TX-RX not wired RX-RX, TX-TX. The same applies to hardware flow control lines if you have implemented them.

    Regards.

  • Hello Steve,

    took a little time to verify and, as I already mentioned, swapping the Tx and Rx for the CC3540EM module works nice. I also checked the RTS/CTS connections and found that they are ok and need to remain as they are. I guess this problem is solved.

    thanks for your assistance.

    k.regards, Laurent