IWR1642BOOST: Using RS232 TX and RX pins for data transfer

Herman Stubeda

Part Number: IWR1642BOOST

Hello,

I would like to use the RS232 pins to send data to an Arduino. These pins are numbered 5 and 7 (for Tx and Rx, respectively) on the J6 header on the EVM board. These pins are also named N5 and N4, respectively, in the data sheet. The arduino has a library using which I can configure the serial. But in the mmWave SDK, I could not find any references to RS232. So I assumed that the UART driver may be what I was looking for. I also noticed that in the mmWave demo, UART A was configured to pins N5 and N4:

    Pinmux_Set_OverrideCtrl(SOC_XWR16XX_PINN5_PADBE, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL);    
    Pinmux_Set_FuncSel(SOC_XWR16XX_PINN5_PADBE, SOC_XWR16XX_PINN5_PADBE_MSS_UARTA_TX);
    Pinmux_Set_OverrideCtrl(SOC_XWR16XX_PINN4_PADBD, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL);    
    Pinmux_Set_FuncSel(SOC_XWR16XX_PINN4_PADBD, SOC_XWR16XX_PINN4_PADBD_MSS_UARTA_RX);

I then hoped to connect Arduino TX and RX lines to pins 5 and 7 on J6 of EVM at baud rate 115200 and 8N1 configuration to control the sensor. I tried sending the "sensorStop\r\n" command; however this did not work.

Is there anything I'm missing?

Thanks.

over 7 years ago

0 Herman Stubeda over 7 years ago

Intellectual 290 points

Also. serial communication on Arduino pins TX/RX uses TTL logic levels (5V or 3.3V depending on the board). Do the RS232 pins on the IWR1642BOOST EVM use TTL as well? If yes, does the 5 vs 3.3 V level matter? Thanks.

0 Radio-Joe over 7 years ago in reply to Herman Stubeda

TI__Mastermind 37500 points

Hello,
The AR_RS232TX, and AR_RS232RX are 3.3v signals. 5v IO to the Radar Sensor is not recommended.

The default serial port connections are from the Radar Sensor, to the XDS110. You need to check that you have
changed the resistors. You could enable the J6-5 first, and send data from the Test PC using the Visualizer, you should get data
back to the Test PC and to the Arduino.

The serial port data is defined at the Radar Sensor end.
sheet 3, RS232TX U2-N5 -> AR_RS232TX
sheet 11, AR_RS232TX -> R169 (DNI) -> J6-5
sheet 12, AR_RS232TX -> R21 (DNI) -> J1-57
sheet 14, AR_RS232TX -> R128 U6-33 (XDS110)

You need to change the resistors, for AR_RX232TX, remove R128, 0 ohm, install a 0 ohm resistor in R169

sheet 14, U6-34(XDS110) -> R129 -> AR_RS232RX
sheet 12, J1-55 -> R33 (DNI) -> AR_RS232RX
sheet 11, J6-7 -> R166(DNI) -> AR_RS232RX
sheet 3, AR_RS232RX -> U2-N4 RS232_RX

You need to change the resistors, for AR_RS232RX, remove R129, 0 ohm, install a 0 ohm resistor at R166

Regards,
Joe Quintal

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IWR1642BOOST: Using RS232 TX and RX pins for data transfer