CC2640R2F: I2C operates well while connected to the debugger but now while powered externally

PATRICK OHARA

Part Number: CC2640R2F
Other Parts Discussed in Thread: OPT3002

Hello,

I have a USB to UART w/ battery charger powering my CC2640r2 and peripheral four OPT3002 devices. When I'm connected to the debugger (via LaunchPad), I can compile, download and run the application. I can send commands via the USB port and collect optical readings from the OPT3002 - no problem. When I disconnect the debugger and power the device from the USB (or battery) the I2C bus no longer responds. I've checked the obvious stuff - supply voltages, gnd, etc. Is there something that the debugger is doing with respect to the I2C bus, Rx/Tx lines, or something else that would not happen if it were not connected and running in debug mode?

Any thoughts would be appreciated.

Patrick

over 5 years ago

0 PATRICK OHARA over 5 years ago

Genius 3205 points

Hello,

It turns out that I had enabled Flow Control by assigning pins to RTS & CTS but I never hooked them up. Therefore Flow Control was enabled but not implemented in the hardware. As a result, the CC2640r2 would issue a write via Tx, but it never got a response via Rx. If you intend not to use Flow Control, be sure to do the following in your board file.

// UART Board
#define Board_UART_RX                       IOID_1
#define Board_UART_TX                       IOID_0
#define Board_UART_CTS                      PIN_UNASSIGNED //IOID_5
#define Board_UART_RTS                      PIN_UNASSIGNED //IOID_6

Thanks,

Patrick

0 Ryan Brown1 over 5 years ago

TI__Guru**** 223737 points

Hello Patrick,

Thank you for providing the solution to your issue!

Regards,
Ryan

Bluetooth®︎

Bluetooth forum

CC2640R2F: I2C operates well while connected to the debugger but now while powered externally