CC2538 RF overlapping PIN usage

[AnonMall]

Description

In the CC2538 RF initialization (cc2538_init() in cpu/cc2538/radio/cc2538_rf.c) the function uses some of the pins in order to observe the state of signals. For this it differentiates between the openmote-cc2538 and the cc2538dk board, but when used with a REMote-RevB for example, the pins interfere with the other pins needed for I²C.
Therefore using a REMote-RevB as a I²C Bus master additionally to the CC2538 radio transceiver causes problems.

Steps to reproduce the issue

Use a REMote-RevB as a I²C bus master while also adding the cc2538_rf module.

Expected results

Bus communication and 2.4 GHz communication functions without problem.

Actual results

I²C Bus communication fails and the CC2538 I²C code is not able to able to recover:
recover_i2c_bus(): Failed to release SDA after 200 SCL pulses

Versions

Solution

A solution was to was to add an other ifdef capsulation and differentiating between more boards. The code snippet in question is starting at line 99 in the mentioned file and is as follows:

/* Select output pins for the three observable signals */
#ifdef BOARD_OPENMOTE_CC2538
    CCTEST_OBSSEL0 = 0;                        /* PC0 = USB_SEL        */
    CCTEST_OBSSEL1 = 0;                        /* PC1 = N/C            */
    CCTEST_OBSSEL2 = 0;                        /* PC2 = N/C            */
    CCTEST_OBSSEL3 = 0;                        /* PC3 = USER_BUTTON    */
    CCTEST_OBSSEL4 = OBSSEL_EN | rfc_obs_sig0; /* PC4 = RED_LED        */
    CCTEST_OBSSEL5 = 0;                        /* PC5 = ORANGE_LED     */
    CCTEST_OBSSEL6 = OBSSEL_EN | rfc_obs_sig1; /* PC6 = YELLOW_LED     */
    CCTEST_OBSSEL7 = OBSSEL_EN | rfc_obs_sig2; /* PC7 = GREEN_LED      */
#else
    /* Assume BOARD_CC2538DK (or similar). */
    CCTEST_OBSSEL0 = OBSSEL_EN | rfc_obs_sig0; /* PC0 = LED_1 (red)    */
    CCTEST_OBSSEL1 = OBSSEL_EN | rfc_obs_sig1; /* PC1 = LED_2 (yellow) */
    CCTEST_OBSSEL2 = OBSSEL_EN | rfc_obs_sig2; /* PC2 = LED_3 (green)  */
    CCTEST_OBSSEL3 = 0;                        /* PC3 = LED_4 (red)    */
    CCTEST_OBSSEL4 = 0;                        /* PC4 = BTN_L          */
    CCTEST_OBSSEL5 = 0;                        /* PC5 = BTN_R          */
    CCTEST_OBSSEL6 = 0;                        /* PC6 = BTN_UP         */
    CCTEST_OBSSEL7 = 0;                       /* PC7 = BTN_DN         */
#endif

I would propose either to generalize it and offer the pins via the board configuration or to add more ifdef capsulations for other boards.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you want me to ignore this issue, please mark it with the "State: don't stale" label. Thank you for your contributions.

[maribu]

The driver allows now to configure the observable signals since e2c57cd