diff options
| -rw-r--r-- | ports/nrf/modules/machine/uart.c | 61 |
1 files changed, 14 insertions, 47 deletions
diff --git a/ports/nrf/modules/machine/uart.c b/ports/nrf/modules/machine/uart.c index c3f8ea984..37c6c30a1 100644 --- a/ports/nrf/modules/machine/uart.c +++ b/ports/nrf/modules/machine/uart.c @@ -170,55 +170,22 @@ STATIC mp_obj_t machine_hard_uart_make_new(const mp_obj_type_t *type, size_t n_a config.interrupt_priority = 6; #endif - switch (args[ARG_baudrate].u_int) { - case 1200: - config.baudrate = NRF_UART_BAUDRATE_1200; - break; - case 2400: - config.baudrate = NRF_UART_BAUDRATE_2400; - break; - case 4800: - config.baudrate = NRF_UART_BAUDRATE_4800; - break; - case 9600: - config.baudrate = NRF_UART_BAUDRATE_9600; - break; - case 14400: - config.baudrate = NRF_UART_BAUDRATE_14400; - break; - case 19200: - config.baudrate = NRF_UART_BAUDRATE_19200; - break; - case 28800: - config.baudrate = NRF_UART_BAUDRATE_28800; - break; - case 38400: - config.baudrate = NRF_UART_BAUDRATE_38400; - break; - case 57600: - config.baudrate = NRF_UART_BAUDRATE_57600; - break; - case 76800: - config.baudrate = NRF_UART_BAUDRATE_76800; - break; - case 115200: - config.baudrate = NRF_UART_BAUDRATE_115200; - break; - case 230400: - config.baudrate = NRF_UART_BAUDRATE_230400; - break; - case 250000: - config.baudrate = NRF_UART_BAUDRATE_250000; - break; - case 1000000: - config.baudrate = NRF_UART_BAUDRATE_1000000; - break; - default: - nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, - "UART baudrate not supported, %u", args[ARG_baudrate].u_int)); - break; + // These baudrates are not supported, it seems. + if (args[ARG_baudrate].u_int < 1200 || args[ARG_baudrate].u_int > 1000000) { + mp_raise_ValueError("UART baudrate not supported"); } + // Magic: calculate 'baudrate' register from the input number. + // Every value listed in the datasheet will be converted to the + // correct register value, except for 192600. I believe the value + // listed in the nrf52 datasheet (0x0EBED000) is incorrectly rounded + // and should be 0x0EBEE000, as the nrf51 datasheet lists the + // nonrounded value 0x0EBEDFA4. + // Some background: + // https://devzone.nordicsemi.com/f/nordic-q-a/391/uart-baudrate-register-values/2046#2046 + config.baudrate = args[ARG_baudrate].u_int / 400 * (uint32_t)(400ULL * (uint64_t)UINT32_MAX / 16000000ULL); + config.baudrate = (config.baudrate + 0x800) & 0xffffff000; // rounding + config.pseltxd = MICROPY_HW_UART1_TX; config.pselrxd = MICROPY_HW_UART1_RX; |