djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Check for no pullups on I2C on nrf; give arduino nano 33 ble two I2C devices

Browse Source
This commit is contained in:
Dan Halbert 2019-11-02 22:47:03 -04:00
parent 43b8d5e8ab
commit 85a648224f
3 changed files with 32 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
ports/atmel-samd/common-hal/busio/I2C.c
View File

@ -116,6 +116,7 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
if (i2c_m_sync_set_baudrate(&self->i2c_desc, 0, frequency / 1000) != ERR_NONE) {
reset_pin_number(sda->number);
reset_pin_number(scl->number);
common_hal_busio_i2c_deinit(self);
mp_raise_ValueError(translate("Unsupported baudrate"));
}

7
ports/nrf/boards/arduino_nano_33_ble/mpconfigboard.mk
View File

@ -22,3 +22,10 @@ endif
NRF_DEFINES += -DNRF52840_XXAA -DNRF52840
INTERNAL_FLASH_FILESYSTEM = 1
# Allocate two, not just one I2C peripheral, so that we have both
# on-board and off-board I2C available.
# When SPIM3 becomes available we'll be able to have two I2C and two SPI peripherals.
# We use a CFLAGS define here because there are include order issues
# if we try to include "mpconfigport.h" into nrfx_config.h .
CFLAGS += -DCIRCUITPY_NRF_NUM_I2C=2

29
ports/nrf/common-hal/busio/I2C.c
View File

@ -28,13 +28,12 @@
*/
#include "shared-bindings/busio/I2C.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "supervisor/shared/translate.h"
#include "nrfx_twim.h"
#include "nrf_gpio.h"
#include "nrfx_spim.h"
#include "nrf_gpio.h"
@ -107,7 +106,7 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *
for (size_t i = 0 ; i < MP_ARRAY_SIZE(twim_peripherals); i++) {
if (!twim_peripherals[i].in_use) {
self->twim_peripheral = &twim_peripherals[i];
self->twim_peripheral->in_use = true;
// Mark it as in_use later after other validation is finished.
break;
}
}
@ -116,10 +115,27 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *
mp_raise_ValueError(translate("All I2C peripherals are in use"));
}
// Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
nrf_gpio_cfg_input(scl->number, NRF_GPIO_PIN_PULLDOWN);
nrf_gpio_cfg_input(sda->number, NRF_GPIO_PIN_PULLDOWN);
common_hal_mcu_delay_us(10);
nrf_gpio_cfg_input(scl->number, NRF_GPIO_PIN_NOPULL);
nrf_gpio_cfg_input(sda->number, NRF_GPIO_PIN_NOPULL);
// We must pull up within 3us to achieve 400khz.
common_hal_mcu_delay_us(3);
if (!nrf_gpio_pin_read(sda->number) || !nrf_gpio_pin_read(scl->number)) {
reset_pin_number(sda->number);
reset_pin_number(scl->number);
mp_raise_RuntimeError(translate("SDA or SCL needs a pull up"));
}
nrfx_twim_config_t config = NRFX_TWIM_DEFAULT_CONFIG;
config.scl = scl->number;
config.sda = sda->number;
// change freq. only if it's less than the default 400K
if (frequency < 100000) {
config.frequency = NRF_TWIM_FREQ_100K;
@ -132,6 +148,8 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *
claim_pin(sda);
claim_pin(scl);
// About to init. If we fail after this point, common_hal_busio_i2c_deinit() will set in_use to false.
self->twim_peripheral->in_use = true;
nrfx_err_t err = nrfx_twim_init(&self->twim_peripheral->twim, &config, NULL, NULL);
// A soft reset doesn't uninit the driver so we might end up with a invalid state
@ -152,8 +170,9 @@ bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
}
void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self))
if (common_hal_busio_i2c_deinited(self)) {
return;
}
nrfx_twim_uninit(&self->twim_peripheral->twim);