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Bitbang i2c: switch scl to input for reading

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This commit is contained in:
Michael Himing 2022-02-02 22:54:35 +11:00
parent 2964e966b1
commit 5472f41860
1 changed files with 2 additions and 0 deletions
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2
shared-module/bitbangio/I2C.c
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@ -49,9 +49,11 @@ STATIC void scl_release(bitbangio_i2c_obj_t *self) {
uint32_t count = self->us_timeout;
delay(self);
// For clock stretching, wait for the SCL pin to be released, with timeout.
common_hal_digitalio_digitalinout_switch_to_input(&self->scl, PULL_UP);
for (; !common_hal_digitalio_digitalinout_get_value(&self->scl) && count; --count) {
common_hal_mcu_delay_us(1);
}
common_hal_digitalio_digitalinout_switch_to_output(&self->scl, true, DRIVE_MODE_OPEN_DRAIN);
// raise exception on timeout
if (count == 0) {
mp_raise_msg(&mp_type_TimeoutError, translate("Clock stretch too long"));