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22 changes: 6 additions & 16 deletions ports/espressif/common-hal/pulseio/PulseIn.c
Original file line number Diff line number Diff line change
Expand Up @@ -80,9 +80,8 @@ void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t *self, const mcu
}
// We add one to the maxlen version to ensure that two symbols at lease are
// captured because we may skip the first portion of a symbol.
self->raw_symbols_size = (maxlen / 2 + 1) * sizeof(rmt_symbol_word_t);
// RMT DMA mode cannot access PSRAM -> ensure raw_symbols is in internal ram
self->raw_symbols = (rmt_symbol_word_t *)port_malloc(self->raw_symbols_size, true);
self->raw_symbols_size = MIN(64, maxlen / 2 + 1) * sizeof(rmt_symbol_word_t);
self->raw_symbols = (rmt_symbol_word_t *)m_malloc_without_collect(self->raw_symbols_size);
if (self->raw_symbols == NULL) {
m_free(self->buffer);
m_malloc_fail(self->raw_symbols_size);
Expand Down Expand Up @@ -110,26 +109,17 @@ void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t *self, const mcu
.clk_src = RMT_CLK_SRC_DEFAULT,
// 2 us resolution so we can capture 65ms pulses. The RMT period is only 15 bits.
.resolution_hz = 1000000 / 2,
.mem_block_symbols = self->raw_symbols_size,
.flags.with_dma = 1
.mem_block_symbols = SOC_RMT_MEM_WORDS_PER_CHANNEL,
};
// If we fail here, the self->buffer will be garbage collected.
esp_err_t result = rmt_new_rx_channel(&config, &self->channel);
if (result != ESP_OK) {
port_free(self->raw_symbols);
raise_esp_error(result);
}
// If we fail here, the buffers allocated above will be garbage collected.
CHECK_ESP_RESULT(rmt_new_rx_channel(&config, &self->channel));

rmt_rx_event_callbacks_t rx_callback = {
.on_recv_done = _done_callback
};
rmt_rx_register_event_callbacks(self->channel, &rx_callback, self);
rmt_enable(self->channel);
result = rmt_receive(self->channel, self->raw_symbols, self->raw_symbols_size, &rx_config);
if (result != ESP_OK) {
port_free(self->raw_symbols);
raise_esp_error(result);
}
rmt_receive(self->channel, self->raw_symbols, self->raw_symbols_size, &rx_config);
}

bool common_hal_pulseio_pulsein_deinited(pulseio_pulsein_obj_t *self) {
Expand Down