kopia lustrzana https://github.com/RPiks/pico-WSPR-tx
98 wiersze
3.4 KiB
C
98 wiersze
3.4 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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// Roman Piksaykin [piksaykin@gmail.com], R2BDY
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// https://www.qrz.com/db/r2bdy
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//
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///////////////////////////////////////////////////////////////////////////////
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//
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//
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// TxChannel.c - Produces a time-accurate `bit` stream.
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// Invokes a `modulator` function.
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// DESCRIPTION
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// Receives data asynchronously. Calls low level modulator function
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// synchronously according to params.
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//
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// HOWTOSTART
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// -
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//
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// PLATFORM
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// Raspberry Pi pico.
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//
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// REVISION HISTORY
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// -
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//
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// PROJECT PAGE
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// https://github.com/RPiks/pico-WSPR-tx
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//
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// LICENCE
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// MIT License (http://www.opensource.org/licenses/mit-license.php)
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//
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// Copyright (c) 2023 by Roman Piksaykin
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//
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// Permission is hereby granted, free of charge,to any person obtaining a copy
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// of this software and associated documentation files (the Software), to deal
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// in the Software without restriction,including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY,WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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///////////////////////////////////////////////////////////////////////////////
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#include "TxChannel.h"
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TxChannelContext *pTX = NULL;
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void __not_in_flash_func (TxChannelISR)(void)
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{
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if(!pTX)
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{
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pTX->_tm_future_call += 500LL;
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goto EXIT;
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}
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pTX->_pf_modulator(FREQ_STEP_MILLIHERTZ, pTX->_u8byte_buffer[pTX->_ix_output++]);
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pTX->_tm_future_call += pTX->_bit_period_us;
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EXIT:
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hw_clear_bits(&timer_hw->intr, 1U<<pTX->_timer_alarm_num);
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timer_hw->alarm[pTX->_timer_alarm_num] = (uint32_t)pTX->_tm_future_call;
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}
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/// @brief Initializes a TxChannel context. Starts ISR.
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/// @param bit_period_us Period of data bits, BPS speed = 1e6/bit_period_us.
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/// @param timer_alarm_num Pico-specific hardware timer resource id.
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/// @param pfmodulator Ptr to low level real-time modulator function.
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/// @return the Context.
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TxChannelContext *TxChannelInit(const uint32_t bit_period_us, uint8_t timer_alarm_num,
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void *pfmodulator)
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{
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assert_(pfmodulator);
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assert_(bit_period_us > 10);
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TxChannelContext *p = calloc(1, sizeof(TxChannelContext));
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assert_(p);
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p->_bit_period_us = bit_period_us;
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p->_timer_alarm_num = timer_alarm_num;
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p->_pf_modulator = pfmodulator;
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hw_set_bits(&timer_hw->inte, 1U << p->_timer_alarm_num);
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irq_set_exclusive_handler(TIMER_IRQ_0, TxChannelISR);
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irq_set_priority(TIMER_IRQ_0, 0x00);
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irq_set_enabled(TIMER_IRQ_0, true);
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p->_tm_future_call = timer_hw->timerawl + 500LL;
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timer_hw->alarm[p->_timer_alarm_num] = (uint32_t)p->_tm_future_call;
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return p;
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}
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