Ashin Walpola
0e9525162d
obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but that tree was gitignored, so a clone of this repository could not build the firmware it ships. It is now committed here as ordinary files in its own folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP bridge's signature verification (--trust) used on the bench. Nothing is fetched from or pushed to the colleague's repository; this repository and its remotes carry everything. The folder's own .gitignore keeps build output, downloaded components and private key material out, as it did there; the committed file set is identical to that repository's tracked files. The ESP32-C5 is still flashed from obu-firmware/, which only takes vanetza-idf from microbu-esp32c5/, so the two stay separate folders. FLASHING.md says how to take a newer version of the colleague's tree (copy it over the folder, rebuild, test, commit).
34 lines
950 B
C++
34 lines
950 B
C++
#include "transmission.hpp"
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#include <chrono>
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namespace vanetza
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{
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namespace dcc
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{
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Clock::duration Transmission::channel_occupancy() const
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{
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using namespace std::chrono;
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// assume 6 Mbps as default data rate
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const access::DataRateG5* rate = data_rate() ? data_rate() : &access::G5_6Mbps;
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// PHY
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static const auto phy_preamble = microseconds(32);
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static const auto phy_signal = microseconds(8);
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// MAC
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static const std::size_t bytes_epd = 2; // EtherType Protocol Discrimination (no LLC!)
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static const std::size_t bytes_mac = 34; // 802.11 MAC header
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const std::size_t bytes = rate->data_length(body_length() + bytes_epd + bytes_mac);
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const double seconds_per_byte = 1.0 / (rate->bytes_per_second());
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const duration<double> data_duration { bytes * seconds_per_byte };
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return phy_preamble + phy_signal + duration_cast<microseconds>(data_duration);
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}
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} // namespace dcc
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} // namespace vanetza
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