esphome/esphome/components/pn532_i2c/pn532_i2c.cpp
2021-09-22 20:07:43 +02:00

132 lines
3.4 KiB
C++

#include "pn532_i2c.h"
#include "esphome/core/log.h"
#include "esphome/core/hal.h"
// Based on:
// - https://cdn-shop.adafruit.com/datasheets/PN532C106_Application+Note_v1.2.pdf
// - https://www.nxp.com/docs/en/nxp/application-notes/AN133910.pdf
// - https://www.nxp.com/docs/en/nxp/application-notes/153710.pdf
namespace esphome {
namespace pn532_i2c {
static const char *const TAG = "pn532_i2c";
bool PN532I2C::write_data(const std::vector<uint8_t> &data) {
return this->write(data.data(), data.size()) == i2c::ERROR_OK;
}
bool PN532I2C::read_data(std::vector<uint8_t> &data, uint8_t len) {
delay(1);
std::vector<uint8_t> ready;
ready.resize(1);
uint32_t start_time = millis();
while (true) {
if (this->read_bytes_raw(ready.data(), 1)) {
if (ready[0] == 0x01)
break;
}
if (millis() - start_time > 100) {
ESP_LOGV(TAG, "Timed out waiting for readiness from PN532!");
return false;
}
}
data.resize(len + 1);
this->read_bytes_raw(data.data(), len + 1);
return true;
}
bool PN532I2C::read_response(uint8_t command, std::vector<uint8_t> &data) {
ESP_LOGV(TAG, "Reading response");
uint8_t len = this->read_response_length_();
if (len == 0) {
return false;
}
ESP_LOGV(TAG, "Reading response of length %d", len);
if (!this->read_data(data, 6 + len + 2)) {
ESP_LOGD(TAG, "No response data");
return false;
}
if (data[1] != 0x00 && data[2] != 0x00 && data[3] != 0xFF) {
// invalid packet
ESP_LOGV(TAG, "read data invalid preamble!");
return false;
}
bool valid_header = (static_cast<uint8_t>(data[4] + data[5]) == 0 && // LCS, len + lcs = 0
data[6] == 0xD5 && // TFI - frame from PN532 to system controller
data[7] == command + 1); // Correct command response
if (!valid_header) {
ESP_LOGV(TAG, "read data invalid header!");
return false;
}
data.erase(data.begin(), data.begin() + 6); // Remove headers
uint8_t checksum = 0;
for (int i = 0; i < len + 1; i++) {
uint8_t dat = data[i];
checksum += dat;
}
checksum = ~checksum + 1;
if (data[len + 1] != checksum) {
ESP_LOGV(TAG, "read data invalid checksum! %02X != %02X", data[len], checksum);
return false;
}
if (data[len + 2] != 0x00) {
ESP_LOGV(TAG, "read data invalid postamble!");
return false;
}
data.erase(data.begin(), data.begin() + 2); // Remove TFI and command code
data.erase(data.end() - 2, data.end()); // Remove checksum and postamble
return true;
}
uint8_t PN532I2C::read_response_length_() {
std::vector<uint8_t> data;
if (!this->read_data(data, 6)) {
return 0;
}
if (data[1] != 0x00 && data[2] != 0x00 && data[3] != 0xFF) {
// invalid packet
ESP_LOGV(TAG, "read data invalid preamble!");
return 0;
}
bool valid_header = (static_cast<uint8_t>(data[4] + data[5]) == 0 && // LCS, len + lcs = 0
data[6] == 0xD5); // TFI - frame from PN532 to system controller
if (!valid_header) {
ESP_LOGV(TAG, "read data invalid header!");
return 0;
}
this->send_nack_();
// full length of message, including TFI
uint8_t full_len = data[4];
// length of data, excluding TFI
uint8_t len = full_len - 1;
if (full_len == 0)
len = 0;
return len;
}
void PN532I2C::dump_config() {
PN532::dump_config();
LOG_I2C_DEVICE(this);
}
} // namespace pn532_i2c
} // namespace esphome