ESPHome 2025.5.0
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pn532_i2c.cpp
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1#include "pn532_i2c.h"
2#include "esphome/core/log.h"
3#include "esphome/core/hal.h"
4
5// Based on:
6// - https://cdn-shop.adafruit.com/datasheets/PN532C106_Application+Note_v1.2.pdf
7// - https://www.nxp.com/docs/en/nxp/application-notes/AN133910.pdf
8// - https://www.nxp.com/docs/en/nxp/application-notes/153710.pdf
9
10namespace esphome {
11namespace pn532_i2c {
12
13static const char *const TAG = "pn532_i2c";
14
16 uint8_t ready;
17 if (!this->read_bytes_raw(&ready, 1)) {
18 return false;
19 }
20 return ready == 0x01;
21}
22
23bool PN532I2C::write_data(const std::vector<uint8_t> &data) {
24 return this->write(data.data(), data.size()) == i2c::ERROR_OK;
25}
26
27bool PN532I2C::read_data(std::vector<uint8_t> &data, uint8_t len) {
28 delay(1);
29
30 if (this->read_ready_(true) != pn532::PN532ReadReady::READY) {
31 return false;
32 }
33
34 data.resize(len + 1);
35 this->read_bytes_raw(data.data(), len + 1);
36 return true;
37}
38
39bool PN532I2C::read_response(uint8_t command, std::vector<uint8_t> &data) {
40 ESP_LOGV(TAG, "Reading response");
41 uint8_t len = this->read_response_length_();
42 if (len == 0) {
43 return false;
44 }
45
46 ESP_LOGV(TAG, "Reading response of length %d", len);
47 if (!this->read_data(data, 6 + len + 2)) {
48 ESP_LOGD(TAG, "No response data");
49 return false;
50 }
51
52 if (data[1] != 0x00 && data[2] != 0x00 && data[3] != 0xFF) {
53 // invalid packet
54 ESP_LOGV(TAG, "read data invalid preamble!");
55 return false;
56 }
57
58 bool valid_header = (static_cast<uint8_t>(data[4] + data[5]) == 0 && // LCS, len + lcs = 0
59 data[6] == 0xD5 && // TFI - frame from PN532 to system controller
60 data[7] == command + 1); // Correct command response
61
62 if (!valid_header) {
63 ESP_LOGV(TAG, "read data invalid header!");
64 return false;
65 }
66
67 data.erase(data.begin(), data.begin() + 6); // Remove headers
68
69 uint8_t checksum = 0;
70 for (int i = 0; i < len + 1; i++) {
71 uint8_t dat = data[i];
72 checksum += dat;
73 }
74 checksum = ~checksum + 1;
75
76 if (data[len + 1] != checksum) {
77 ESP_LOGV(TAG, "read data invalid checksum! %02X != %02X", data[len], checksum);
78 return false;
79 }
80
81 if (data[len + 2] != 0x00) {
82 ESP_LOGV(TAG, "read data invalid postamble!");
83 return false;
84 }
85
86 data.erase(data.begin(), data.begin() + 2); // Remove TFI and command code
87 data.erase(data.end() - 2, data.end()); // Remove checksum and postamble
88
89 return true;
90}
91
93 std::vector<uint8_t> data;
94 if (!this->read_data(data, 6)) {
95 return 0;
96 }
97
98 if (data[1] != 0x00 && data[2] != 0x00 && data[3] != 0xFF) {
99 // invalid packet
100 ESP_LOGV(TAG, "read data invalid preamble!");
101 return 0;
102 }
103
104 bool valid_header = (static_cast<uint8_t>(data[4] + data[5]) == 0 && // LCS, len + lcs = 0
105 data[6] == 0xD5); // TFI - frame from PN532 to system controller
106
107 if (!valid_header) {
108 ESP_LOGV(TAG, "read data invalid header!");
109 return 0;
110 }
111
112 this->send_nack_();
113
114 // full length of message, including TFI
115 uint8_t full_len = data[4];
116 // length of data, excluding TFI
117 uint8_t len = full_len - 1;
118 if (full_len == 0)
119 len = 0;
120 return len;
121}
122
124 PN532::dump_config();
125 LOG_I2C_DEVICE(this);
126}
127
128} // namespace pn532_i2c
129} // namespace esphome
uint8_t checksum
Definition bl0906.h:3
ErrorCode write(const uint8_t *data, size_t len, bool stop=true)
writes an array of bytes to a device using an I2CBus
Definition i2c.h:190
optional< std::array< uint8_t, N > > read_bytes_raw()
Definition i2c.h:229
enum PN532ReadReady read_ready_(bool block)
Definition pn532.cpp:310
bool write_data(const std::vector< uint8_t > &data) override
Definition pn532_i2c.cpp:23
bool read_response(uint8_t command, std::vector< uint8_t > &data) override
Definition pn532_i2c.cpp:39
bool is_read_ready() override
Definition pn532_i2c.cpp:15
bool read_data(std::vector< uint8_t > &data, uint8_t len) override
Definition pn532_i2c.cpp:27
@ ERROR_OK
No error found during execution of method.
Definition i2c_bus.h:13
Providing packet encoding functions for exchanging data with a remote host.
Definition a01nyub.cpp:7
std::string size_t len
Definition helpers.h:301
void IRAM_ATTR HOT delay(uint32_t ms)
Definition core.cpp:28