ESP32 无法检测到 PN532 NFC 模块
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【中文标题】ESP32 无法检测到 PN532 NFC 模块【英文标题】:ESP32 failing to detect PN532 NFC module 【发布时间】:2018-09-12 01:52:16 【问题描述】:过去几天我一直在努力让 Elechouse PN532 V3 模块通过 I2C 与 ESP32 一起工作。 PN532 模块本身可以很好地与 Raspberry Pi 配合使用。
这是电路(实际上并未使用 SparkFun ESP32 板,仅供参考)
这是我要运行的代码
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <NfcAdapter.h>
PN532_I2C pn532i2c(Wire);
PN532 nfc(pn532i2c);
void setup(void)
Serial.begin(115200);
Serial.println("Hello!");
Wire.begin(18, 19);
nfc.begin();
uint32_t versiondata = nfc.getFirmwareVersion();
if (! versiondata)
Serial.print("Didn't find PN53x board");
while (1); // halt
// Got ok data, print it out!
Serial.print("Found chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX);
Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC);
Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
// Set the max number of retry attempts to read from a card
// This prevents us from waiting forever for a card, which is
// the default behaviour of the PN532.
nfc.setPassiveActivationRetries(0xFF);
// configure board to read RFID tags
nfc.SAMConfig();
Serial.println("Waiting for an ISO14443A card");
void loop(void)
boolean success;
uint8_t uid[] = 0, 0, 0, 0, 0, 0, 0 ; // Buffer to store the returned UID
uint8_t uidLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &uid[0], &uidLength);
if (success)
Serial.println("Found a card!");
Serial.print("UID Length: ");Serial.print(uidLength, DEC);Serial.println(" bytes");
Serial.print("UID Value: ");
for (uint8_t i=0; i < uidLength; i++)
Serial.print(" 0x");Serial.print(uid[i], HEX);
Serial.println("");
// Wait 1 second before continuing
delay(1000);
else
// PN532 probably timed out waiting for a card
Serial.println("Timed out waiting for a card");
最后是串行输出:Didn't find PN53X board
任何想法我做错了什么?
编辑:我使用 https://github.com/elechouse/PN532 的库和 ESP32 开发板是 Wemos Lolin32 Lite 克隆。
【问题讨论】:
嘿,你能找出原因吗,因为我遇到了同样的问题?而且esp32没有内部引体向上吗? 【参考方案1】:我没有任何硬件来验证这一点,但来自 'PN532-PN532_HSU\NDEF\README.md'
For the Adafruit Shield using I2C
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <NfcAdapter.h>
PN532_I2C pn532_i2c(Wire);
NfcAdapter nfc = NfcAdapter(pn532_i2c);
尝试在您的代码中使用上述内容?我还建议您更深入地查看 PN532 I2C 示例。 PN532 I2C 库代码定义了一个“唤醒”功能:
void PN532_I2C::wakeup()
delay(500); // wait for all ready to manipulate pn532
该评论让我相信该设备在准备好通话之前可能需要很长的延迟(500 毫秒)。
祝你好运。
【讨论】:
【参考方案2】:sda 和 scl 分别是 21 和 22 还要确保将模式更改为 I2C(PN532 模块上的那些跳线): doc - page 3
【讨论】:
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