1 files changed, 40 insertions, 0 deletions
diff --git a/arduino/libraries/Bluefruit52Lib/examples/Hardware/nfc_to_gpio/nfc_to_gpio.ino b/arduino/libraries/Bluefruit52Lib/examples/Hardware/nfc_to_gpio/nfc_to_gpio.ino
new file mode 100755
index 0000000..89fa7cb
--- /dev/null
+++ b/arduino/libraries/Bluefruit52Lib/examples/Hardware/nfc_to_gpio/nfc_to_gpio.ino
@@ -0,0 +1,40 @@
+// This sketch will check if the NFC pins are configured for NFC mode,
+// and if so it will switch them to operate in GPIO mode. A system
+// reset is required before this change takes effect since the CONFIG
+// memory is only read on power up.
+
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !!!!! IMPORTANT NOTE ... READ BEFORE RUNNING THIS SKETCH !!!!!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+// UICR customer registers are meant to be stored with values
+// that are supposed to stay there during the life time of the softdevice.
+// You cannot erase them without erasing everything on chip, so setting the
+// NFC pins to GPIO mode is a ONE WAY OPERATION and you will need a debugger
+// like a Segger J-Link to set them back to NFC mode!
+
+void setup() {
+  Serial.begin(115200);
+  while ( !Serial ) delay(10);   // for nrf52840 with native usb
+  
+  Serial.println("Bluefruit52 NFC to GPIO Pin Config");
+  Serial.println("----------------------------------\n");
+      if ((NRF_UICR->NFCPINS & UICR_NFCPINS_PROTECT_Msk) == (UICR_NFCPINS_PROTECT_NFC << UICR_NFCPINS_PROTECT_Pos)){
+        Serial.println("Fix NFC pins");
+        NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;
+        while (NRF_NVMC->READY == NVMC_READY_READY_Busy);
+        NRF_UICR->NFCPINS &= ~UICR_NFCPINS_PROTECT_Msk;
+        while (NRF_NVMC->READY == NVMC_READY_READY_Busy);
+        NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
+        while (NRF_NVMC->READY == NVMC_READY_READY_Busy);
+        Serial.println("Done");
+        delay(500);
+        NVIC_SystemReset();
+      }
+
+}
+void loop() {
+  // put your main code here, to run repeatedly:
+}