From bab562dc3a511b2e357883bfee1b411bc3dac252 Mon Sep 17 00:00:00 2001
From: Adriaan Peeters <apeeters@lashout.net>
Date: Wed, 10 Jun 2020 04:23:25 +0200
Subject: [PATCH] Turn off PN532 RF field when not expecting a tag (#1046)

* Turn off PN532 RF field when not expecting a tag

Avoids interference with Wifi connectivity of nearby devices.

* Rename turn_off_rf_ method

* documented off command bytes

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>
---
 esphome/components/pn532/pn532.cpp | 18 +++++++++++++++++-
 esphome/components/pn532/pn532.h   |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/esphome/components/pn532/pn532.cpp b/esphome/components/pn532/pn532.cpp
index 93000a7421..792d92a6ac 100644
--- a/esphome/components/pn532/pn532.cpp
+++ b/esphome/components/pn532/pn532.cpp
@@ -86,6 +86,8 @@ void PN532::setup() {
     this->mark_failed();
     return;
   }
+
+  this->turn_off_rf_();
 }
 
 void PN532::update() {
@@ -114,13 +116,16 @@ void PN532::loop() {
 
   if (read.size() <= 2 || read[0] != 0x4B) {
     // Something failed
+    this->turn_off_rf_();
     return;
   }
 
   uint8_t num_targets = read[1];
-  if (num_targets != 1)
+  if (num_targets != 1) {
     // no tags found or too many
+    this->turn_off_rf_();
     return;
+  }
 
   // const uint8_t target_number = read[2];
   // const uint16_t sens_res = uint16_t(read[3] << 8) | read[4];
@@ -150,6 +155,17 @@ void PN532::loop() {
     format_uid(buf, nfcid, nfcid_length);
     ESP_LOGD(TAG, "Found new tag '%s'", buf);
   }
+
+  this->turn_off_rf_();
+}
+
+void PN532::turn_off_rf_() {
+  ESP_LOGVV(TAG, "Turning RF field OFF");
+  this->pn532_write_command_check_ack_({
+      0x32,  // RFConfiguration
+      0x1,   // RF Field
+      0x0    // Off
+  });
 }
 
 float PN532::get_setup_priority() const { return setup_priority::DATA; }
diff --git a/esphome/components/pn532/pn532.h b/esphome/components/pn532/pn532.h
index 49d5878265..3a734b7ba2 100644
--- a/esphome/components/pn532/pn532.h
+++ b/esphome/components/pn532/pn532.h
@@ -55,6 +55,8 @@ class PN532 : public PollingComponent,
 
   bool read_ack_();
 
+  void turn_off_rf_();
+
   bool requested_read_{false};
   std::vector<PN532BinarySensor *> binary_sensors_;
   std::vector<PN532Trigger *> triggers_;