From 8d1dee8929c428045d9b50a56169280771b4d4af Mon Sep 17 00:00:00 2001
From: Andre Thomas <andre1024@gmail.com>
Date: Sat, 5 Jan 2019 22:05:53 +0200
Subject: [PATCH] PN532: Enable 1ms ClockStretch

Enable 1ms clock stretch as per datasheet Table 12.25 (Timing for the I2C interface)
---
 sonoff/xsns_40_pn532_i2c.ino | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sonoff/xsns_40_pn532_i2c.ino b/sonoff/xsns_40_pn532_i2c.ino
index e41ba60ba..3c246a7d1 100644
--- a/sonoff/xsns_40_pn532_i2c.ino
+++ b/sonoff/xsns_40_pn532_i2c.ino
@@ -239,6 +239,8 @@ bool PN532_SAMConfig(void)
 void PN532_Detect(void)
 {
   if ((pn532_i2c_detected) || (pn532_i2c_disable)) { return; }
+  
+  Wire.setClockStretchLimit(1000); // Enable 1ms clock stretch as per datasheet Table 12.25 (Timing for the I2C interface)
 
   uint32_t ver = PN532_getFirmwareVersion();
   if (ver) {