From 91b9f7cae8e1a1de04e8a2a9246bb36dd9e4c5dc Mon Sep 17 00:00:00 2001
From: Christopher Pepper <p3p@p3psoft.co.uk>
Date: Mon, 11 Nov 2019 00:56:56 +0000
Subject: [PATCH] adc lowpass first reading initialisation

---
 package.json         | 2 +-
 system/lpc176x/adc.h | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 9ab4389..5b2b724 100755
--- a/package.json
+++ b/package.json
@@ -2,5 +2,5 @@
     "name": "framework-arduino-lpc176x",
     "description": "Arduino Wiring-based Framework (LPC176x CMSIS 5)",
     "url": "https://www.arduino.cc/en/Main/Software",
-    "version": "0.2.1"
+    "version": "0.2.2"
 }
diff --git a/system/lpc176x/adc.h b/system/lpc176x/adc.h
index f7cee54..4393789 100644
--- a/system/lpc176x/adc.h
+++ b/system/lpc176x/adc.h
@@ -298,9 +298,9 @@ struct ADC {
   };
 
   struct LowpassFilter {
-    uint32_t data_delay = 0x7FFF << ADC_LOWPASS_K_VALUE;
+    uint32_t data_delay = 0xFFFFFFFF;
     [[gnu::always_inline]] inline uint16_t update(uint16_t value) {
-      data_delay = data_delay - (data_delay >> ADC_LOWPASS_K_VALUE) + value;
+      data_delay = data_delay == 0xFFFFFFFF ? value << ADC_LOWPASS_K_VALUE : data_delay - (data_delay >> ADC_LOWPASS_K_VALUE) + value;
       return (uint16_t)(data_delay >> ADC_LOWPASS_K_VALUE);
     }
   };