From 5e1bfa281b0985a0e38d552bde4ccb810e510ffa Mon Sep 17 00:00:00 2001 From: rusefi Date: Sun, 9 Dec 2018 14:47:24 -0500 Subject: [PATCH] docs --- firmware/hw_layer/digital_input_hw.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/firmware/hw_layer/digital_input_hw.cpp b/firmware/hw_layer/digital_input_hw.cpp index 4dccc9781b..483cffe481 100644 --- a/firmware/hw_layer/digital_input_hw.cpp +++ b/firmware/hw_layer/digital_input_hw.cpp @@ -2,6 +2,21 @@ * @file digital_input_hw.cpp * @brief Helper methods related to Input Capture Unit (ICU) * + * There are some ChibiOS limitation or STM32 limitations or limitations of my brain + * + * See http://www.chibios.com/forum/viewtopic.php?t=1461 + * "PWM input requires a whole timer on the STM32. + * You could use channel 1 and channel 2 of the same timer but not simultaneously. + * Giovanni" + * + * See http://www.chibios.com/forum/viewtopic.php?f=2&t=247&hilit=icu+channel&start=50 + * "It is not possible, the TIM timers support one ICU channel at time. + * Giovanni" + * + * See https://stackoverflow.com/questions/43440599/stm32-multi-channel-input-capture-overcapturing-on-all-channels-interrupts-not + * where they seem to be capturing something on multiple channels maybe not PWM mode of ICU is the key difference? + * + * * @date Jun 23, 2013 * @author Andrey Belomutskiy, (c) 2012-2018 */