diff --git a/configs/stm32f4discovery/README.txt b/configs/stm32f4discovery/README.txt index 3885d33063e..472621c1fec 100644 --- a/configs/stm32f4discovery/README.txt +++ b/configs/stm32f4discovery/README.txt @@ -31,6 +31,7 @@ Contents - PWM - UARTs - Timer Inputs/Outputs + - Quadrature Encoder - FPU - STM32F4DIS-BB - FSMC SRAM @@ -447,16 +448,52 @@ TIM14 free I/O pins. ** Port H pins are not supported by the MCU -Quadrature Encode Timer Inputs ------------------------------- +Quadrature Encoder: +=================== -If enabled (by setting CONFIG_QENCODER=y), then quadrature encoder will -use either TIM2 or TIM8 (see nsh/defconfig). If TIM2 is selected, the input -pins PA15 and PA1 for CH1 and CH2, respectively). If TIM8 is selected, then -PC6 and PI5 will be used for CH1 and CH2 (see include board.h for pin -definitions). + The nsh configuration has been used to test the Quadrture Encoder + (QEncoder, QE) with the following modifications to the configuration + file: -Selected via CONFIG_STM32F4DISCO_QETIMER + - These setting enable support for the common QEncode upper half driver: + + CONFIG_BOARD_INITIALIZE=y + + CONFIG_SENSORS=y + CONFIG_QENCODER=y + + - The timer 2 needs to be enabled: + + CONFIG_STM32_TIM2=y + + - This is a board setting that selected timer 2 for use with the + quadrature encode: + + CONFIG_STM32F4DISCO_QETIMER=2 + + - These settings enable the STM32 Quadrature encoder on timer 2: + + CONFIG_STM32_TIM2_QE=y + CONFIG_STM32_TIM4_QECLKOUT=2800000 + CONFIG_STM32_QENCODER_FILTER=y + CONFIG_STM32_QENCODER_SAMPLE_EVENT_6=y + CONFIG_STM32_QENCODER_SAMPLE_FDTS_4=y + + - These settings enable the test case at apps/examples/qencoder: + + CONFIG_EXAMPLES_QENCODER=y + CONFIG_EXAMPLES_QENCODER_DELAY=100 + CONFIG_EXAMPLES_QENCODER_DEVPATH="/dev/qe0" + + In this configuration, the QEncoder inputs will be on the TIM2 inputs of + PA15 and PA1 (CH1 and CH2 respectively). + + You can also use QEncoder with other timers, but keep in mind that only TIM2 + and TIM5 are 32bits timers, all other timers are 16-bit then the QE counter + will overflow after 65535. + + If TIM4 is selected, then PB6 and PB7 will be used for CH1 and CH2. + If TIM8 is selected, then PC6 and PI5 will be used for CH1 and CH2. FPU ===