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Diffstat (limited to 'docs/drivers/serial.md')
-rw-r--r-- | docs/drivers/serial.md | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/docs/drivers/serial.md b/docs/drivers/serial.md index dda75f629a..2c78f59043 100644 --- a/docs/drivers/serial.md +++ b/docs/drivers/serial.md @@ -33,7 +33,7 @@ On ARM platforms the bitbang driver causes connection issues when using it toget +-------+ +-------+ ``` -One GPIO pin is needed for the bitbang driver, as only one wire is used for receiving and transmitting data. This pin is referred to as the `SOFT_SERIAL_PIN` (SSP) in the configuration. A TRS or USB cable provides enough conductors for this driver to function. +One GPIO pin is needed for the bitbang driver, as only one wire is used for receiving and transmitting data. This pin is referred to as the `SOFT_SERIAL_PIN` (SSP) in the configuration. A TRS or USB cable provides enough conductors for this driver to function. ### Setup @@ -63,12 +63,12 @@ SERIAL_DRIVER = bitbang ## USART Half-duplex -Targeting ARM boards based on ChibiOS, where communication is offloaded to a USART hardware device that supports Half-duplex operation. The advantages over bitbanging are fast, accurate timings and reduced CPU usage. Therefore it is advised to choose Half-duplex over Bitbang if MCU is capable of utilising Half-duplex, and Full-duplex can't be used instead (e.g. lack of available GPIO pins, or imcompatible PCB design). +Targeting ARM boards based on ChibiOS, where communication is offloaded to a USART hardware device that supports Half-duplex operation. The advantages over bitbanging are fast, accurate timings and reduced CPU usage. Therefore it is advised to choose Half-duplex over Bitbang if MCU is capable of utilising Half-duplex, and Full-duplex can't be used instead (e.g. lack of available GPIO pins, or incompatible PCB design). ### Pin configuration ``` - LEFT RIGHT + LEFT RIGHT +-------+ | | +-------+ | | R R | | | | | SERIAL | | | @@ -80,7 +80,7 @@ Targeting ARM boards based on ChibiOS, where communication is offloaded to a USA +-------+ +-------+ ``` -Only one GPIO pin is needed for the Half-duplex driver, as only one wire is used for receiving and transmitting data. This pin is referred to as the `SERIAL_USART_TX_PIN` in the configuration. Ensure that the pin chosen for split communication can operate as the TX pin of the contoller's USART peripheral. A TRS or USB cable provides enough conductors for this driver to function. As the split connection is configured to operate in open-drain mode, an **external pull-up resistor is needed to keep the line high**. Resistor values of 1.5kΩ to 8.2kΩ are known to work. +Only one GPIO pin is needed for the Half-duplex driver, as only one wire is used for receiving and transmitting data. This pin is referred to as the `SERIAL_USART_TX_PIN` in the configuration. Ensure that the pin chosen for split communication can operate as the TX pin of the contoller's USART peripheral. A TRS or USB cable provides enough conductors for this driver to function. As the split connection is configured to operate in open-drain mode, an **external pull-up resistor is needed to keep the line high**. Resistor values of 1.5kΩ to 8.2kΩ are known to work. ::: warning ***Note:*** A pull-up resistor isn't required for RP2040 controllers configured with PIO subsystem. @@ -278,7 +278,7 @@ There are several advanced configuration options that can be defined in your key ### Baudrate -If you're having issues or need a higher baudrate with serial communication, you can change the baudrate which in turn controls the communication speed for serial. You want to lower the baudrate if you experience failed transactions. +If you're having issues or need a higher baudrate with serial communication, you can change the baudrate which in turn controls the communication speed for serial. You want to lower the baudrate if you experience failed transactions. ```c #define SELECT_SOFT_SERIAL_SPEED n @@ -307,19 +307,19 @@ This is the default time window in milliseconds in which a successful communicat ## Troubleshooting -If you're having issues withe serial communication, you can enable debug messages that will give you insights which part of the communication failed. The enable these messages add to your keyboards `config.h` file: +If you're having issues with serial communication, you can enable debug messages that will give you insights which part of the communication failed. The enable these messages add to your keyboards `config.h` file: ```c #define SERIAL_DEBUG ``` - + ::: tip The messages will be printed out to the `CONSOLE` output. For additional information, refer to [Debugging/Troubleshooting QMK](../faq_debug). ::: ## Alternate Functions for selected STM32 MCUs -Pins for USART Peripherals with +Pins for USART Peripherals with ### STM32F303 / Proton-C [Datasheet](https://www.st.com/resource/en/datasheet/stm32f303cc.pdf) |