Augment pw_dumb_io_baremetal_stm32f429 docs
* Disambiguate TX/RX direction for UART sample.
* Add more details about terminals.
* Fix a typo in a paragraph.
Change-Id: I14ddc4f1bf5a0c1b7f96114232418a84e4379aa7
diff --git a/pw_dumb_io_baremetal_stm32f429/docs.rst b/pw_dumb_io_baremetal_stm32f429/docs.rst
index 423f69e..b47b88c 100644
--- a/pw_dumb_io_baremetal_stm32f429/docs.rst
+++ b/pw_dumb_io_baremetal_stm32f429/docs.rst
@@ -38,12 +38,26 @@
Module usage
============
-After building a an executable that utilizes this backend, flash the
+After building an executable that utilizes this backend, flash the
produced .elf binary to the development board. Then, using a serial
-communication terminal (like minicom or screen), connect to the device at a
-baud rate of 115200 (8N1). If you're not using a STM32F429I-DISC1 development
-board, manually connect a USB TLL adapter to pins `A9` (TX) and
-`A10` (RX).
+communication terminal like minicom/screen (Linux/Mac) or TeraTerm (Windows),
+connect to the device at a baud rate of 115200 (8N1). If you're not using a
+STM32F429I-DISC1 development board, manually connect a USB-to-serial TTL adapter
+to pins ``PA9`` (MCU TX) and ``PA10`` (MCU RX), making sure to match logic
+levels (e.g. 3.3V versus 1.8V).
+
+Sample connection diagram
+-------------------------
+
+.. code-block:: text
+
+ --USB Serial--+ +-----STM32F429 MCU-----
+ | |
+ TX o--->o PA10/USART1_RX
+ | |
+ RX o<---o PA9/USART1_TX
+ | |
+ --------------+ +-----------------------
Dependencies
============
