add bluepill mcu to splittest (#16959)

* add bluepill mcu to splittest

* fix typo

* refactoring

* mcu config goes to mcuconf.h of keyboard
* keymap specific config goes to keymap config.h
* keyboard specific depending of keymap goes to post_config.h

* Apply suggested change

Co-authored-by: Ryan <fauxpark@gmail.com>

* Apply suggested change

Co-authored-by: Ryan <fauxpark@gmail.com>

* Apply suggested change

Co-authored-by: Ryan <fauxpark@gmail.com>

* Apply suggested change

Co-authored-by: Ryan <fauxpark@gmail.com>

* Apply suggested change

Co-authored-by: Ryan <fauxpark@gmail.com>

* splittest/bluepill: improve documentation

Co-authored-by: Ryan <fauxpark@gmail.com>

7 files changed, 169 insertions, 0 deletions

diff --git a/keyboards/handwired/splittest/bluepill/chconf.h b/keyboards/handwired/splittest/bluepill/chconf.h
new file mode 100644
index 0000000000..73c7d64e3a
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/chconf.h
@@ -0,0 +1,23 @@
+/* Copyright 2020 QMK
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#define CH_CFG_ST_TIMEDELTA 0
+
+#define CH_CFG_USE_CONDVARS_TIMEOUT FALSE
+
+#include_next <chconf.h>
diff --git a/keyboards/handwired/splittest/bluepill/config.h b/keyboards/handwired/splittest/bluepill/config.h
new file mode 100644
index 0000000000..92766b3de4
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/config.h
@@ -0,0 +1,16 @@
+// Copyright 2022 dvermd (@dvermd)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "config_common.h"
+
+// wiring of each half
+#define MATRIX_ROW_PINS { B10 }
+#define MATRIX_COL_PINS { B1 }
+
+#define SPLIT_HAND_PIN A7
+
+#if !(defined(USE_SDI1_ON_STANDARD_ROLE_PINS) || defined(USE_SDI1_ON_ALTERNATE_ROLE_PINS) || defined(USE_SDI2))
+    #define USE_SDI1_ON_STANDARD_ROLE_PINS
+#endif
\ No newline at end of file
diff --git a/keyboards/handwired/splittest/bluepill/halconf.h b/keyboards/handwired/splittest/bluepill/halconf.h
new file mode 100644
index 0000000000..d85c8b842e
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/halconf.h
@@ -0,0 +1,6 @@
+/* Needed for serial bitbang, half-duplex and full-duplex */
+#define HAL_USE_PAL TRUE
+#define PAL_USE_WAIT TRUE
+#define PAL_USE_CALLBACKS TRUE
+
+#include_next <halconf.h>
diff --git a/keyboards/handwired/splittest/bluepill/mcuconf.h b/keyboards/handwired/splittest/bluepill/mcuconf.h
new file mode 100644
index 0000000000..875819537f
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/mcuconf.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include_next <mcuconf.h>
+
+// These are needed if the communication is on the SD1 USART, either with standard or alternate pins
+#undef STM32_SERIAL_USE_USART1
+#define STM32_SERIAL_USE_USART1 TRUE
+
+// These are needed if the communication is on the SD2 USART, either with standard or alternate pins
+#undef STM32_SERIAL_USE_USART2
+#define STM32_SERIAL_USE_USART2 TRUE
diff --git a/keyboards/handwired/splittest/bluepill/post_config.h b/keyboards/handwired/splittest/bluepill/post_config.h
new file mode 100644
index 0000000000..b866805a64
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/post_config.h
@@ -0,0 +1,38 @@
+
+#if defined(SPLIT_BITBANG)
+
+    #define SOFT_SERIAL_PIN B8
+
+#elif defined(SPLIT_SERIAL_HALFDUPLEX)
+
+    #if defined(USE_SDI1_ON_STANDARD_ROLE_PINS)
+        #define SOFT_SERIAL_PIN A9
+    #elif defined(USE_SDI1_ON_ALTERNATE_ROLE_PINS)
+        #define SOFT_SERIAL_PIN B6
+        #define USART1_REMAP // Remap USART TX and RX pins on STM32F103 MCUs
+    #elif defined(USE_SDI2)
+        #define SOFT_SERIAL_PIN A2
+        #define SERIAL_USART_DRIVER SD2 // USART driver of TX and RX pin. default: SD1
+    #else
+        #error "splittest serial_halfduplex keymap is missing a configuration (USE_SDI1_ON_STANDARD_ROLE_PINS, USE_SDI1_ON_ALTERNATE_ROLE_PINS, USE_SDI2)"
+    #endif
+
+#elif defined(SPLIT_SERIAL_FULLDUPLEX)
+
+    #define SERIAL_USART_FULL_DUPLEX // Enable full duplex operation mode.
+
+    #if defined(USE_SDI1_ON_STANDARD_ROLE_PINS)
+        #define SOFT_SERIAL_PIN A9
+        #define SERIAL_USART_RX_PIN A10 // USART RX pin
+    #elif defined(USE_SDI1_ON_ALTERNATE_ROLE_PINS)
+        #define SOFT_SERIAL_PIN B6
+        #define SERIAL_USART_RX_PIN B7 // USART RX pin
+        #define USART1_REMAP           // Remap USART TX and RX pins on STM32F103 MCUs
+    #elif defined(USE_SDI2)
+        #define SOFT_SERIAL_PIN A2
+        #define SERIAL_USART_RX_PIN A3  // USART RX pin
+        #define SERIAL_USART_DRIVER SD2 // USART driver of TX and RX pin. default: SD1
+    #else
+        #error "splittest serial_fullduplex keymap is missing a configuration (USE_SDI1_ON_STANDARD_ROLE_PINS, USE_SDI1_ON_ALTERNATE_ROLE_PINS, USE_SDI2)"
+    #endif
+#endif
diff --git a/keyboards/handwired/splittest/bluepill/readme.md b/keyboards/handwired/splittest/bluepill/readme.md
new file mode 100644
index 0000000000..381aa6ba3a
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/readme.md
@@ -0,0 +1,65 @@
+# bluepill splittest
+
+This is the splittest example for the bluepill MCU.
+To trigger keypress, short together pins _B10_ and _B1_.
+
+## Keyboard Configuration
+
+The type of communication (bitbang, serial (half/full duplex)) is set by the keymap `config.h` file with variables with `SPLIT_` prefix.
+So this example uses:
+
+-   `config.h` to set which SDI to use for serial. Either define `USE_SDI1_ON_STANDARD_ROLE_PINS`, `USE_SDI1_ON_ALTERNATE_ROLE_PINS` or `USE_SDI2` before the `#ifdef` that configures the default case when none of these variable is defined.
+-   `post_config.h` for defining the communication pins between the halves once the keymap is configured.
+
+On your keyboard, you most likely will only use `config.h` because you'd have already chosen your communication scheme: serial type, SDI, pins.
+
+## Wiring
+
+### Switches
+
+-   Add switches to both Bluepills across B10 and B1 pins
+
+### Handedness
+
+Have a look at the [handedness documentation](https://docs.qmk.fm/#/feature_split_keyboard?id=setting-handedness)
+
+-   Add pull-up resistor to left side between VCC and A7
+-   Add pull-down resistors to right side between GND and A7
+
+### Send power to the other half
+
+-   Connect the following pins on both sides together: GND, VCC
+
+### Halves data connection
+
+Choose one of the connection type
+
+#### serial - bitbang
+
+-   Connect the B8 pins on both sides together
+
+#### serial - usart half duplex
+
+Check the [documentation](https://docs.qmk.fm/#/serial_driver?id=usart-half-duplex) to determine the pull-up resistor.
+
+-   To use the default usart (USART1) with the standard role pins,
+    -   Connect the A9 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI1_ON_STANDARD_ROLE_PINS in config.h
+-   To use the default usart (USART1) with the alternate role pins,
+    -   Connect the B6 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI1_ON_ALTERNATE_ROLE_PINS in config.h
+-   To use the usart2 (USART2) pins,
+    -   Connect the A2 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI2 in config.h
+
+#### serial - usart full duplex
+
+-   To use the default usart (USART1) with the standard role pins,
+    -   Connect the mpins on A9, A10 one to the other on each side
+    -   Define USE_SDI1_ON_STANDARD_ROLE_PINS in config.h
+-   To use the default usart (USART1) with the alternate role pins,
+    -   Connect the pins B6, B7 one to the other on each side
+    -   Define USE_SDI1_ON_ALTERNATE_ROLE_PINS in config.h
+-   To use the usart2 (USART2) pins,
+    -   Connect the pins A2, A3 one to the other on each side
+    -   Define USE_SDI2 in config.h
diff --git a/keyboards/handwired/splittest/bluepill/rules.mk b/keyboards/handwired/splittest/bluepill/rules.mk
new file mode 100644
index 0000000000..1d2ff9419e
--- /dev/null
+++ b/keyboards/handwired/splittest/bluepill/rules.mk
@@ -0,0 +1,10 @@
+# MCU name
+MCU = STM32F103
+
+# Bootloader selection
+BOOTLOADER = stm32duino
+
+CONSOLE_ENABLE = yes
+
+# Enter lower-power sleep mode when on the ChibiOS idle thread
+OPT_DEFS += -DCORTEX_ENABLE_WFI_IDLE=TRUE