Added stm32 app.

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "libopencm3"]
+	path = libopencm3
+	url = https://github.com/libopencm3/libopencm3.git

readme.md

@@ -12,7 +12,7 @@ cd pl02-fw
 west update
 ```
 
-### Build & Run - ESP32
+### Build & Run - ESP32/RP2040
 The application can be built by running:
 
 ```shell
@@ -31,3 +31,17 @@ west flash --runner jlink --build-dir build/rp2040
 # If you don't have a jlink (programmer). You can use this.
 sudo picotool load build/rp2040/zephyr/zephyr.elf
 ```
+
+### Build & Run - STM32
+The STM32 doesn't not used zephyr, it's a libopencm3 project.
+```shell
+git submodule init
+git submodule update
+```
+
+Building and flashing
+```shell
+cd stm32-app
+make
+make flash
+```

rp2040-app/src/main.cpp

@@ -97,7 +97,6 @@ void buckboost(void)
                 first = false;
             }
 
-
             // Read vbat in mA
             vbat = adc.read_vbat();
             if(vbat > 20000.0) {

stm32-app/Makefile

@@ -0,0 +1,47 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <[email protected]>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library 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 Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = main
+CSTD = -std=gnu99
+
+LDSCRIPT = nucleo-g030f6.ld
+LIBNAME		= opencm3_stm32g0
+DEFS		+= -DSTM32G0
+
+FP_FLAGS	?= -msoft-float
+ARCH_FLAGS	= -mthumb -mcpu=cortex-m0 $(FP_FLAGS)
+
+################################################################################
+# OpenOCD specific variables
+
+OOCD		?= openocd
+OOCD_INTERFACE	?= stlink
+OOCD_TARGET	?= stm32g0x
+
+################################################################################
+# Black Magic Probe specific variables
+# Set the BMP_PORT to a serial port and then BMP is used for flashing
+BMP_PORT	?=
+
+################################################################################
+# texane/stlink specific variables
+#STLINK_PORT	?= :4242
+
+
+include rules.mk

stm32-app/README.md

@@ -0,0 +1,12 @@
+# README
+
+This example program sends a message "Pass: n" with increasing number n
+from 0 to 200 on USART2 serial line of ST NUCLEO-G031K8 eval board.
+
+The sending is done using newlib library in a blocking way.
+
+## Board connections
+
+| Port  | Function      | Description                       |
+| ----- | ------------- | --------------------------------- |
+| `PA2` | `(USART2_TX)` | TTL serial output `(115200,8,N,1)` |

stm32-app/main.c

@@ -0,0 +1,69 @@
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/usart.h>
+
+#include <stdio.h>
+
+#define PORT_LED GPIOA
+#define PIN_LED1 GPIO5
+#define PIN_LED2 GPIO7
+
+void uart_out(char* data);
+
+static void clock_setup(void)
+{
+    /* Enable GPIOC clock for LED & USARTs. */
+    rcc_set_sysclk_source(RCC_CLOCK_CONFIG_HSI_PLL_64MHZ);
+    rcc_periph_clock_enable(RCC_GPIOA);
+    // rcc_periph_clock_enable(RCC_GPIOC);
+
+    /* Enable clocks for USART. */
+    // rcc_periph_clock_enable(RCC_USART1);
+}
+
+static void usart_setup(void)
+{
+    /* Setup USART parameters. */
+    usart_set_baudrate(USART1, 115200);
+    usart_set_databits(USART1, 8);
+    usart_set_parity(USART1, USART_PARITY_NONE);
+    usart_set_stopbits(USART1, USART_CR2_STOPBITS_1);
+    usart_set_mode(USART1, USART_MODE_TX);
+    usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
+
+    /* Finally enable the USART. */
+    usart_enable(USART1);
+}
+
+static void gpio_setup(void)
+{
+    gpio_mode_setup(PORT_LED, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, PIN_LED1 | PIN_LED2);
+
+    // gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9);
+
+    // gpio_set_af(GPIOA, GPIO_AF1, GPIO9);
+}
+
+void uart_out(char* data) {
+    while(*data) {
+        usart_send_blocking(USART1, *data++); /* USART2: Send byte. */
+    }
+}
+
+int main(void)
+{
+    int i = 0;
+    // char buf[256];
+
+    clock_setup();
+    gpio_setup();
+    // usart_setup();
+    // sprintf(buf, "Hello world\r\n");
+    // uart_out(buf);
+
+    while(1) {
+        gpio_set(PORT_LED, PIN_LED1 | PIN_LED2);
+    }
+
+    return 0;
+}

stm32-app/nucleo-g030f6.ld

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <[email protected]>
+ * Copyright (C) 2011 Stephen Caudle <[email protected]>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Linker script for ST NUCLEO-G030F6 (STM32G030F6, 32K flash, 8K RAM). */
+
+/* Define memory regions. */
+MEMORY
+{
+    rom (rx) : ORIGIN = 0x08000000, LENGTH = 32K
+	ram (rwx) : ORIGIN = 0x20000000, LENGTH = 8K
+}
+
+/* Include the common ld script. */
+INCLUDE cortex-m-generic.ld
+