added some better comments to ADC example

Makefile

@@ -20,7 +20,7 @@
 PREFIX		?= arm-none-eabi
 #PREFIX		?= arm-elf
 
-TARGETS = stm32/f1 stm32/f2 stm32/f4 stm32/l1 lpc13xx lpc17xx lpc43xx lm3s lm4f efm32/efm32tg efm32/efm32g efm32/efm32lg efm32/efm32gg
+TARGETS = stm32/f1 stm32/f2 stm32/f3 stm32/f4 stm32/l1 lpc13xx lpc17xx lpc43xx lm3s lm4f efm32/efm32tg efm32/efm32g efm32/efm32lg efm32/efm32gg
 
 # Be silent per default, but 'make V=1' will show all compiler calls.
 ifneq ($(V),1)

examples/stm32/f3/stm32f3-discovery/adc/README

@@ -4,6 +4,10 @@ README
 
 This is the smallest-possible example program using libopencm3.
 
-It's intended for the ST STM32F3DISCOVERY eval board. It should read from the ADC1_IN1 (PA0) pin its voltage and print it in the LEDs.
+It's intended for the ST STM32F3DISCOVERY eval board. It should read from 
+the ADC1_IN1 (PA0) pin its voltage and print it in decimal on UART3 
+(baud rate?) and show it in the LEDs (in binary).
 
+The code can easily be changed to show the internal temperature
+sensor instead. 
 

examples/stm32/f3/stm32f3-discovery/adc/adc.c

@@ -59,9 +59,13 @@ void adc_setup(void) {
         /* We want to read the temperature sensor, so we have to enable it. */
         adc_enable_temperature_sensor();
         adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR1_SMP_61DOT5CYC);
-	uint8_t channel_array[16];
-	channel_array[0]=16; // Vts (Internal temperature sensor
+
+	uint8_t channel_array[16]; // full array, but this example only uses one entry. 
+
+	// select the channel you want to sample here: 
+	//channel_array[0]=16; // Vts (Internal temperature sensor
 	channel_array[0]=1; //ADC1_IN1 (PA0)
+
 	adc_set_regular_sequence(ADC1, 1, channel_array);
 	adc_set_resolution(ADC1, ADC_CFGR_RES_12_BIT);
         adc_power_on(ADC1);

examples/stm32/f3/stm32f3-discovery/usart/Makefile

@@ -0,0 +1,25 @@
+##
+## 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 = usart
+
+LDSCRIPT = ../stm32f3-discovery.ld
+
+include ../../Makefile.include
+

examples/stm32/f3/stm32f3-discovery/usart/README

@@ -0,0 +1,29 @@
+------------------------------------------------------------------------------
+README
+------------------------------------------------------------------------------
+
+This example program sends some characters on USART2 on the
+ST STM32F3DISCOVERY eval board.
+
+The terminal settings for the receiving device/PC are 115200 8n1.
+
+The sending is done in a blocking way in the code.
+
+The program also recieves characters and prints them with <> around
+the recieved characters. 
+
+If an overrun happens "R" is printed, and the flag is cleard to reenable
+reception. 
+
+If a framing error happens "F" is printed, and the flag is cleard to reenable
+reception. 
+
+If a parity error happens "R" is printed, and the flag is cleard to reenable
+reception. (this cannot currently happen as parity is disabled). 
+
+
+TODO: Figure out why
+- the baud rate passed to set_baudrate is 1/4 of what is wanted. 
+- the RDR is called RDR here in the code and in my datasheet, but the 
+library code seems to want to use "DR" which I can't find anywhere. 
+

examples/stm32/f3/stm32f3-discovery/usart/usart.c

@@ -0,0 +1,112 @@
+/*
+ * 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/>.
+ */
+
+#include <libopencm3/stm32/f4/rcc.h>
+#include <libopencm3/stm32/f4/gpio.h>
+#include <libopencm3/stm32/usart.h>
+#include <stdarg.h>
+
+
+static void clock_setup(void)
+{
+	/* Enable GPIOD clock for LED & USARTs. */
+	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);
+	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);
+
+	/* Enable clocks for USART2. */
+	rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+}
+
+static void usart_setup(void)
+{
+	/* Setup USART2 parameters. */
+
+  // XXX TODO: figure out why the number passed is /4 for STM32F3. 
+	usart_set_baudrate(USART2, 115200/4);
+	usart_set_databits(USART2, 8);
+	usart_set_stopbits(USART2, USART_STOPBITS_1);
+	usart_set_mode(USART2, USART_MODE_TX | USART_MODE_RX);
+	usart_set_parity(USART2, USART_PARITY_NONE);
+	usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
+
+	USART_ICR (USART2) = USART_ICR_ORECF | USART_ICR_FECF;
+
+	/* Finally enable the USART. */
+	usart_enable(USART2);
+}
+
+static void gpio_setup(void)
+{
+	/* Setup GPIO pin GPIO12 on GPIO port D for LED. */
+	gpio_mode_setup(GPIOE, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO12);
+
+	/* Setup GPIO pins for USART2 transmit. */
+	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2|GPIO3);
+
+	/* Setup USART2 RX/TX pins as alternate function. */
+	gpio_set_af(GPIOA, GPIO_AF7, GPIO2 | GPIO3);
+}
+
+
+int main(void)
+{
+	int i, j = 0, c = 0;
+
+	clock_setup();
+	gpio_setup();
+	usart_setup();
+
+	/* Blink the LED (PE12) on the board with every transmitted byte. */
+	while (1) {
+		gpio_toggle(GPIOE, GPIO12);	/* LED on/off */
+		usart_send_blocking(USART2, c + '0'); /* USART2: Send byte. */
+		c = (c == 9) ? 0 : c + 1;	/* Increment c. */
+
+		// The original finished the line at 80 chars. 39 gives
+		// a nice twirl effect and allows for reception characters
+		// to be printed inbetween. 
+		if ((j++ % 39) == 0) {		/* Newline after line full. */
+			usart_send_blocking(USART2, '\r');
+			usart_send_blocking(USART2, '\n');
+		}
+		for (i = 0; i < 300000; i++)	/* Wait a bit. */
+			__asm__("NOP");
+
+		if ((USART_ISR(USART2) & USART_ISR_RXNE) != 0) {
+		  usart_send_blocking (USART2, '<');
+		  usart_send_blocking (USART2, USART_RDR(USART2));
+		  usart_send_blocking (USART2, '>');
+		}
+		if ((USART_ISR(USART2) & USART_ISR_ORE) != 0) {
+		  USART_ICR (USART2) = USART_ICR_ORECF;
+		  usart_send_blocking (USART2, 'R');
+		}
+		if ((USART_ISR(USART2) & USART_ISR_PE) != 0) {
+		  USART_ICR (USART2) = USART_ICR_PECF;
+		  usart_send_blocking (USART2, 'P');
+		}
+		if ((USART_ISR(USART2) & USART_ISR_FE) != 0) {
+		  USART_ICR (USART2) = USART_ICR_FECF;
+		  usart_send_blocking (USART2, 'F');
+		}
+	}
+
+	return 0;
+}