From: Robin Krens <robin@robinkrens.nl>
Date: Tue, 13 Aug 2019 19:05:58 +0000 (+0800)
Subject: rewrite register function, code formatting
X-Git-Url: https://robinkrens.nl/gitweb/?a=commitdiff_plain;h=9b56cc6635c4ca73be6d14a3492d7ce05bbd028e;p=cortex-from-scratch

rewrite register function, code formatting
---

diff --git a/drivers/tm1637.c b/drivers/tm1637.c
index 8c8ce5b..b6453ae 100644
--- a/drivers/tm1637.c
+++ b/drivers/tm1637.c
@@ -1,17 +1,24 @@
 /* (CC-BY-NC-SA) ROBIN KRENS - ROBIN @ ROBINKRENS.NL
  * 
  * $LOG$
- * 2019/7/25 - ROBIN KRENS	
+ * 2019/8/14 - ROBIN KRENS	
  * Initial version 
  * 
  * $DESCRIPTION$
- * Basic driver for the TM1637. The TM1637 is 8 segment
- * ledclock peripheral. Communication is similar to I2C,
- * but not completely. There is no address selecting.
+ * Driver for the TM1637 for STM32 boards. 
+ * The TM1637 is (4 digit) 8 segment ledclock peripheral. Communication 
+ * is similar to I2C, but not completely. There is no device address
+ * selecting. Instead, you can directly send a command / write data. 
  *
- * Alternative I2C protocol : (W)rite or (R)ead
- * | Start | ADDRESS | W | ACK/NACK | DATA | ACK/NACK | (d+a*n) | St
- * | Start | ADDRESS | R | ACK/NACK | DATA | ACK/NACK | (d+a*n) | St
+ * Most libraries for this chip that I have seen use 'Bit banging'.
+ * Manually adjusting the clock and data pin (not using the I2C)
+ *
+ * This driver is different and uses STM32 I2C hardware. A problem of the
+ * TM1637 chip, however, is that commands sometimes set bit 1 (LSB). Setting
+ * the LSB will make the STM32 MCU switch to receiver mode. (A better design 
+ * choice for commands would have to keep the LSB reserved). 
+ *
+ * Another thing to note is that this chip uses BIG-ENDIANESS
  *
  * */
 
@@ -24,7 +31,7 @@
 
 #include <lib/regfunc.h>
 #include <lib/string.h>
-#include <lib/stdio.h>
+#include <lib/tinyprintf.h>
 
 #include <drivers/tm1637.h>
 
@@ -33,90 +40,142 @@
 #define DOT true
 #define NODOT false
 
-
-/* 
-0 = 0x00
-1 = 0x60
-2 = 0xDA
-3 = 0xF2
-4 = 0x66
-5 = 0xB6
-6 = 0xBE
-7 = 0xE0
-8 = 0xFF
-9 = 0xF6
-*/
+#define WRITE_CMD 0x20
 
 /* STM32F1 microcontrollers do not provide the ability to pull-up SDA and SCL lines. Their
 GPIOs must be configured as open-drain. So, you have to add two additional resistors to
 pull-up I2C lines. Something between 4K and 10K is a proven value.
 */
 
-/* BIG ENDIAN! */
-
 void tm1637_init() {
 
- /* Program the peripheral input clock in I2C_CR2 Register in order to generate correct timings
- Configure the clock control registers CCR
- Configure the rise time register TRIS
- Program the I2C_CR1 register to enable the peripheral
+ /* Program the peripheral input clock generate correct timings.
+  * Configure the clock control registers CCR
+  * Configure the rise time register TRIS
+  * Program the I2C_CR1 register to enable the peripheral
+  * Enable GPIOB6 and B7*/
+ 
+ rsetbit(RCC_APB1ENR, 21); // enable GPIOB
+ rsetbit(RCC_APB2ENR, 3); // enable I2C
+ rwrite(GPIOB_CRL, 0xEE444444); // open-drain
+ rsetbitsfrom(I2C_CR2, 0, 0x2); // 2 MHz 
+ rwrite(I2C_TRISE, 0x3); // MAX = 1000ns, TPCLK1 = 500ns (+1)
+ rwrite(I2C_CCR, 0x000A); // standard mode
+ rsetbit(I2C_CR1, 0); // enable
 
- ENABLE GPIOB6 and B7*/
+}
 
- regw_u32(RCC_APB1ENR, 0x1, 21, SETBIT);
- regw_u32(RCC_APB2ENR, 0x1, 3, SETBIT);
- // //regw_u8(AFIO_EVCR, 0x89, 0, SETBIT);// set event control register, output on ?
- 
- regw_u32(GPIOB_CRL, 0xEE444444, 0, OWRITE);
+/* Reset the I2C channels and reinitialize */
+void tm1637_reset() {
+
+ rsetbit(I2C_CR1, 15); // master is busy, reset
+ rsetbit(RCC_APB1RSTR, 21); // reset I2C
+ rwrite(RCC_APB1RSTR, 0x00000000); // clear reset
+ rsetbit(RCC_APB1ENR, 21);
+ rsetbitsfrom(I2C_CR2, 0, 0x2); // 2 MHz 
+ rwrite(I2C_TRISE, 0x3); // MAX = 1000ns, TPCLK1 = 500ns (+1)
+ rwrite(I2C_CCR, 0x000A); // standard mode
+ rsetbit(I2C_CR1, 0); // enable
 
- regw_u32(I2C_CR2, 0x2, 0, OWRITE); //2 MHz 
- regw_u8(I2C_TRISE, 0x3, 0, OWRITE); // MAX = 1000ns, TPCLK1 = 500ns (+1)
- regw_u32(I2C_CCR, 0x000A, 0, OWRITE); // standard mode, output 100 kHz (100hz* / perip)
- 
- regw_u32(I2C_CR1, 0x1, 0, OWRITE); // enable
 
 }
 
-void tm1637_reset() {
+/* Write value to grid, if no offset is given it writes to the first
+ * grid. Grid 1 an 2 have an additional dot that can be set */
+int set_grid(uint8_t offset, char value, bool dot) {
 
- regw_u32(RCC_APB1RSTR, 0x1, 21, SETBIT);
+	//int (*ack)() = ack_recv; /* Scary function pointer :D */
 
- regw_u32(RCC_APB1RSTR, 0x00000000, 0, OWRITE); // clr
- //regw_u32(RCC_APB2ENR, 0x1, 3, SETBIT);
- // //regw_u8(AFIO_EVCR, 0x89, 0, SETBIT);// set event control register, output on ?
- 
- regw_u32(RCC_APB1ENR, 0x1, 21, SETBIT);
- //regw_u32(GPIOB_CRL, 0xEE444444, 0, OWRITE);
+	if (offset > 3) {
+		printf("Offset incorrect");
+	}
+
+	// enable dot on display if desired
+	if (dot && (offset == 1 || offset == 2)) {
+		value = value | 0x1;
+	}
+
+	int start_pos_cmd  = 0x03  | (offset & 0x01) << 7 | (offset & 0x2) << 5 ;
+
+	/* Initiate writing routine */
+	start_condition();
+	rwrite(I2C_DR, WRITE_CMD); 
+	if(!ack_recv())
+		return -1;
+
+	stop_condition();
+	
+       	if(!idle())
+		return -1;
+
+	/* Set GRID offset */
+	start_condition();
+	rwrite(I2C_DR, start_pos_cmd); 
+	if(!ack_recv())
+		return -1;
+
+	stop_condition();
 
- regw_u32(I2C_CR2, 0x2, 0, OWRITE); //2 MHz 
- regw_u8(I2C_TRISE, 0x3, 0, OWRITE); // MAX = 1000ns, TPCLK1 = 500ns (+1)
- regw_u32(I2C_CCR, 0x000A, 0, OWRITE); // standard mode, output 100 kHz (100hz* / perip)
+	tm1637_reset();
 
- regw_u32(I2C_CR1, 0x1, 0, OWRITE); // enable
+	/* Write value to segments */
+	start_condition();
+	rwrite(I2C_DR, value);
+	if(!ack_recv())
+		return -1;
+	stop_condition(); 
 
+	tm1637_reset();
 
+	return 0;
 }
 
-static void start_condition() {
+/* Turns on/off the led display. The degree of brightness can set [0..7]*/
+int set_display(bool on, uint8_t degree) {
+
+	int disp_cmd = 0x1; // off
+        if (on) {
+		disp_cmd = 0xF1; // TODO 
+	}	
 
-	regw_u32(I2C_CR1, 0x1, 8, SETBIT); //start
+	start_condition();
+	rwrite(I2C_DR, disp_cmd);
+	if(!ack_recv()) {
+		printf("Can't switch on display!");
+		return -1;
+	}
+	stop_condition();
+
+	tm1637_reset();
+
+	return 0;
 
 }
 
-static void stop_condition() {
 
-	regw_u32(I2C_CR1, 0x1, 9, SETBIT); //stop
+void tm1637_example() {
+
+unsigned char display_number[10] = {0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0, 0xFE, 0xF6};
+
+
+	char love[4]  = { 0x1C, 0xFC, 0x7C, 0x9E };
+	
+	for (int i = 0; i < 4; i++) {
+		set_grid(i, love[i], NODOT);
+	}
+
+	set_display(true, 0);
+
 }
 
-static int buf_empty() {
-        int cnt = 0;
-        while(!(*I2C_SR1 & 0x80)) {
-                cnt++;
-                if (cnt > TIMEOUT) {
-                        return 0;
-                }
-        }
-        return 1;
+/* HELPER ROUTINES */
+
+static void start_condition() {
+	rsetbit(I2C_CR1, 8); //start bit
+}
+
+static void stop_condition() {
+	rsetbit(I2C_CR1, 9); //stop bit
 }
 
 /* Wait for an acknowledge from the peripheral */
@@ -124,8 +183,10 @@ int ack_recv() {
 	int cnt = 0;
 	while(!(*I2C_SR1 & 0x2)) {
 		cnt++;
-		if (cnt > TIMEOUT)
+		if (cnt > TIMEOUT) {
+			printf("Error: no ack (addr bit) received \n");
 			return 0;
+		}
 	}
 	uint32_t a = *I2C_SR2; // need to read SR2 register!
 	return 1;
@@ -137,110 +198,27 @@ int ack10_recv() {
 	int cnt = 0;
 	while(!(*I2C_SR1 & 0x8)) {
 		cnt++;
-		if (cnt > TIMEOUT)
+		if (cnt > TIMEOUT) {
+			printf("Error: no ack (addr10 bit) received \n");
 			return 0;
+		}
 	}
 	return 1;
 
 }
 
+/* Check if lines are idle (i.e. stop condition finished)*/
 int idle() {
 	int cnt = 0;
 	while(*I2C_SR2 & 0x2) {
 		cnt++;
-		if (cnt > TIMEOUT)
+		if (cnt > TIMEOUT) {
+			printf("Error: busy state\n");
 			return 0;
+		}
 	}
 
 	return 1;
 }
 
-int delay() {
-
-	int a = 0;
-	for (int i = 0; i < TIMEOUT; i++)
-		a++;
-}
-
-void set_display(bool on, uint8_t degree) {
-
-	start_condition();
-
-	regw_u32(I2C_DR, 0xF1, 0, OWRITE);
-	if(!ack_recv())
-		cputs("Can't switch on display!");
-	stop_condition();
-
-	// reset bus
-	regw_u32(I2C_CR1, 0x1, 15, SETBIT);
-
-}
-
-
-void set_segment(int offset, char value, bool dot) {
-
-	int (*ack)() = ack_recv; /* Scary function pointer :D */
-
-
-	if (offset > 3) {
-		cputs("Offset incorrect");
-	}
-
-	if (dot) {
-		value = value | 0x1;
-	}
-	int start_pos_cmd  = 0x03  | (offset & 0x01) << 7 | (offset & 0x2) << 5 ;
-
-	start_condition();
-	regw_u32(I2C_DR, 0x20, 0, OWRITE); 
-	if(!ack_recv())
-		cputs("Error: initiating write for start segment \n");
-
-	stop_condition();
-	
-       	if(!idle())
-		cputs("Error: timeout");
-
-
-	start_condition();
-	regw_u32(I2C_DR, start_pos_cmd, 0, OWRITE); 
-	if(!ack())
-		cputs("Error: Can't set start segment \n");
-
-	stop_condition();
-	regw_u32(I2C_CR1, 0x1, 15, SETBIT);
-
-	tm1637_reset();
-
-//	if (value & 0xF0)
-//		ack = &ack10_recv;
-
-	start_condition();
-	regw_u32(I2C_DR, value, 0, OWRITE); // use ack10 if higher
-	if(!ack_recv())
-		cputs("Error: can't set location\n");
-	stop_condition(); 
-
-	regw_u32(I2C_CR1, 0x1, 15, SETBIT);
-
-	tm1637_reset();
-}
-
-
-
-void tm1637_start() {
-
-unsigned char display_number[10] = {0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0, 0xFE, 0xF6};
-
-
-	char love[4]  = { 0x1C, 0xFC, 0x7C, 0x9E };
-	
-	for (int i = 0; i < 4; i++) {
-		set_segment(i, love[i], NODOT);
-	}
-
-	set_display(true, 0);
-
-}
-
 
diff --git a/include/drivers/tm1637.h b/include/drivers/tm1637.h
index 4ad572a..e537cdf 100644
--- a/include/drivers/tm1637.h
+++ b/include/drivers/tm1637.h
@@ -1,8 +1,16 @@
 #ifndef __TM1637_H
 #define __TM1637_H
 
+/* HELPER SUBROUTINES DECLARATIONS */
+static void start_condition();
+static void stop_condition();
+static int ack_recv();
+static int ack10_recv();
+static int idle();
+
 extern void tm1637_init();
-extern void tm1637_start();
-extern void tm1637_stop();
+extern int set_grid(uint8_t offset, char value, bool dot);
+extern int set_display(bool on, uint8_t degree);
+extern void tm1637_example();
 
 #endif
diff --git a/include/sys/robsys.h b/include/sys/robsys.h
index 9a19a47..6962770 100644
--- a/include/sys/robsys.h
+++ b/include/sys/robsys.h
@@ -8,7 +8,7 @@
  * These values are used throughout the code to calculator desired baud
  * rates etc.
  */
-//#define ENABLE_HSE	
+//#define ENABLE_HSE 		
 //efine CRYSTAL_MHZ 	8
 //efine CLKSPEED_MHZ 	72
 extern void clock_init();
diff --git a/main.c b/main.c
index 8455b46..68eaa03 100644
--- a/main.c
+++ b/main.c
@@ -69,10 +69,10 @@ void main()
 	led_init();
 //	eeprom_at24c_init();
 //	eeprom_test();
-//	rtc_init();
+	rtc_init();
 
 	tm1637_init();
-	tm1637_start();
+	tm1637_example();
 
 	//uint32_t test = hextoreg("12345678");