/* (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
*
* */
#include <lib/regfunc.h>
#include <lib/string.h>
-#include <lib/stdio.h>
+#include <lib/tinyprintf.h>
#include <drivers/tm1637.h>
#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 */
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;
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);
-
-}
-
projects / cortex-from-scratch / commitdiff