From fac4700036ceaafe0d4a2b40d4c9f590d3c407b7 Mon Sep 17 00:00:00 2001 From: Robin Krens Date: Tue, 10 Sep 2019 20:43:53 +0700 Subject: [PATCH] printid and get_temp implementation --- drivers/tsensor.c | 498 +++++++++++++--------------------------------- include/drivers/tsensor.h | 10 +- main.c | 4 +- 3 files changed, 148 insertions(+), 364 deletions(-) diff --git a/drivers/tsensor.c b/drivers/tsensor.c index 9545e98..079d309 100644 --- a/drivers/tsensor.c +++ b/drivers/tsensor.c @@ -2,10 +2,28 @@ * * $LOG$ * 2019/8/28 - ROBIN KRENS - * PreInitial version + * Initial version * * $DESCRIPTION$ - * TIMERS, non-blocking... + * DS18B20 temperature sensor implementation + * Uses the 1-wire protocol. You will need to setup the temperature sensor + * with an external pull up resistor. High is the idle state of the chip. + * This implementation does not use parasite power. Uses busy waits. + * The chip doesn't require too accurate timings. Busy waits are between 15 + * and 240 microseconds. + * + * The temperature conversion on the chip it takes a lot longer (up to 700ms). + * In case temperature is often read, implementing this with interrupts might be + * worthwile. + * + * Each series of commands is initiated with a long reset and prescence pulse. + * Implemented: + * - Read ID of Chip + * - Convert and read temperature + * + * TODO: + * - Scratchpad copy functionality (+EEPROM) + * - Alarm functionality * * */ @@ -22,358 +40,115 @@ #include -#define PRESCALER 8 // 1 MHz (1 microsecond) -#define MAXBUF 10 - -int cnt; -enum status { INIT, WAIT_INIT, INIT_DONE } current_status; -enum rstatus { READ, READ_INIT, READ_DONE } read_status; - -static struct { - uint8_t buf[MAXBUF]; - uint8_t pos; -} readbuf; - -static struct { - char cmd; - uint8_t pos; -} sensor_cmd; - -// -void read_init(); +/* Commands */ +#define READ_ROM 0x33 +#define SKIP_ROM 0xCC +#define READ_SCRATCH 0xBE +#define CONVERT_T 0x44 +/* Basic GPIO settings for output pulses and input */ static void in_conf() { rwrite(GPIOB_CRL, 0x44444444); } static void out_conf() { - rwrite(GPIOB_CRL, 0x46444444); // open drain (with pullup resistor) -} - -/* set preload and generate update event */ -static void timer_config(uint16_t preload) { - rwrite(TIM4_ARR, preload); - rsetbit(TIM4_EGR, 0); -} - -static void presence_pulse_conf() { - - current_status = INIT; - out_conf(); - rclrbit(GPIOB_ODR, 6); // low - timer_config(480); // > 480 us -} - -static void presence_reply_conf() { - - current_status = WAIT_INIT; - in_conf(); - timer_config(60); // > 60 us -} - -static void finish_init() { - current_status = INIT_DONE; - timer_config(480); -} - -/* Handlers for read, write and init pulses */ - -void * write_handler() { - - - - // i - // in_conf(); - - - - rclrbit(TIM4_SR1, 0); - rclrbit(TIM4_SR1, 1); - if (sensor_cmd.pos < 7) { - - if ((sensor_cmd.cmd >> sensor_cmd.pos+1) & 0x01) { - printf("1\n"); - rwrite(TIM4_CCR1, 5); - rsetbit(TIM4_EGR, 0); - } - - else { - printf("0"); - rwrite(TIM4_CCR1, 60); - rsetbit(TIM4_EGR, 0); - - } - sensor_cmd.pos++; - } - else { - - read_init(); - } - + rwrite(GPIOB_CRL, 0x46444444); // open drain (with external pullup resistor) } -void * reply_handler() { - - - cnt++; - if (cnt > 16) { - for(;;); - } - - rclrbit(TIM4_SR1, 0); - rclrbit(TIM4_SR1, 1); - switch(read_status) { - case(READ_INIT): - in_conf(); - read_status = READ; - rsetbit(GPIOB_BSRR, 22); // low (<- reset) - if (rchkbit(GPIOB_IDR, 6)) { - printf("h\n"); - } - else { - printf("l\n"); - } - timer_config(60); - break; - case(READ): - out_conf(); - rclrbit(GPIOB_ODR, 6); // low - read_status = READ_INIT; - timer_config(1); - break; - case(READ_DONE): - // terminate - break; - } - - -} - - -void read_init() { - - - rclrbit(TIM4_CR1, 0); // stop - rclrbit(TIM4_CCER, 0); - rclrbit(TIM4_CCER, 1); - - //rwrite(GPIOB_CRL, 0x46444444); // floating - out_conf(); - rsetbit(TIM4_CR1, 2); // only overflow generates update - read_status = READ_INIT; - timer_config(1); // init 1us - - ivt_set_gate(46, reply_handler, 0); - rsetbit(NVIC_ISER0, 30); // interupt 41 - 32 - - //rclrbit(TIM4_DIER, 0); - - rclrbit(GPIOB_ODR, 6); // low - rsetbit(TIM4_DIER, 0); - - rsetbit(TIM4_CR1, 0); - -} - - -void write_init() { - - sensor_cmd.cmd = 0x33; - sensor_cmd.pos = 0; - - rsetbit(RCC_APB2ENR, 3); // GPIOB enable - rsetbit(RCC_APB1ENR, 2); // TIM4 enable - rsetbitsfrom(TIM4_CR1, 5, 0x00); // edge-aligned mode - rclrbit(TIM4_CR1, 4); // upcounter (clrbit! not needed to set) - rsetbit(TIM4_CR1, 2); // only overflow generates update - rwrite(TIM4_PSC, PRESCALER - 1); - rwrite(GPIOB_CRL, 0x4A444444); - - - timer_config(61); - - if ((sensor_cmd.cmd >> sensor_cmd.pos) & 0x01) { - printf("1\n"); - rwrite(TIM4_CCR1, 5); // < 15ms - } - else { - printf("0\n"); - rwrite(TIM4_CCR1, 60); - } - - rsetbitsfrom(TIM4_CCMR1, 4, 0x6); // forced high on match - - rsetbit(TIM4_CCER, 0); - rsetbit(TIM4_CCER, 1); - - // set write handler - ivt_set_gate(46, write_handler, 0); - rsetbit(NVIC_ISER0, 30); // interupt 41 - 32 - - //rsetbit(TIM4_DIER, 1); - rsetbit(TIM4_DIER, 0); - rsetbit(TIM4_CR1, 0); - -} - - -void * init_handler() { - - switch(current_status) { - case (INIT): - printf("M: reset\n"); - presence_reply_conf(); - break; - case (WAIT_INIT): - if (!rchkbit(GPIOB_IDR, 6)) { - printf("S: yes\n"); - } - else { - printf("S: no\n"); - } - finish_init(); - break; - - case (INIT_DONE): - printf("M: fin\n"); - write_init(); - break; - - default: - printf("no status\n"); - } - - rclrbit(TIM4_SR1, 0); -} - -/* TODO: write - * uint8_t cmd = 0x33 - * if (cmd & 0x01) - * 1 slot - * else 0 slot - * cmd = cmd >> 1 - * - * read, similar as pulse response */ - - -void * bare_handler() { - -//w2 cnt += 1; -//w2 printf("CHECKING STATUS\n"); -//w2 -//w2 if(rchkbit(GPIOB_IDR, 6)) { -//w2 printf("port high\n"); -//w2 } -//w2 else { -//w2 printf("port low\n"); -//w2 } - - - cnt += 1; - printf("Count event %d\n", cnt); - int switchled = cnt % 2; - if (switchled) { - rwrite(GPIOB_CRL, 0x46444444); // open drain general for sensor? - printf("setting low\n"); - rclrbit(GPIOB_ODR, 6); // low - } - else { - printf("pulling high \n"); - rwrite(GPIOB_CRL, 0x44444444); // open drain general for sensor? - //rsetbit(GPIOB_ODR, 6); // high - - } - rclrbit(TIM4_SR1, 0); -} - -void send_cmd(unsigned char cmd) { - +/* Send command cmd over data wire. Each write slot should be + * at least 60ms. */ +static void send_cmd(unsigned char cmd) { int pos = 0; for (int i = 0; i < 8; i++) { + // initiate write slot out_conf(); - rclrbit(GPIOB_ODR, 6); + rclrbit(GPIOB_ODR, 6); // pull low + + // writing a logical 1 or 0 if ((cmd >> pos) & 0x01) { _block(5); in_conf(); _block(60); - // printf("1"); } else { _block(60); in_conf(); - // printf("0"); } pos++; } } -void read_reply() { +/* Read reply of sensor. Depending on the command, the sensor + * can send back up to 9 bytes */ +static char get_byte() { + + char c = 0x00; - for (int i = 0; i < 64; i++) { + for (int i = 0; i < 8; i++) { + /* Initate write slot*/ out_conf(); rclrbit(GPIOB_ODR, 6); _block(3); + /* Listen for reply */ in_conf(); - if (rchkbit(GPIOB_IDR,6)) - { - printf("1"); - } + if (rchkbit(GPIOB_IDR,6)) { + c = c | (0x1 << i); + } else { - printf("0"); + c = c | (0x0 << i); } + /* Each read slot should be at least 60 microseconds + * before the next one is initiated */ _block(60); } - + return c; } -void tsensor_init() { + +/* Initiate the sensor, send a reset pulse and wait consequently for + * presence pulse. Slots should be at least 450 and 240 microseconds. + * */ +static int tsensor_init() { rsetbit(RCC_APB2ENR, 3); // GPIOB enable + + /* send presence pulse */ out_conf(); - rclrbit(GPIOB_ODR, 6); // loq + rclrbit(GPIOB_ODR, 6); // pull low _block(450); + /* wait for the chips reply */ in_conf(); _block(60); if (!rchkbit(GPIOB_IDR, 6)) { - printf("reply"); + //printf("Info: sensor detected\n"); + //get_id(); } else { - printf("nothing"); + printf("Error: no temperature sensor found!"); + return -1; } - _block(240); - - -// rsetbit(RCC_APB2ENR, 3); // GPIOB enable -// rsetbit(RCC_APB1ENR, 2); // TIM4 enable -// -// rsetbitsfrom(TIM4_CR1, 5, 0x00); // edge-aligned mode -// rclrbit(TIM4_CR1, 4); // upcounter (clrbit! not needed to set) -// rsetbit(TIM4_CR1, 2); // only overflow generates update -// -// rwrite(TIM4_PSC, PRESCALER - 1); -// presence_pulse_conf(); -//// rwrite(TIM4_ARR, preload); -//// rsetbit(TIM4_EGR, 0); -// -// ivt_set_gate(46, init_handler, 0); -// rsetbit(NVIC_ISER0, 30); // interupt 41 - 32 -// -////w rsetbit(GPIOB_ODR, 6); // -// rsetbit(TIM4_DIER, 0); -// rsetbit(TIM4_CR1, 0); // start + _block(240); // finish intialization slot + + return 0; } -void wait_for_sensor() { + + +/* Wait for the chip to convert the temperature */ +static void wait_tconvert() { + + printf("Info: Converting temp\n"); + /* initiate write slot */ out_conf(); rclrbit(GPIOB_ODR, 6); _block(3); in_conf(); while (!rchkbit(GPIOB_IDR, 6)) { - printf("c"); + //printf("."); _block(60); out_conf(); rclrbit(GPIOB_ODR, 6); @@ -382,74 +157,77 @@ void wait_for_sensor() { } } -void run() { +/* Print some serial and CRC information about the chip */ +void tsensor_printid() { + + tsensor_init(); + send_cmd(READ_ROM); + + // replies with 8 bytes + int nbytes = 8; - cnt = 0; -//w2 rsetbit(RCC_APB2ENR, 3); -//w2 rwrite(GPIOB_CRL, 0x48444444); // input with pull up down -//w2 tsensor_simple(5000); + char scratchbuf[nbytes]; + memset(&scratchbuf, 0, sizeof(char) * nbytes); + scratchbuf[nbytes+1] = '\n'; + + for (int i = 0; i < nbytes; i++) { + scratchbuf[i] = get_byte(); + } + + + printf("Family Code: %#x\n", scratchbuf[0]); + printf("Serial Number: 0x"); + for (int i = 1; i < 7; i++) { + printf("%x", scratchbuf[i]); + } + printf("\n"); + printf("CRC Code: %#x\n", scratchbuf[7]); + +} - //cnt = 0; - //rsetbit(RCC_APB2ENR, 3); // GPIOB enable - //rwrite(GPIOB_CRL, 0x46444444); // open drain general for sensor? +/* Convert and read temperature of chip. Sensor has to be initialized twice + * since there are two series of commands (see datasheet flowchart) */ +uint16_t tsensor_get_temp() { - //rsetbit(GPIOB_BSRR, 22); // low (<- reset) + /* initialize sensor and send commands */ + tsensor_init(); + send_cmd(SKIP_ROM); + send_cmd(CONVERT_T); + wait_tconvert(); tsensor_init(); - send_cmd(0xCC); - send_cmd(0x44); - wait_for_sensor(); + send_cmd(SKIP_ROM); + send_cmd(READ_SCRATCH); - tsensor_init(); - send_cmd(0xCC); - send_cmd(0xBE); + /* Scratchpad is 9 bytes, but we are only interested in + * the first two bytes, since they contain the LSB and + * MSB of temperature */ + int nbytes = 2; + + char scratchbuf[nbytes]; + memset(&scratchbuf, 0, sizeof(char) * nbytes); + scratchbuf[nbytes+1] = '\n'; + + for (int i = 0; i < nbytes; i++) { + scratchbuf[i] = get_byte(); + } + + // LSB first four bits are after floating point + // uint8_t lsb_afltp = scratchbuf[0] & 0xF; + + int8_t lsb_bfltp = (scratchbuf[0] >> 4) & 0xF; + // MSB only the first three bits are used + uint8_t msb = scratchbuf[1] & 0x7; + + return (msb << 4) + lsb_bfltp; - //send_cmd(0xCC); - //send_cmd(0x44); - //wait_for_sensor(); - //send_cmd(0xBE); - //wait_for_sensor(); - read_reply(); - //send_cmd(0x33); - //read_reply(); -// write_init(); - -// tsensor_output(580, 520); -// reset(); -// tsensor_simple(580); } -//void tsensor_output(uint16_t preload, uint16_t compare/*, uint16_t pulses */) { -// /* GPIO AND CLOCK */ -// rsetbit(RCC_APB2ENR, 3); // GPIOB enable -// rwrite(GPIOB_CRL, 0x4A444444); // PB6 for Channel 1 TIM4 alternate -// rsetbit(RCC_APB1ENR, 2); // TIM4 enable -// -// rsetbitsfrom(TIM4_CR1, 5, 0x00); // edge-aligned mode -// rclrbit(TIM4_CR1, 4); // upcounter (clrbit! not needed to set) -// rsetbit(TIM4_CR1, 2); // only overflow generates update -// -// rwrite(TIM4_PSC, PRESCALER - 1); // 1 MHz -// rwrite(TIM4_ARR, preload); // preload -// rwrite(TIM4_CCR1, compare); // compare -// //rwrite(TIM4_RCR, pulses - 1); /* repeat ONLY IN ADVANCED TIMER */ -// -// rsetbit(TIM4_EGR, 0); // update generation -// -// rsetbit(TIM4_CR1, 3); // one pulse mode -// rsetbitsfrom(TIM4_CCMR1, 4, 0x6); // mode -// -// //rsetbit(TIM4_CCMR1, 3); // preload enable -// //rsetbit(TIM4_CR1, 7); // buffered -// -// rsetbit(TIM4_CCER, 0); // enable output channeli 1 -// rsetbit(TIM4_CCER, 1); // active low -// rsetbit(TIM4_CR1, 0); // start counter -// -// /* INTERRUPTS */ -// ivt_set_gate(46, tmp_update_handler, 0); -// -// rsetbit(TIM4_DIER, 1); -// rsetbit(NVIC_ISER0, 30); // interupt 41 - 32 -// -//} +/* +void test() { + + //get_id(); + uint16_t temp = get_temp(); + printf("Current temperature: %d\n", temp); + +} */ diff --git a/include/drivers/tsensor.h b/include/drivers/tsensor.h index ced6f5d..9695eb7 100644 --- a/include/drivers/tsensor.h +++ b/include/drivers/tsensor.h @@ -1,4 +1,8 @@ -extern void tsensor_output(uint16_t, uint16_t/* , uint16_t */); -extern void tsensor_input(uint16_t); -extern void run(); +#ifndef __TSENSOR_H +#define __TSENSOR_H + +extern void tsensor_printid(); +extern uint16_t tsensor_get_temp(); + +#endif diff --git a/main.c b/main.c index 3c1035b..d2087d7 100644 --- a/main.c +++ b/main.c @@ -68,7 +68,9 @@ void main() // _block(10000); /* TEMP SENSOR */ - run(); + tsensor_printid(); + uint16_t temp = tsensor_get_temp(); + printf("Current temperature: %d °C\n", temp); /* Start up terminal */ terminal(); -- 2.7.4