Implement EEPROM and use it for saving the calibration

stm-firmware/Makefile

@@ -45,7 +45,7 @@ CFILES += rotary-encoder.c button.c
 CFILES += ui/lcd.c ui/menu.c ui/gui.c
 CFILES += fatfs/diskio.c fatfs/ff.c fatfs/ffsystem.c fatfs/ffunicode.c fatfs/shimatta_sdio_driver/shimatta_sdio.c
 CFILES += pid-controller.c oven-driver.c
-CFILES += settings/settings.c settings/settings-sd-card.c settings/spi-eeprom.c
+CFILES += settings/settings.c settings/settings-sd-card.c settings/spi-eeprom.c settings/settings-eeprom.c
 CFILES += stm-periph/crc-unit.c
 CFILES += safety/safety-adc.c safety/safety-controller.c safety/watchdog.c safety/fault.c safety/safety-memory.c safety/stack-check.c
 CFILES += hw-version-detect.c

stm-firmware/include/reflow-controller/settings/settings-eeprom.h

@@ -0,0 +1,32 @@
+/* Reflow Oven Controller
+*
+* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
+*
+* This file is part of the Reflow Oven Controller Project.
+*
+* The reflow oven controller is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License version 2 as
+* published by the Free Software Foundation.
+*
+* The Reflow Oven Control Firmware 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 General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with the reflow oven controller project.
+* If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __SETTINGS_SETTINGS_EEPROM_H__
+#define __SETTINGS_SETTINGS_EEPROM_H__
+
+#include <stdbool.h>
+
+bool settings_eeprom_detect_and_prepare(void);
+
+int settings_eeprom_save_calibration(float sens, float offset, bool active);
+
+int settings_eeprom_load_calibration(float *sens, float *offset, bool *active);
+
+#endif /* __SETTINGS_SETTINGS_EEPROM_H__ */

stm-firmware/include/reflow-controller/settings/settings.h

@@ -53,4 +53,6 @@ int settings_load_calibration(float *sens_dev, float *offset);
 
 enum settings_load_result settings_load_pid_oven_parameters(struct oven_pid_settings *settings);
 
+void settings_setup(void);
+
 #endif /* __SETTINGS_SETTINGS_H__ */

stm-firmware/include/reflow-controller/settings/spi-eeprom.h

@@ -22,6 +22,8 @@
 #define __SETTINGS_SPI_EEPROM_H__
 
 #include <stdint.h>
+#include <stdbool.h>
+
 
 int spi_eeprom_init();
 
@@ -29,8 +31,12 @@ void spi_eeprom_deinit();
 
 int spi_eeprom_read(uint32_t addr, uint8_t *rx_buff, uint32_t count);
 
+bool spi_eeprom_write_in_progress(void);
+
 int spi_eeprom_write(uint32_t addr, const uint8_t *data, uint32_t count);
 
 uint8_t spi_eeprom_read_status_reg(void);
 
+bool spi_eeprom_check_connected(void);
+
 #endif /* __SETTINGS_SPI_EEPROM_H__ */

stm-firmware/main.c

@@ -46,6 +46,7 @@
 #include <reflow-controller/safety/safety-memory.h>
 #include <reflow-controller/safety/fault.h>
 #include <reflow-controller/updater/updater.h>
+
 #include <reflow-controller/settings/spi-eeprom.h>
 
 static void setup_nvic_priorities(void)
@@ -179,7 +180,7 @@ static inline void setup_system(void)
 	loudspeaker_setup();
 	gui_init();
 	uart_gpio_config();
-	spi_eeprom_init();
+	settings_setup();
 
 	handle_boot_status();
 
@@ -210,8 +211,15 @@ int main(void)
 	shellmatta_handle_t shell_handle;
 	int menu_wait_request;
 	uint64_t quarter_sec_timestamp = 0ULL;
+
 	setup_system();
 
+	/* Try load the calibration. This will only succeed if there's an EEPROM */
+	status = settings_load_calibration(&sens, &offset);
+	if (!status) {
+		adc_pt1000_set_resistance_calibration(offset, sens, true);
+	}
+
 	shell_handle = shell_init(write_shell_callback);
 	shell_print_motd(shell_handle);
 

stm-firmware/settings/settings-eeprom.c

@@ -0,0 +1,140 @@
+/* Reflow Oven Controller
+*
+* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
+*
+* This file is part of the Reflow Oven Controller Project.
+*
+* The reflow oven controller is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License version 2 as
+* published by the Free Software Foundation.
+*
+* The Reflow Oven Control Firmware 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 General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with the reflow oven controller project.
+* If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <reflow-controller/settings/settings-eeprom.h>
+#include <reflow-controller/settings/spi-eeprom.h>
+#include <stm-periph/crc-unit.h>
+#include <string.h>
+
+#define EEPROM_HEADER_MAGIC 0xA5
+#define EEPROM_HEADER_COMP_VER 0xFF
+
+static const uint8_t expected_header[2] = {EEPROM_HEADER_MAGIC, EEPROM_HEADER_COMP_VER};
+
+#define EEPROM_CALIBRATION_BASE_ADDR 0x2
+struct eeprom_calibration_settings {
+	uint32_t active;
+	float offset;
+	float sens_dev;
+	uint32_t crc;
+};
+
+static bool check_eeprom_header(void)
+{
+	uint8_t header[2] = {0};
+
+	/* Try to read the magic header and the compatible version */
+	spi_eeprom_read(0x0, header, 2);
+	if (memcmp(header, expected_header, 2))
+		return false;
+	else
+		return true;
+}
+
+static void settings_eeprom_zero()
+{
+	settings_eeprom_save_calibration(0.0f, 0.0f, false);
+}
+
+bool settings_eeprom_detect_and_prepare(void)
+{
+	bool eeprom_ready = false;;
+
+	int res;
+
+	crc_unit_init();
+	res = spi_eeprom_init();
+	if (res)
+		goto ret_deinit_crc;
+
+	if (!spi_eeprom_check_connected())
+		goto ret_deinit_crc;
+
+	if (check_eeprom_header() == false) {
+		/* Try to write a new header and check it again */
+		spi_eeprom_write(0, expected_header, sizeof(expected_header));
+		while (spi_eeprom_write_in_progress());
+		if (check_eeprom_header() == false) {
+			goto ret_deinit_crc;
+		} else {
+			/* Sucessfully written new header
+			 * Zero out the rest of the settings
+			 */
+			settings_eeprom_zero();
+			eeprom_ready = true;
+		}
+	} else {
+		eeprom_ready = true;
+	}
+
+	goto exit;
+
+ret_deinit_crc:
+	crc_unit_deinit();
+
+exit:
+	return eeprom_ready;
+}
+
+int settings_eeprom_save_calibration(float sens, float offset, bool active)
+{
+	int res;
+
+	struct eeprom_calibration_settings sett;
+
+	sett.active = (active ? 0xAABBCCDD : 0);
+	sett.offset = offset;
+	sett.sens_dev = sens;
+
+	crc_unit_reset();
+	crc_unit_input_array((const uint32_t *)&sett, (sizeof(sett) / 4)-1);
+	sett.crc = crc_unit_get_crc();
+
+	res = spi_eeprom_write(EEPROM_CALIBRATION_BASE_ADDR, (uint8_t *)&sett, sizeof(sett));
+
+	if (res)
+		return -2;
+	else
+		return 0;
+}
+
+int settings_eeprom_load_calibration(float *sens, float *offset, bool *active)
+{
+	struct eeprom_calibration_settings sett;
+	int res;
+
+	res = spi_eeprom_read(EEPROM_CALIBRATION_BASE_ADDR, (uint8_t *)&sett, sizeof(sett));
+	if (res)
+		return -2;
+
+	crc_unit_reset();
+	crc_unit_input_array((const uint32_t *)&sett, sizeof(sett) / 4 - 1);
+	if (crc_unit_get_crc() == sett.crc) {
+		if (sens)
+			*sens = sett.sens_dev;
+		if (offset)
+			*offset = sett.offset;
+		if (active)
+			*active = (sett.active ? true : false);
+		return 0;
+	} else {
+		return -1;
+	}
+}

stm-firmware/settings/settings.c

@@ -20,19 +20,47 @@
 
 #include <reflow-controller/settings/settings.h>
 #include <reflow-controller/settings/settings-sd-card.h>
+#include <reflow-controller/settings/settings-eeprom.h>
+#include <reflow-controller/hw-version-detect.h>
+
+bool settings_use_eeprom;
 
 int settings_save_calibration(float sens_deviation, float offset, bool active)
 {
-	/* There is no other configuration location besides the SD card (yet) */
+	if (settings_use_eeprom)
+		return settings_eeprom_save_calibration(sens_deviation, offset, active);
+	else
 		return sd_card_settings_save_calibration(sens_deviation, offset, active);
 }
 
 int settings_load_calibration(float *sens_dev, float *offset)
 {
-	return sd_card_settings_try_load_calibration(sens_dev, offset);
+	bool active;
+	int res;
+
+	if (settings_use_eeprom) {
+		res =settings_eeprom_load_calibration(sens_dev, offset, &active);
+		if (!res && !active)
+			res = -1;
+	} else  {
+		res = -1;
+	}
+
+	if (res)
+		res = sd_card_settings_try_load_calibration(sens_dev, offset);
+
+	return res;
 }
 
 enum settings_load_result settings_load_pid_oven_parameters(struct oven_pid_settings *settings)
 {
 	return sd_card_settings_load_pid_oven_parameters(settings);
 }
+
+void settings_setup(void)
+{
+	if (get_pcb_hardware_version() >= HW_REV_V1_3)
+		settings_use_eeprom = settings_eeprom_detect_and_prepare();
+	else
+		settings_use_eeprom = false;
+}

stm-firmware/settings/spi-eeprom.c

@@ -23,10 +23,23 @@
 #include <reflow-controller/periph-config/spi-eeprom-hwcfg.h>
 #include <stm-periph/rcc-manager.h>
 #include <stm-periph/stm32-gpio-macros.h>
+#include <stddef.h>
 
 #define EEPROM_SIZE 0x200
 #define EEPROM_PAGE_SIZE 16
 
+#define EEPROM_STATUS_REG_WIP (0x1U)
+#define EEPROM_STATUS_REG_WEL (0x1U << 1)
+#define EEPROM_STATUS_REG_BP0 (0x1U << 2)
+#define EEPROM_STATUS_REG_BP1 (0x1U << 3)
+
+#define EEPROM_CMD_READ_STATUS 0x05
+#define EEPROM_CMD_WRITE_STATUS 0x01
+#define EEPROM_CMD_READ_DATA 0x3
+#define EEPROM_CMD_WRITE_DATA 0x2
+#define EEPROM_CMD_WREN 0x6
+#define EEPROM_CMD_WRDI 0x4
+
 static stm_spi_handle eeprom_spi_handle;
 
 static void eeprom_cs_activate(void)
@@ -63,7 +76,7 @@ int spi_eeprom_init()
 	settings.cs_deactivate = eeprom_cs_deactivate;
 	settings.master = true;
 	settings.msb_first = true;
-	settings.prescaler = SPI_PRSC_DIV64;
+	settings.prescaler = SPI_PRSC_DIV16;
 	eeprom_spi_handle = spi_init(&spi_dev, SPI1, &settings);
 
 	if (eeprom_spi_handle)
@@ -91,9 +104,24 @@ uint8_t spi_eeprom_read_status_reg(void)
 	return buff[1];
 }
 
+static void spi_eeprom_set_write_enable_latch(bool status)
+{
+	uint8_t cmd;
+
+	if (status)
+		cmd = EEPROM_CMD_WREN;
+	else
+		cmd = EEPROM_CMD_WRDI;
+
+	(void)spi_transfer(eeprom_spi_handle, &cmd, NULL, 1, true);
+}
+
 int spi_eeprom_read(uint32_t addr, uint8_t *rx_buff, uint32_t count)
 {
 	int ret = 0;
+	int retry = 250;
+	uint8_t status_reg;
+	uint8_t cmd[2];
 
 	if (!rx_buff || !count)
 		return -1000;
@@ -101,15 +129,100 @@ int spi_eeprom_read(uint32_t addr, uint8_t *rx_buff, uint32_t count)
 	if (addr >= EEPROM_SIZE)
 		return -1001;
 
+	do {
+		status_reg = spi_eeprom_read_status_reg();
+	} while ((status_reg & EEPROM_STATUS_REG_WIP) && retry--);
 
+	if (status_reg & EEPROM_STATUS_REG_WIP)
+		return -1;
+
+	cmd[0] = EEPROM_CMD_READ_DATA;
+	if (addr & (1<<8))
+		cmd[0] |= (1U<<3);
+	cmd[1] = (uint8_t)(addr & 0xFF);
 
 	eeprom_cs_activate();
-
+	spi_transfer(eeprom_spi_handle, cmd, NULL, 2, false);
-
+	spi_transfer(eeprom_spi_handle, NULL, rx_buff, count, false);
-
 	eeprom_cs_deactivate();
 
 	return ret;
 }
 
-int spi_eeprom_write(uint32_t addr, const uint8_t *data, uint32_t count);
+bool spi_eeprom_write_in_progress(void)
+{
+	uint8_t status_reg;
+
+	status_reg = spi_eeprom_read_status_reg();
+
+	if (status_reg & EEPROM_STATUS_REG_WIP)
+		return true;
+	else
+		return false;
+}
+
+static void spi_eeprom_do_write_page(uint32_t addr, const uint8_t *data, uint8_t len)
+{
+	uint8_t cmd[2];
+
+	/* Wait for the previous write to finish */
+	while (spi_eeprom_write_in_progress());
+	/* Set the write enable latch */
+	spi_eeprom_set_write_enable_latch(true);
+
+	cmd[0] = EEPROM_CMD_WRITE_DATA | ((addr & (1<<8)) ? (1<<4) : 0);
+	cmd[1] = (uint8_t)(addr & 0xFF);
+
+	eeprom_cs_activate();
+	spi_transfer(eeprom_spi_handle, cmd, NULL, 2, false);
+	spi_transfer(eeprom_spi_handle, data, NULL, len, false);
+	eeprom_cs_deactivate();
+}
+
+int spi_eeprom_write(uint32_t addr, const uint8_t *data, uint32_t count)
+{
+	const uint8_t *ptr = data;
+	uint32_t transfer_len;
+
+	if (!data || !count)
+		return -1000;
+
+	if (addr >= EEPROM_SIZE)
+		return -1001;
+
+	while (count > 0) {
+		/* Calculate size for current page transfer */
+		transfer_len = EEPROM_PAGE_SIZE - (addr % EEPROM_PAGE_SIZE);
+		if (transfer_len > count)
+			transfer_len = count;
+
+		spi_eeprom_do_write_page(addr, ptr, transfer_len);
+		count -= transfer_len;
+		addr += transfer_len;
+		ptr += transfer_len;
+	}
+
+	return 0;
+}
+
+bool spi_eeprom_check_connected(void)
+{
+	uint8_t status_reg;
+
+	/* Try to set write enable latch */
+	spi_eeprom_set_write_enable_latch(true);
+
+	/* Read back status register */
+	status_reg = spi_eeprom_read_status_reg();
+	if (!(status_reg & EEPROM_STATUS_REG_WEL))
+		return false;
+
+	/* Clear the latch */
+	spi_eeprom_set_write_enable_latch(false);
+	/* Read back status register */
+	status_reg = spi_eeprom_read_status_reg();
+	if ((status_reg & EEPROM_STATUS_REG_WEL))
+		return false;
+
+	return true;
+}