sample code for PCF8573 RTC Chip

2 files changed, 177 insertions, 0 deletions

diff --git a/usb-pcf8573/Makefile b/usb-pcf8573/Makefile
new file mode 100644
index 0000000..a294a2b
--- /dev/null
+++ b/usb-pcf8573/Makefile
@@ -0,0 +1,47 @@
+##
+##  spreadspace avr utils
+##
+##
+##  Copyright (C) 2013-2018 Christian Pointner <equinox@spreadspace.org>
+##
+##  This file is part of spreadspace avr utils.
+##
+##  spreadspace avr utils is free software: you can redistribute it and/or modify
+##  it under the terms of the GNU General Public License as published by
+##  the Free Software Foundation, either version 3 of the License, or
+##  any later version.
+##
+##  spreadspace avr utils 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 spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+##
+
+NAME := usb-pcf8573
+BOARD_TYPE := teensy2
+OBJ := $(NAME).o
+LIBS := util led lufa-descriptor-usbserial usbio
+EXTERNAL_LIBS := lufa
+SPREADAVR_PATH := ../contrib/avr-utils
+RESET_FUNC := $(SPREADAVR_PATH)/tools/reset_lufa_cdc
+RESET_PARAM := 'r'
+
+LUFA_PATH := $(SPREADAVR_PATH)/contrib/lufa-LUFA-151115
+LUFA_OPTS  = -D USB_DEVICE_ONLY
+LUFA_OPTS += -D DEVICE_STATE_AS_GPIOR=0
+LUFA_OPTS += -D ORDERED_EP_CONFIG
+LUFA_OPTS += -D FIXED_CONTROL_ENDPOINT_SIZE=8
+LUFA_OPTS += -D FIXED_NUM_CONFIGURATIONS=1
+LUFA_OPTS += -D USE_FLASH_DESCRIPTORS
+LUFA_OPTS += -D USE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+LUFA_OPTS += -D INTERRUPT_CONTROL_ENDPOINT
+
+LUFA_OPTS += -D USB_MANUFACTURER="L\"equinox\""
+LUFA_OPTS += -D USB_PRODUCT="L\"spreadspace usb-pcf8573\""
+
+LUFA_COMPONENTS := USB USBCLASS TWI
+
+include $(SPREADAVR_PATH)/include.mk
diff --git a/usb-pcf8573/usb-pcf8573.c b/usb-pcf8573/usb-pcf8573.c
new file mode 100644
index 0000000..86ed618
--- /dev/null
+++ b/usb-pcf8573/usb-pcf8573.c
@@ -0,0 +1,130 @@
+/*
+ *  spreadspace avr utils
+ *
+ *
+ *  Copyright (C) 2013-2019 Christian Pointner <equinox@spreadspace.org>
+ *
+ *  This file is part of spreadspace avr utils.
+ *
+ *  spreadspace avr utils is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  spreadspace avr utils 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 spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <avr/interrupt.h>
+#include <avr/power.h>
+#include <stdio.h>
+
+#include "util.h"
+#include "led.h"
+#include "usbio.h"
+
+#include <LUFA/Drivers/Peripheral/TWI.h>
+
+#define RTC_SLAVE_ADDR 0xD0
+
+char* i2c_error_to_string(uint8_t err) {
+  switch(err) {
+  case TWI_ERROR_NoError: return "success";
+  case TWI_ERROR_BusFault: return "bus-fault";
+  case TWI_ERROR_BusCaptureTimeout: return "bus capture timeout";
+  case TWI_ERROR_SlaveResponseTimeout: return "slave response timeout";
+  case TWI_ERROR_SlaveNotReady: return "slave not ready";
+  case TWI_ERROR_SlaveNAK: return "slave NAK";
+  }
+  return "unknown";
+}
+
+void i2c_init(void)
+{
+  TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 100000));
+}
+
+void get_time(void)
+{
+  uint8_t err = TWI_StartTransmission(RTC_SLAVE_ADDR | TWI_ADDRESS_WRITE, 100);
+  if(err != TWI_ERROR_NoError) {
+    printf("I²C start failed: %s\r\n", i2c_error_to_string(err));
+    return;
+  }
+
+  err = TWI_SendByte(0x00);
+  if(err != TWI_ERROR_NoError)
+    goto i2c_error;
+
+  err = TWI_StartTransmission(RTC_SLAVE_ADDR | TWI_ADDRESS_READ, 10);
+  if(err != TWI_ERROR_NoError)
+    goto i2c_error;
+
+  uint8_t time[4];
+  for(int i = 0; i < sizeof(time); ++i) {
+    time[i] = 0xFF;
+    err = TWI_ReceiveByte(&(time[i]), (i+1 == sizeof(time)) ? true : false);
+    if(err != TWI_ERROR_NoError)
+      goto i2c_error;
+  }
+  TWI_StopTransmission();
+
+  for(int i = 0; i < sizeof(time); ++i) {
+    printf("%s0x%02X%s", ((i==0) ? "" : " "), time[i], (i+1 == sizeof(time)) ? "\r\n" : "");
+  }
+  return;
+
+i2c_error:
+  TWI_StopTransmission();
+  printf("I2C error: %s\r\n", i2c_error_to_string(err));
+  return;
+}
+
+
+void handle_cmd(uint8_t cmd)
+{
+  switch(cmd) {
+  case '0': led_off(); printf("ok\r\n"); break;
+  case '1': led_on(); printf("ok\r\n"); break;
+  case 't': get_time(); break;
+  case 'r': reset2bootloader(); break;
+  default: printf("error\r\n"); return;
+  }
+
+}
+
+int main(void)
+{
+  MCUSR &= ~(1 << WDRF);
+  wdt_disable();
+
+  cpu_init();
+  jtag_disable();
+
+  led_init();
+  usbio_init();
+  i2c_init();
+  sei();
+
+  led_on();
+  for(;;) {
+    int16_t BytesReceived = usbio_bytes_received();
+    while(BytesReceived > 0) {
+      int ReceivedByte = fgetc(stdin);
+      if(ReceivedByte != EOF) {
+        handle_cmd(ReceivedByte);
+      }
+      BytesReceived--;
+    }
+
+    usbio_task();
+  }
+}