void display_init(void)
{
SPI_set_sample_rising_edge();
/* Disable shutdown mode */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_SHUTDOWN);
SPI_send(0x1);
SPI_deselect(SPI_CS_MAX7221);
/* Disable display test mode */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DISPLAY_TEST);
SPI_send(0x0);
SPI_deselect(SPI_CS_MAX7221);
/* Set the decoding mode to Code-B font for all digits */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DECODE_MODE);
SPI_send(0xFF);
SPI_deselect(SPI_CS_MAX7221);
/* Set the display intensity */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_INTENSITY);
SPI_send(0xF);
SPI_deselect(SPI_CS_MAX7221);
/* Set the scan limit to include all 8 digits */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_SCAN_LIMIT);
SPI_send(0x07);
SPI_deselect(SPI_CS_MAX7221);
}
/**
Transforms the humidity value given in percent relative humidity into
decimal digits and sends the information to the 7-segment display controller.
The display is updated when the chip select signal is deactivated.
\param humidity Integer that represents relative humidity in percent.
*/
void display_humidity(uint8_t humidity)
{
SPI_set_sample_rising_edge();
/* Values of each of the 3 digits */
uint8_t digit [3];
/* Determine the value of each digit */
int8_t tmp;
tmp = humidity / 10;
digit[2] = humidity - 10 * tmp;
humidity = tmp;
tmp = humidity / 10;
digit[1] = humidity - 10 * tmp;
humidity = tmp;
tmp = humidity / 10;
digit[0] = humidity - 10 * tmp;
/* Eliminate leading zeros */
if (digit[0] == 0) {
digit[0] = DISPLAY_CODE_B_BLANK;
if (digit[1] == 0) {
digit[1] = DISPLAY_CODE_B_BLANK;
}
}
/* Send the SPI commands */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_5);
SPI_send(digit[0]);
SPI_deselect(SPI_CS_MAX7221);
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_6);
SPI_send(digit[1]);
SPI_deselect(SPI_CS_MAX7221);
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_7);
SPI_send(digit[2]);
SPI_deselect(SPI_CS_MAX7221);
}
void SPI_select(int dev)
{
SPI_deselect();
switch(dev) {
case MEMCS:
ClearPin(PORTB, MEM_SEL);
break;
case VSXCS:
ClearPin(PORTD, VS_XCS);
break;
case VSXDCS:
ClearPin(PORTD, VS_XDCS);
break;
}
}
// Initializes mem card
char MEM_init()
{
char val;
mem_bus_granted = 0;
// acquire the SPI bus and other necesary signals
val = MEM_acquireControl();
if(val)
return(val);
// reset to known idle state
// assert reset, wait and deassert reset
ClearPin(PORTC, MEM_RESET);
delay(1);
SetPin(PORTC, MEM_RESET);
// get memory status
// select memory
SPI_select(MEMCS);
// read status register
SPI_send(READ_STATUS_REGISTER);
// get return value
val = SPI_receive(0x00);
SPI_deselect();
if(((val >> 2) & 0x0f) == 0x0f) {
if(!(val & 0x01)) {
MEM.mem_size = 8650752;
MEM.page_size = 1056;
}
else {
blinkLED(10);
}
MEM.fbell_offset = MEM.page_size;
MEM.rbell_offset = MEM.mem_size / 2;
}
else
/**
Transforms the given temperature that is represented as degrees Celsius
times 100 into decimal digits in preparation for display.
Then it transfers the information to the 7-segment display controller.
The display is updated as soon as the chip select signal is deactivated.
\param temperature Integer that represents temperature in Celsius multiplied by the factor 100.
*/
void display_temperature(int16_t temperature)
{
SPI_set_sample_rising_edge();
/* Values of each of the 5 digits */
uint8_t digit [5];
/* Test for negativity */
if (temperature < 0) {
temperature = -temperature;
digit[0] = DISPLAY_CODE_B_MINUS;
} else {
digit[0] = DISPLAY_CODE_B_BLANK;
}
/* Determine the value of each digit */
int16_t tmp;
tmp = temperature / 10;
digit[4] = temperature - 10 * tmp;
temperature = tmp;
tmp = temperature / 10;
digit[3] = temperature - 10 * tmp;
temperature = tmp;
tmp = temperature / 10;
digit[2] = temperature - 10 * tmp;
digit[2] |= DISPLAY_CODE_DECIMAL_POINT;
temperature = tmp;
tmp = temperature / 10;
digit[1] = temperature - 10 * tmp;
/* Eliminate leading zeros */
if (digit[1] == 0) {
/* The 0th digit may contain a minus sign */
digit[1] = digit[0];
digit[0] = DISPLAY_CODE_B_BLANK;
}
/* Send the SPI commands for digit 0 */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_0);
SPI_send(digit[0]);
SPI_deselect(SPI_CS_MAX7221);
/* Send the SPI commands for digit 1 */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_1);
SPI_send(digit[1]);
SPI_deselect(SPI_CS_MAX7221);
/* Send the SPI commands for digit 2 */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_2);
SPI_send(digit[2]);
SPI_deselect(SPI_CS_MAX7221);
/* Send the SPI commands for digit 3 */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_3);
SPI_send(digit[3]);
SPI_deselect(SPI_CS_MAX7221);
/* Send the SPI commands for digit 4 */
SPI_select(SPI_CS_MAX7221);
SPI_send(DISPLAY_REG_DIGIT_4);
SPI_send(digit[4]);
SPI_deselect(SPI_CS_MAX7221);
}
