+/*********************************************
+* vim: set sw=8 ts=8 si et :
+* Author: Guido Socher, Copyright: GPL v3
+* This is the main program for the digital dc power supply
+*
+* See http://www.tuxgraphics.org/electronics/
+*
+* Chip type : ATMEGA8
+* Clock frequency : Internal clock 8 Mhz
+*********************************************/
+#include <avr/io.h>
+#include <inttypes.h>
+#include <avr/interrupt.h>
+#define F_CPU 8000000UL // 8 MHz
+#include <util/delay.h>
+#include <stdlib.h>
+#include <string.h>
+#include <avr/eeprom.h>
+#include "lcd.h"
+#include "dac.h"
+#include "kbd.h"
+#include "uart.h"
+#include "analog.h"
+#include "hardware_settings.h"
+
+// change this version string when you compile:
+#define SWVERSION "ver: ddcp-0.6.3"
+//#define DEBUGDISP 1
+
+//debug LED:
+// set output to VCC, red LED off
+#define LEDOFF PORTD|=(1<<PORTD0)
+// set output to GND, red LED on
+#define LEDON PORTD&=~(1<<PORTD0)
+// to test the state of the LED
+#define LEDISOFF PORTD&(1<<PORTD0)
+//
+// the units are display units and work as follows: 100mA=10 5V=50
+// The function int_to_dispstr is used to convert the intenal values
+// into strings for the display
+static int16_t measured_val[2]={0,0};
+static int16_t set_val[2];
+// the set values but converted to ADC steps
+static int16_t set_val_adcUnits[2];
+static uint8_t bpress=0;
+// comment this out to use a debug LED on PD0 (RXD):
+#define USE_UART 1
+//
+#ifdef USE_UART
+#define UARTSTRLEN 10
+static char uartstr[UARTSTRLEN+1];
+static uint8_t uartstrpos=0;
+static uint8_t uart_has_one_line=0;
+#endif
+
+void delay_ms_uartcheck(uint8_t ms)
+// delay for a minimum of <ms>
+{
+ uint8_t innerloop=1;
+ while(ms){
+#ifdef USE_UART
+ if(uart_has_one_line==0 && uart_getchar_isr_noblock(&uartstr[uartstrpos])){
+ // ignore any white space:
+ if (uartstr[uartstrpos]==' ' || uartstr[uartstrpos]=='\t'){
+ goto NEXTCHAR;
+ }
+ if (uartstr[uartstrpos]=='\r'){
+ uartstr[uartstrpos]='\0';
+ uart_sendchar('\r'); // the echo line end
+ uart_sendchar('\n'); // the echo line end
+ //uart_sendchar('|'); uart_sendstr(&uartstr[0]);uart_sendchar('|'); //debug
+ uart_has_one_line=1;
+ goto NEXTCHAR;
+ }
+ uart_sendchar(uartstr[uartstrpos]);// echo back
+ /*
+ // debug
+ itoa(uartstr[uartstrpos],buf,10);
+ uart_sendchar('\r'); // the echo line end
+ uart_sendchar('\n'); // the echo line end
+ uart_sendstr(buf);
+ uart_sendchar('\r'); // the echo line end
+ uart_sendchar('\n'); // the echo line end
+ */
+ if (uartstr[uartstrpos]=='\b'){
+ if (uartstrpos>0){
+ uartstrpos--;
+ uart_sendchar(' '); // clear char on screen
+ uart_sendchar('\b');
+ }
+ }else if (uartstr[uartstrpos]==0x7f){ // del
+ if (uartstrpos>0){
+ uartstrpos--;
+ }
+ }else{
+ uartstrpos++;
+ }
+ if (uartstrpos>UARTSTRLEN){
+ uart_sendstr_P("\r\nERROR\r\n");
+ uartstrpos=0; // empty buffer
+ uartstr[0]='\0'; // just print prompt
+ uart_has_one_line=1;
+ }
+ }
+#endif
+NEXTCHAR:
+ innerloop--;
+ if (innerloop==0){
+ innerloop=45;
+ ms--;
+ }
+ }
+}
+
+// Convert an integer which is representing a float into a string.
+// Our display is always 4 digits long (including one
+// decimal point position). decimalpoint_pos defines
+// after how many positions from the right we set the decimal point.
+// The resulting string is fixed width and padded with leading space.
+//
+// decimalpoint_pos=2 sets the decimal point after 2 pos from the right:
+// e.g 74 becomes "0.74"
+// The integer should not be larger than 999.
+// The integer must be a positive number.
+// decimalpoint_pos can be 0, 1 or 2
+static void int_to_dispstr(uint16_t inum,char *outbuf,int8_t decimalpoint_pos){
+ int8_t i,j;
+ char chbuf[8];
+ itoa(inum,chbuf,10); // convert integer to string
+ i=strlen(chbuf);
+ if (i>3) i=3; //overflow protection
+ strcpy(outbuf," 0"); //decimalpoint_pos==0
+ if (decimalpoint_pos==1) strcpy(outbuf," 0.0");
+ if (decimalpoint_pos==2) strcpy(outbuf,"0.00");
+ j=4;
+ while(i){
+ outbuf[j-1]=chbuf[i-1];
+ i--;
+ j--;
+ if (j==4-decimalpoint_pos){
+ // jump over the pre-set dot
+ j--;
+ }
+ }
+}
+
+// convert voltage values to adc values, disp=10 is 1.0V
+// ADC for voltage is 11bit:
+static int16_t disp_u_to_adc(int16_t disp){
+ return((int16_t)(((float)disp * 204.7) / (ADC_REF * U_DIVIDER )));
+}
+// calculate the needed adc offset for voltage drop on the
+// current measurement shunt (the shunt has about 0.75 Ohm =1/1.33 Ohm)
+// use 1/1.2 instead of 1/1.3 because cables and connectors have as well
+// a loss.
+static int16_t disp_i_to_u_adc_offset(int16_t disp){
+ return(disp_u_to_adc(disp/12));
+}
+// convert adc values to voltage values, disp=10 is 1.0V
+// disp_i_val is needed to calculate the offset for the voltage drop over
+// the current measurement shunt, voltage measurement is 11bit
+static int16_t adc_u_to_disp(int16_t adcunits,int16_t disp_i_val){
+ int16_t adcdrop;
+ adcdrop=disp_i_to_u_adc_offset(disp_i_val);
+ if (adcunits < adcdrop){
+ return(0);
+ }
+ adcunits=adcunits-adcdrop;
+ return((int16_t)((((float)adcunits /204.7)* ADC_REF * U_DIVIDER)+0.5));
+}
+// convert adc values to current values, disp=10 needed to be printed
+// by the printing function as 0.10 A, current measurement is 10bit
+static int16_t disp_i_to_adc(int16_t disp){
+ return((int16_t) (((disp * 10.23)* I_RESISTOR) / ADC_REF));
+}
+// convert adc values to current values, disp=10 needed to be printed
+// by the printing function as 0.10 A, current measurement is 10bit
+static int16_t adc_i_to_disp(int16_t adcunits){
+ return((int16_t) (((float)adcunits* ADC_REF)/(10.23 * I_RESISTOR)+0.5));
+}
+
+static void store_permanent(void){
+ int16_t tmp;
+ uint8_t changeflag=1;
+ lcd_clrscr();
+ if (eeprom_read_byte((uint8_t *)0x0) == 19){
+ changeflag=0;
+ // ok magic number matches accept values
+ tmp=eeprom_read_word((uint16_t *)0x04);
+ if (tmp != set_val[1]){
+ changeflag=1;
+ }
+ tmp=eeprom_read_word((uint16_t *)0x02);
+ if (tmp != set_val[0]){
+ changeflag=1;
+ }
+ }
+ delay_ms_uartcheck(1); // check for uart without delay
+ if (changeflag){
+ lcd_puts_P("setting stored");
+ eeprom_write_byte((uint8_t *)0x0,19); // magic number
+ eeprom_write_word((uint16_t *)0x02,set_val[0]);
+ eeprom_write_word((uint16_t *)0x04,set_val[1]);
+ }else{
+ if (bpress> 2){
+ // display software version after long press
+ lcd_puts_P(SWVERSION);
+ lcd_gotoxy(0,1);
+ lcd_puts_P("tuxgraphics.org");
+ }else{
+ lcd_puts_P("already stored");
+ }
+ }
+ delay_ms_uartcheck(200);
+ delay_ms_uartcheck(200);
+ delay_ms_uartcheck(200);
+}
+
+// check the keyboard
+static uint8_t check_buttons(void){
+ uint8_t uartprint_ok=0;
+ uint8_t cmdok=0;
+#ifdef USE_UART
+ char buf[21];
+#endif
+ //
+#ifdef USE_UART
+ if (uart_has_one_line){
+ if (uartstr[0]=='i' && uartstr[1]=='=' && uartstr[2]!='\0'){
+ set_val[0]=atoi(&uartstr[2]);
+ if(set_val[0]>I_MAX){
+ set_val[0]=I_MAX;
+ }
+ if(set_val[0]<0){
+ set_val[0]=0;
+ }
+ uartprint_ok=1;
+ }
+ // version
+ if (uartstr[0]=='v' && uartstr[1]=='e'){
+ uart_sendstr_p(P(" "));
+ uart_sendstr_p(P(SWVERSION));
+ uart_sendstr_p(P("\r\n"));
+ cmdok=1;
+ }
+ // store
+ if (uartstr[0]=='s' && uartstr[1]=='t'){
+ store_permanent();
+ uartprint_ok=1;
+ }
+ if (uartstr[0]=='u' && uartstr[1]=='=' && uartstr[2]!='\0'){
+ set_val[1]=atoi(&uartstr[2]);
+ if(set_val[1]>U_MAX){
+ set_val[1]=U_MAX;
+ }
+ if(set_val[1]<0){
+ set_val[1]=0;
+ }
+ uartprint_ok=1;
+ }
+ // help
+ if (uartstr[0]=='h' || uartstr[0]=='H'){
+ uart_sendstr_p(P(" Usage: u=V*10|i=mA/10|store|help|version\r\n"));
+ uart_sendstr_p(P(" Examples:\r\n"));
+ uart_sendstr_p(P(" set 6V: u=60\r\n"));
+ uart_sendstr_p(P(" max 200mA: i=20\r\n"));
+ cmdok=1;
+ }
+ if (uartprint_ok){
+ cmdok=1;
+ uart_sendstr_p(P(" ok\r\n"));
+ }
+ if (uartstr[0]!='\0' && cmdok==0){
+ uart_sendstr_p(P(" command unknown\r\n"));
+ }
+
+ int_to_dispstr(measured_val[1],buf,1);
+ uart_sendstr(buf);
+ uart_sendchar('V');
+ uart_sendchar(' ');
+ uart_sendchar('[');
+ int_to_dispstr(set_val[1],buf,1);
+ uart_sendstr(buf);
+ uart_sendchar(']');
+ uart_sendchar(',');
+ int_to_dispstr(measured_val[0],buf,2);
+ uart_sendstr(buf);
+ uart_sendchar('A');
+ uart_sendchar(' ');
+ uart_sendchar('[');
+ int_to_dispstr(set_val[0],buf,2);
+ uart_sendstr(buf);
+ uart_sendchar(']');
+ if (is_current_limit()){
+ uart_sendchar('I');
+ }else{
+ uart_sendchar('U');
+ }
+ uart_sendchar('>');
+ uart_has_one_line=0;
+ uartstrpos=0;
+ }
+#endif
+ if (check_u_button(&(set_val[1]))){
+ if(set_val[1]>U_MAX){
+ set_val[1]=U_MAX;
+ }
+ return(1);
+ }
+ if (check_i_button(&(set_val[0]))){
+ if(set_val[0]>I_MAX){
+ set_val[0]=I_MAX;
+ }
+ return(1);
+ }
+ if (check_store_button()){
+ store_permanent();
+ return(2);
+ };
+ return(0);
+}
+
+int main(void)
+{
+ char out_buf[21];
+ uint8_t i=0;
+ uint8_t ilimit=0;
+
+#ifndef USE_UART
+ // debug led, you can not have an LED if you use the uart
+ DDRD|= (1<<DDD0); // LED, enable PD0, LED as output
+ LEDOFF;
+#endif
+
+ init_dac();
+ lcd_init();
+ init_kbd();
+ set_val[0]=15;set_val[1]=50; // 150mA and 5V
+ if (eeprom_read_byte((uint8_t *)0x0) == 19){
+ // ok magic number matches accept values
+ set_val[1]=eeprom_read_word((uint16_t *)0x04);
+ set_val[0]=eeprom_read_word((uint16_t *)0x02);
+ }
+#ifdef USE_UART
+ uart_init();
+#endif
+ sei();
+ init_analog();
+ while (1) {
+ i++;
+ // due to electrical interference we can get some
+ // garbage onto the display especially if the power supply
+ // source is not stable enough. We can remedy it a bit in
+ // software with an ocasional reset:
+ if (i==50){ // not every round to avoid flicker
+ lcd_reset();
+ i=0;
+ }
+ lcd_home();
+ // current
+ measured_val[0]=adc_i_to_disp(getanalogresult(0));
+ set_val_adcUnits[0]=disp_i_to_adc(set_val[0]);
+ set_target_adc_val(0,set_val_adcUnits[0]);
+ // voltage
+ measured_val[1]=adc_u_to_disp(getanalogresult(1),measured_val[0]);
+ set_val_adcUnits[1]=disp_u_to_adc(set_val[1])+disp_i_to_u_adc_offset(measured_val[0]);
+ set_target_adc_val(1,set_val_adcUnits[1]);
+ ilimit=is_current_limit();
+
+
+ // voltage
+#ifdef DEBUGDISP
+ itoa(getanalogresult(1),out_buf,10);
+#else
+ int_to_dispstr(measured_val[1],out_buf,1);
+#endif
+ lcd_puts(out_buf);
+ lcd_puts("V [");
+#ifdef DEBUGDISP
+ itoa(set_val_adcUnits[1],out_buf,10);
+#else
+ int_to_dispstr(set_val[1],out_buf,1);
+#endif
+ lcd_puts(out_buf);
+ lcd_putc(']');
+ delay_ms_uartcheck(1); // check for uart without delay
+ if (!ilimit){
+ // put a marker to show which value is currenlty limiting
+ lcd_puts("<- ");
+ }else{
+ lcd_puts(" ");
+ }
+
+ // current
+ lcd_gotoxy(0,1);
+#ifdef DEBUGDISP
+ itoa(getanalogresult(0),out_buf,10);
+#else
+ int_to_dispstr(measured_val[0],out_buf,2);
+#endif
+ lcd_puts(out_buf);
+ lcd_puts("A [");
+#ifdef DEBUGDISP
+ itoa(set_val_adcUnits[0],out_buf,10);
+#else
+ int_to_dispstr(set_val[0],out_buf,2);
+#endif
+ lcd_puts(out_buf);
+ lcd_putc(']');
+ if (ilimit){
+ // put a marker to show which value is currenlty limiting
+ lcd_puts("<- ");
+ }else{
+ lcd_puts(" ");
+ }
+
+ // the buttons must be responsive but they must not
+ // scroll too fast if pressed permanently
+ if (check_buttons()==0){
+ // no buttons pressed
+ delay_ms_uartcheck(80);
+ bpress=0;
+ if (check_buttons()==0){
+ // no buttons pressed
+ delay_ms_uartcheck(80);
+ }else{
+ bpress++;
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ }
+ }else{
+ // button press
+ if (bpress > 10){
+ // somebody pressed permanetly the button=>scroll fast
+ delay_ms_uartcheck(120);
+ }else{
+ bpress++;
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ delay_ms_uartcheck(180);
+ }
+ }
+ }
+ return(0);
+}
+