• Content count

  • Joined

  • Last visited

  • Days Won


blankfield last won the day on May 21

blankfield had the most liked content!

About blankfield

  • Rank
  • Birthday 07/23/1987

Profile Information

  • Gender
  • Location
  • Interests
    From 0 to 1
    From VEE to VCC
  1. OK nothing has happen because I'm interested in TMP006 boosterpack. Some time ago I've bought some TMP006 IC's and they still haven't been assembled onto PCB. I'll send my address via PM. Thanks for clarifying this situation and for interesting prize.
  2. According to last PM message I'm putting my question here, "Hi Bluehash, Is there a reason for skipping me in contest results? All the best, blankfield"
  3. Really nice project especially from software side, Android is fantastic OS because of free development add-on for eclipse. If you're using UART it is easy to make wireless communication via bluetooth. I did something similar with this module and based on this Java code - it's good point to start with android.
  4. It's time to submit own project for the POTM contest. It will be my first attempt . Project name: ATX2CHARGER Short description: Switch your ATX into a car battery charger with msp430g2553 Link: Karol (aka blankfield)
  5. I've edited first post, now all materials are included.
  6. Hi, my project basis only on modification of some feedback resistors, no need to play with trafo. Up to ~17V for typical ATX PSU is maximum value. Above this value you need to rewind or made a new transformer. In my opinion it's to tricky, especially to disassemble fragile core (2 "E" shapes glued together).
  7. Thanks for advice, probably I'll made small transformer on toroidal ferrite bead with symmetrical output and primary:secondary 1:3 ratio, should be ok and can be drive via small mosfet from stellaris MCU.
  8. These mistakes are caused by the scheme organisation, divided into several pages and on the most important page is not clearly enough. TxD RxD pin connections are presented deeper, on page with debugger circuit. Which is trap for young players ;-) . Maybe we should make better schematics, without netlist labels and only for msp430gxxx section, which is most important for beginners. Schemes etc:
  9. I'm working on few projects based on msp430 and recently on lm4f Stellaris. Year ago I've left atmel AVR for TI mcu's and I'm happy of this Cheers ~blankfield~
  10. Hi, i'm looking for simple solution to convert 5V USB to 8-15V simetrical but at least 50mA output. Anyone have a idea do this as simple as possible? I've tested solution with max232 IC - source of simetrical +-8V but current is too low. I will be gratefull for all ideas.
  11. In few words it depends on kind of PWM switching controller which ATX supply is using. I have tested models with TL494 and SG6105 IC's both with success. At first you need to remove all components from 3.3V, 5V, -5V rails, then "upgrade" components in 12V rail to new required voltages and power. After this and based on datasheet you need to provide correct voltages on feedback inputs of switching controller basically from resistor dividers, this step bypass OV, UV, OVC protections for missing rails. Via value change in resistor dividers of feedback it's easy to set output voltage. When I finish a project I will try to provide more detail and complete materials about this topic. Probably final schematic in attachment.
  12. In case of wrong polarity with mosfet switched on, a car battery can provide lot more amps. In this case current is limited only by series resistance of battery, wires, Rds(ON), atx transformer secondary side winding etc. I've made some simulations and conclusion is only one: don't switch this mosfet when battery is in wrong polarity, it's easy to make software protections for this situation. Wrong polarity for circuit is safety, I don't want to add reverse protection diode on high current path because of power losses.
  13. Hi, This is only maximal voltage to drive mosfet (Uds) to achieve desired current. PWM will drop this value. I've made test with resistive load and light bulbs but not with battery, I've measured up to 9A not more because my DMM limit. I have to add some reverse protection diode's on ISENSE and USENSE in parallel and one diode in series with 5V rail. This should protect msp430. MOSFET should protect secondary side of atx, I have to make some simulations in LTspice to check this. I didn't mention that charge process is started only when at least 2V (positive = good polarity) are present on battery terminals. By the way thanks for constructive comments.
  14. Hi everyone, I have idea to use msp430 and hacked atx power supply as a car battery charger. Simply msp430 will be used to control of charge process, different charging current, time, precharging and swichable load for accurate voltage measurement will be available. Done: * hacked atx to 17V * enclosure * schematics * pcb * functional code To do: * firmware development If anyone have some suggestions fell free to post within this topic, I'll be grateful. Simple description of operation: At first voltage measurement is initiated, user set type of car battery, capacity and charge strategy. While charging is started PWM signal control P-MOSFET to set correct current, feedback is taken from 5mR shunt resistor trough RC low-pass filter and software implementation of 3 order Chebyshev LP filter. Every 5 minutes charge process stops, load resistor is applied and voltage reading is taken. During charge process user can see actual voltage, current, elapsed time and estimated period to end of charging. If battery will be accidentally disconnected mcu stops charging process. [uPDATE] 22.12.2012 ====================================================== Results. ATX2CHARGER is now working, I've successfully charged some car batteries. In near future I need to finish firmware, add rest of options etc. Tomorrow I'll add attachments (sorce of firmware and gerbers). Final schematics: PCB: Tests of working unit: All media: main.c: /*==================================================================== * * ATX2CHARGER v1.0 * 2012 by blankfield <> * MSP430G2553 @ 16MHz, 3,3V * ===================================================================*/ /*==================================================================== * * headers and includes * ===================================================================*/ #include <msp430.h> #include <ti/mcu/msp430/csl/CSL.h> #include <stdio.h> #include <string.h> #include "msp430g2553.h" #include "main.h" #include "LCD2x16.h" /*==================================================================== * * constants and definitions * ===================================================================*/ //charge indicator animation const char bat0[8] = {0x0A, 0x1F, 0x11, 0x11, 0x11, 0x11, 0x11, 0x1F}; const char bat1[8] = {0x0A, 0x1F, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x1F}; const char bat2[8] = {0x0A, 0x1F, 0x11, 0x11, 0x11, 0x1F, 0x1F, 0x1F}; const char bat3[8] = {0x0A, 0x1F, 0x11, 0x11, 0x1F, 0x1F, 0x1F, 0x1F}; const char bat4[8] = {0x0A, 0x1F, 0x11, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F}; const char bat5[8] = {0x0A, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F}; #define SWSTART BIT7 //P2.7 - START #define SWF1 BIT7 //P1.7 - F1 #define SWF2 BIT6 //P1.6 - F2 #define FIRNtap 15 //fir lp filter number of tap #define Vref (float)3.3 #define ADCRES (float)1023 #define R7resistor (float)4650 #define R9resistor (float)1005 #define R15resistor (float)0.005 #define Uconstant (float)((Vref/ADCRES)*((R7resistor+R9resistor)/R9resistor)) #define Iconstant (float)((Vref/ADCRES)/(R15resistor)) enum enumdisplay_menu {startup, measure_acc, settings, chargeing_params, chargeing_time, summary}; enum enumcharge_type {emergency, normal, mainterance_free}; enum enumaccu_voltage {U6V, U12V}; enum enumstate {idle, charge, discharge}; #pragma DATA_SECTION(ee_charge_type, ".mydata"); #pragma DATA_SECTION(ee_accu_capacity, ".mydata"); #pragma DATA_SECTION(ee_accu_voltage, ".mydata"); #pragma DATA_ALIGN(ee_charge_type, 1); #pragma DATA_ALIGN(ee_accu_capacity, 1) #pragma DATA_ALIGN(ee_accu_voltage, 1); /*==================================================================== * * variables * ===================================================================*/ //FLASH "EEPROM" VALUES unsigned char ee_charge_type; unsigned char ee_accu_capacity; unsigned char ee_accu_voltage; struct timeformat { char hours; char minutes; char seconds; }time; int time_prescale=0; int measurments[4]; float measured_charge_current = 0; float measured_charge_voltage = 0; float measured_discharge_current = 0; float measured_discharge_voltage = 0; float measured_idle_current = 0; float measured_idle_voltage = 0; float Iavg = 0; float Imax = 0; float Ucellmax = 2.5; float Ucelloptimum = 2.4; char accu_capacity = 75; char accu_voltage = U12V; char charge_type = normal; //char charge_time = 0; char charge_progress = 0; char elapsed_1s = false; char tempstring[20]; float DCV[10]; char display_level = startup; char state = idle; /*==================================================================== * * main() * ===================================================================*/ int main(int argc, char *argv[]){ CSL_init();// Activate Grace-generated configuration __delay_cycles(5000); init_mcu(); _delay_cycles(1000000); LCD2x16_Initialize(); __delay_cycles(5000); LCD2x16_WriteCommand(0x01); __delay_cycles(5000); ADC10CTL0 |= ENC;//Start ADC TA1CCR1 = 0; while(1){ control(); if (elapsed_1s){ sprintf(tempstring,"%1.2f;%1.2f;%1.2f;%1.2f;%1.2f;%1.2f;", measured_idle_voltage,measured_idle_current, measured_charge_voltage,measured_charge_current, measured_discharge_voltage,measured_discharge_current); int i; for (i=0; i<sizeof(tempstring); i++) { while (!(IFG2 & UCA0TXIFG)); UCA0TXBUF = tempstring[i]; } elapsed_1s=false; } switch(display_level){ case startup: menu_redraw(); __delay_cycles(25000000); display_level = measure_acc; menu_redraw(); break; case measure_acc: menu_redraw(); if (!(P2IN & SWSTART)) { beep_sound(); display_level=settings; menu_redraw(); } if (!(P1IN & SWF1)) { beep_sound(); if (accu_voltage == U12V) accu_voltage = U6V; else accu_voltage = U12V; menu_redraw(); } break; case settings: if (!(P2IN & SWSTART) && true) { beep_sound(); time.seconds=0; time.minutes=0; time.hours=0; Iavg=0; display_level = chargeing_params; state = charge; menu_redraw(); } if (!(P1IN & SWF1)) { beep_sound(); accu_capacity += 5; if (accu_capacity > 200) accu_capacity = 5; menu_redraw(); } if (!(P1IN & SWF2)) { beep_sound(); charge_type++; if (charge_type>=3) charge_type=0; menu_redraw(); } break; case chargeing_params: if (!(P2IN & SWSTART)) { beep_sound(); display_level=summary; state = idle; menu_redraw(); } if (!(P1IN & SWF1)) { beep_sound(); display_level=chargeing_time; menu_redraw(); } break; case chargeing_time: if (!(P2IN & SWSTART)) { beep_sound(); display_level=summary; state = idle; menu_redraw(); } if (!(P1IN & SWF1)) { beep_sound(); display_level=chargeing_time; menu_redraw(); } break; case summary: if (!(P2IN & SWSTART)) { beep_sound(); display_level=measure_acc; menu_redraw(); } break; } } } /*==================================================================== * * menu_redraw() * ===================================================================*/ void menu_redraw(void){ LCD2x16_GoTo(0,0); switch(display_level){ case startup: LCD2x16_WriteText("ATX2CHARGER v1.0"); LCD2x16_GoTo(0,1); LCD2x16_WriteText(" by blankfield"); break; case measure_acc: if (measured_idle_voltage <=1){ LCD2x16_WriteText("Check battery, "); LCD2x16_GoTo(0,1); sprintf(tempstring,"%01.2fV is too low ",measured_idle_voltage); LCD2x16_WriteText(tempstring); } else{ sprintf(tempstring,"Battery U=%02.2fV ",measured_idle_voltage); LCD2x16_WriteText(tempstring); LCD2x16_GoTo(0,1); //sprintf(tempstring,"P=%01.0f I= %02.2fA ", TA1CCR1*0.05, measured_idle_current); sprintf(tempstring,"Type F1:%02.0dV ",(accu_voltage*6)+6); LCD2x16_WriteText(tempstring); } break; case settings: sprintf(tempstring,"Set cap F1:%03.0dAh ",accu_capacity); LCD2x16_WriteText(tempstring); LCD2x16_GoTo(0,1); if (charge_type==normal) LCD2x16_WriteText("F2: standard "); if (charge_type==mainterance_free) LCD2x16_WriteText("F2:"); if (charge_type==emergency) LCD2x16_WriteText("F2: emerg.charg."); break; case chargeing_params: sprintf(tempstring,"U=%02.1fV I=%02.1fA", measured_charge_voltage, measured_charge_current); LCD2x16_WriteText(tempstring); LCD2x16_GoTo(0,1); sprintf(tempstring,"U=%02.1fV I=%02.1fA", measured_discharge_voltage, measured_discharge_current); break; case chargeing_time: sprintf(tempstring,"Elapsed %2.0f:%2.0f:%2.0f", time.hours, time.minutes, time.seconds); LCD2x16_WriteText(tempstring); LCD2x16_GoTo(0,1); sprintf(tempstring,"Iavg=%2.2f ", Iavg); LCD2x16_WriteText(tempstring); break; case summary: LCD2x16_WriteText("Finished! "); LCD2x16_GoTo(0,1); sprintf(tempstring,"%2.0f:%2.0f:%2.0f @ %2.2f", time.hours, time.minutes, time.seconds, Iavg); LCD2x16_WriteText(tempstring); break; } } /*==================================================================== * * control() * ===================================================================*/ void control(void){ switch (state){ case idle: TA1CCR1=0; TA1CCR2=0; break; case charge: TA1CCR2=0; if ((measured_charge_voltage < (Ucelloptimum*3*(accu_voltage+1))) && (measured_charge_current < (accu_capacity/5/(charge_type+1))) && (TA1CCR1<1999)){ TA1CCR1++; } if (((measured_charge_voltage > (Ucelloptimum*3*(accu_voltage+1))) || (measured_charge_current > (accu_capacity/5/(charge_type+1)))) && (TA1CCR1>1)){ TA1CCR1--; } if (TA1CCR1 <=100 && measured_charge_voltage >= (Ucelloptimum*3*(accu_voltage+1))){ state = idle; display_level = summary; beep_sound(); } break; case discharge: TA1CCR1=0; TA1CCR2=1000; break; } } /*==================================================================== * * init_mcu() * ===================================================================*/ void init_mcu(void){ WDTCTL = WDTPW + WDTHOLD; char name[18]="AT+NAMEATX2CHARGER"; int i; for (i=0; i<18; i++) { while (!(IFG2 & UCA0TXIFG)); UCA0TXBUF = name[i]; } } /*==================================================================== * * measure() * interrupts from ADC * ===================================================================*/ void measure(void){ time_prescale++; if (time_prescale==999){ elapsed_1s=true; time.seconds++; //increase every 1s if(time.seconds==60){ time.seconds=0; time.minutes++; if(time.minutes==60){ time.minutes=0; time.hours++; } } } switch (state){ case idle: measured_idle_current = measurments[3]*Iconstant; measured_idle_voltage = measurments[0]*Uconstant; break; case charge: measured_charge_current = measurments[3]*Iconstant; Iavg = (Iavg + measured_charge_current)/2; measured_charge_voltage = measurments[0]*Uconstant; break; case discharge: measured_discharge_current = measurments[3]*Iconstant; measured_discharge_voltage = measurments[0]*Uconstant; break; } return; } /*==================================================================== * * beep_sound() * ===================================================================*/ void beep_sound(void){ TA0CCR1 = 1000; __delay_cycles(500000); TA0CCR1 = 0; return; } /*==================================================================== * * fir() * ===================================================================== WinFilter version 0.8 Filter type: Low Pass Filter model: Chebyshev Filter order: 3 Sampling Frequency: 1000 Hz Cut Frequency: 6.000000 Hz Pass band Ripple: 1.000000 dB Coefficents Quantization: float Z domain Zeros z = -1.000000 + j 0.000000 z = -1.000000 + j 0.000000 z = -1.000000 + j 0.000000 Z domain Poles z = 0.981540 + j -0.000000 z = 0.990073 + j -0.036073 z = 0.990073 + j 0.036073 ***************************************************************/ float fir(float NewSample) { float FIRCoef[FIRNtap] = { 0.06499156895458164900, 0.06567519555537033900, 0.06626048168634461600, 0.06674435292740793500, 0.06712913054423083600, 0.06742809591680600000, 0.06768722943723189100, 0.06816788995605341200, 0.06768722943723189100, 0.06742809591680600000, 0.06712913054423083600, 0.06674435292740793500, 0.06626048168634461600, 0.06567519555537033900, 0.06499156895458164900 }; static float x[FIRNtap]; //input samples float y=0; //output sample int n; //shift the old samples for(n=FIRNtap-1; n>0; n--) x[n] = x[n-1]; //Calculate the new output x[0] = NewSample; for(n=0; n<FIRNtap; n++) y += FIRCoef[n] * x[n]; return y; } /*==================================================================== * * flashEraseSegment(int FarPtr) * ===================================================================*/ void flashEraseSegment(int FarPtr){ int *Flash_ptr; // local Flash pointer Flash_ptr = (int *) FarPtr; // Initialize Flash pointer FCTL1 = FWKEY + ERASE; FCTL3 = FWKEY; *Flash_ptr = 0; // dummy write to start erase while (FCTL3 & BUSY ); FCTL1 = FWKEY; FCTL3 = FWKEY + LOCK; } /*==================================================================== * * saveSettings(void) * ===================================================================*/ void saveSettings(void){ flashEraseSegment((int) 0xC000); FCTL1 = FWKEY + WRT; FCTL3 = FWKEY; ee_charge_type = (char)charge_type; ee_accu_capacity = (char)accu_capacity; ee_accu_voltage = (char)accu_voltage; FCTL1 = FWKEY; FCTL3 = FWKEY + LOCK; } /*==================================================================== * * loadSettings(void) * ===================================================================*/ void loadSettings(void){ charge_type = (char)ee_charge_type; accu_capacity = (char)ee_accu_capacity; accu_voltage = (char)ee_accu_voltage; } main.h: #ifndef MAIN_H_ #define MAIN_H_ #define false 0 #define true 1 void menu_redraw(void); void control(void); void init_mcu(void); void buttons(void); void measure(void); void beep_sound(void); float fir(float NewSample); void flashEraseSegment(int FarPtr); void saveSettings(void); void loadSettings(void); #endif /* MAIN_H_ */ LCD2x16.c: // ----------------------------------------------------------------#include "LCD2x16.h"#include "msp430g2553.h"#define RS BIT3 // RS - P2.3 RW - GND#define EN BIT5 // EN - P2.5#define D4 BIT4 // D4 - P1.4#define D5 BIT5 // D5 - P1.5#define D6 BIT0 // D6 - P2.0#define D7 BIT1 // D7 - P2.1//Polish language characters//E6 B9 B3 EA F3 F1 9F 9C A5 BF CA C6 D1 A3 8C D3 AF 8F//? ? ? ? ?