; I2C communication with CP2401 and HIH6130 by using DMA #include "msp430.h" ; the actual CPU model is set in ; the project options in IAR PWR EQU BIT2 ; CP2401 PWR pin (input) INT EQU BIT3 ; CP2401 INT pin (output) RSEG CSTACK ; pre-declaration of segment RSEG DATA16_N ; data segment i2cb: DS 4 ; I2C data buffer mode: DS 1 ; 0: display humi, 1: display temp cnt: DS 1 ; I2C sent bytes counter ta_p: DS 2 ; Timer_A period for 1 sec wakeup temp: DS 2 ; storage for temperature humi: DS 2 ; storage for humidity LCD_data: DS 21 ; LCD data RSEG CODE ; code segment reset: mov #SFE(CSTACK), SP ; set up stack mov.w #WDTPW+WDTHOLD, &WDTCTL ; stop watchdog timer bis.b #REFTCOFF, &REFCTL0_L ; disable temp sensor ; I/O ports setup mov.b #0xC8, &P1OUT ; init port mov.b #0xC0, &P1REN ; enable pull-up resistors mov.b #0x37, &P1DIR ; output pins on P1 mov.b #BIT6+BIT7, &P1SEL1 ; activate special functions bis.b #PWR, &P2OUT mov.b #BIT2+BIT1+BIT0, &P2DIR ; configure P2 for output mov.w #0x0F, &PJDIR clr.w &PJOUT bis.w #BIT5+BIT4, &PJSEL0 ; enable Xtal oscillator pins clr.w R11 ; power-up delay dec.w R11 jnz $-2 ; clock setup mov.w #0xFFFF, &ta_p mov.b #0xA5, &CSCTL0_H ; unlock the clock interface mov.b #XT1DRIVE_1, &CSCTL4_L ; crystal drive level clr.w R5 ; initialize cycle counter wco1: bic.b #XT1OFFG, &CSCTL5_L ; clear XT1 fault flag bic.b #OFIFG, &SFRIFG1_L bit.b #OFIFG, &SFRIFG1_L ; test oscillator fault flag jz wco2 ; wait for crystal osc. to start inc.w R5 ; wait for at most 1 second for the jnz wco1 ; oscillator to start mov.w #8192, &ta_p ; Timer_A0 period for 1 sec wco2: clr.w &CSCTL3 ; set 8 MHz MCLK, SMCLK ; DMA_1 setup for I2C write operation mov.w #DMASRCINCR_3+DMASRCBYTE, &DMA1CTL mov.w #UCB0TXBUF, &DMA1DAL ; DMA_1 destination address ; DMA_2 setup for I2C read operation mov.w #DMA0TSEL_18, &DMACTL1 ; triggers for DMA_2 mov.w #DMADSTINCR_3+DMADSTBYTE, &DMA2CTL mov.w #UCB0RXBUF, &DMA2SAL ; DMA_2 source address mov.w #i2cb, &DMA2DAL ; DMA_2 destination address ; I2C setup for eUSCI_B i2c1: bit.b #BIT6, &P1IN ; toggle SCK pin till the data jnz i2c2 ; line goes high bic.b #BIT7, &P1OUT nop nop bis.b #BIT7, &P1OUT jmp i2c1 i2c2: bis.b #UCSWRST, &UCB0CTL1 ; keep I2C module in reset bis.w #UCMODE_3+UCMST+UCSYNC, &UCB0CTLW0 ; I2C master mode mov.w #UCASTP_2, &UCB0CTLW1 ; automatic stop generation mov.w #64, &UCB0BRW ; baudrate = 8MHz / 64 call #Init_CP2401 ; Timer_A0 setup for 1 sec periodic wakeups mov.w #TASSEL_1+TACLR+TAIE, &TA0CTL ; ACLK, int. enable, clear mov.w &ta_p, &TA0CCR0 ; Timer_A0 period bis.w #MC_1, &TA0CTL ; start Timer_A0 in Up mode clr.b &mode ; start with displayhing temp clr.b &cnt jmp lp1 ; request first conversion loop: bis.w #LPM3+GIE, SR ; MAIN LOOP nop ; enter LPM3 sleep mode inc.b &mode ; inc mode mod 2 and.b #0x01, &mode ; if mode=1 then display temp jnz lp2 call #Format_Humi ; display humi call #Display_Value lp1: call #Request_Conversion ; request new temp and humi measurement jmp loop lp2: call #Get_Temp_Humi ; read new temp and humi values call #Format_Temp ; display temp call #Display_Value jmp loop ;===PROCEDURES============================================================== Format_Humi: ; convert humi value into BCD mov.w &humi, R5 mov.w R5, &MPY ; multiply humi sensor value by 100 mov.w #100, &OP2 nop nop nop mov.w &RES0, R10 ; R11:R10 = humi*100 mov.w &RES1, R11 add.w #8192, R10 ; rounding off (add 2^13) addc.w #0, R11 clrc rlc.w R10 rlc.w R11 clrc rlc.w R10 rlc.w R11 ; R11 = (humi*100+2^13)/2^14 fh1: cmp.w #100, R11 ; trancate R11 to [0-99] range jlo fh2 mov.b #99, R11 fh2: clr.w R6 ; storage for 4-digit BCD mov.b #8, R7 ; loop cnt = # of bits fh3: rla.b R11 ; use decimal addition dadd.w R6, R6 ; operation to convert R4 dec.b R7 ; into BCD jnz fh3 ret ; BCD is in R6 ;------------------------------------------------------------------------ Format_Temp: ; convert temp value into BCD mov.w &temp, R5 ; display temp mov.w R5, R6 rram.a #2, R6 ; get rid of 2 lsb's mov.w R6, &MPY ; multiply temp sensor value by 165 mov.w #165, &OP2 nop nop nop mov.w &RES0, R10 ; R11:R10 = temp*165 mov.w &RES1, R11 add.w #8192, R10 ; rounding off (add 2^13) addc.w #0, R11 clrc rlc.w R10 rlc.w R11 clrc rlc.w R10 rlc.w R11 ; R11 = (temp*165+2^13)/2^14 sub.w #40, R11 ; subtract offset (=40) jge fh1 clr.w R11 jmp fh1 ; do BCD conversion ;------------------------------------------------------------------------ Display_Value: ; display value in R6 clr.b &LCD_data+17 ; blank clr.b &LCD_data+8 mov.b R6, R7 ; R7=12 mov.b R7, R8 rram.w #4, R8 ; r8 = 0001 and.b #0x0F, R8 ; r8 = 01 add.b R8, R8 add.w #Table_14_seg, R8 ; r8 = data address mov.w @R8, R10 mov.b R10, &LCD_data+18 ; compose digit 6 swpb R10 mov.b R10, &LCD_data+7 and.b #0x0F, R7 add.b R7, R7 add.w #Table_14_seg, R7 ; r7 = data address mov.w @R7, R10 mov.b R10, &LCD_data+19 ; compose digit 7 swpb R10 mov.b R10, &LCD_data+6 bit.b #0x01, &mode jnz deg_s hum_s: mov.w #Table_14_seg+(2*17), R8 ; H mov.w #Table_14_seg+(2*30), R9 ; U mov.w #Table_14_seg+(2*22), R10 ; M mov.w #Table_14_seg+(2*18), R11 ; I mov.w #Table_14_seg+(2*38), R12 ; % jmp load deg_s: mov.w #Table_14_seg+(2*29), R8 ; T mov.w #Table_14_seg+(2*14), R9 ; E mov.w #Table_14_seg+(2*22), R10 ; M mov.w #Table_14_seg+(2*25), R11 ; P mov.w #Table_14_seg+(2*39), R12 ; * load: mov.w @R8, R7 mov.b R7, &LCD_data+13 ; compose symbol swpb R7 mov.b R7, &LCD_data+12 mov.w @R9, R7 mov.b R7, &LCD_data+14 ; compose symbol swpb R7 mov.b R7, &LCD_data+11 mov.w @R10, R7 mov.b R7, &LCD_data+15 ; compose symbol swpb R7 mov.b R7, &LCD_data+10 mov.w @R11, R7 mov.b R7, &LCD_data+16 ; compose symbol swpb R7 mov.b R7, &LCD_data+9 mov.w @R12, R7 mov.b R7, &LCD_data+20 ; compose symbol swpb R7 mov.b R7, &LCD_data+5 ;=======CP2401 INTERFACE============================================= Write_LCD: bic.b #PWR, &P2OUT ; wake-up CP2401 wd: bit.b #INT, &P1IN ; and wait for wake-up jnz wd mov.w #Disable_Int, R11 ; disable CP2400 interrupts call #Send_CP2401 mov.w #Config_Ports, R11 ; reconfigure all ports for analog mode call #Send_CP2401 mov.w #LCD_data, R11 ; send data call #Send_CP2401 Set_ULP: mov.w #ULP_mode, R11 ; put LCD into ultra low-power mode call #Send_CP2401 bis.b #PWR, &P2OUT ; turn on low-power mode ret ;------------------------------------------------------------------------ Init_CP2401: mov.b #20, &LCD_data ; DMA amount to transfer mov.b #4, &LCD_data+1 ; block write command mov.b #0, &LCD_data+2 ; LCD memory address mov.b #0x80, &LCD_data+3 ; (2 bytes) clr.b &LCD_data+4 ; no blinking mov.b #16, R10 mov.w #LCD_data+5, R11 ; init LCD data area ic1: mov.b #0xFF, 0(R11) inc.w R11 dec.b R10 jnz ic1 bic.b #PWR, &P2OUT ic2: bit.b #INT, &P1IN ; wait for reset pin is up jnz ic2 mov.w #Disable_Int, R11 ; disable CP2400 interrupts call #Send_CP2401 mov.w #Unlock_RTC, R11 ; unlock SmaRTClock interface call #Send_CP2401 mov.w #Load_CAPS, R11 ; load caps value call #Send_CP2401 mov.w #Start_RTC, R11 ; start SmaRTClock oscillator call #Send_CP2401 mov.w #Config_Ports, R11 ; set analog mode for all ports call #Send_CP2401 mov.w #Config_LCD, R11 ; LCD configuration call #Send_CP2401 mov.w #LCD_data, R11 ; set all segments off call #Send_CP2401 mov.w #Enable_LCD, R11 ; start LCD operation call #Send_CP2401 jmp Set_ULP ; enter low-power mode ;------------------------------------------------------------------------ Send_CP2401: mov.b @R11+, R10 mov.w R10, &UCB0TBCNT ; I2C byte counter mov.w R10, &DMA1SZ ; amount of DMA transfer mov.w R11, &DMA1SAL ; DMA_1 source address mov.w #0x3A, &UCB0I2CSA ; CP2401 slave address bic.w #UCSWRST, &UCB0CTLW0 ; clear I2C reset bis.w #UCSTPIE, &UCB0IE ; enable I2C stop interrupt bis.w #DMAEN, &DMA1CTL ; enable DMA transfer bis.w #UCTR+UCTXSTT, &UCB0CTLW0 ; send start condition and write bis.w #LPM0+GIE, SR ; enter LPM0 nop ; remain in LPM0 bic.w #DMAEN, &DMA1CTL ; disable DMA channel 1 bis.w #UCSWRST, &UCB0CTLW0 ; I2C reset ret ;=======HIH6130 INTERFACE================================================ Request_Conversion: mov.w #0x27, &UCB0I2CSA ; HIH6130 slave address bic.w #UCSWRST, &UCB0CTLW0 ; clear I2C reset bis.w #UCSTPIE, &UCB0IE ; enable I2C stop interrupt bis.w #UCTR+UCTXSTT+UCTXSTP, &UCB0CTLW0 ; send start condition and write bis.w #LPM0+GIE, SR ; enter LPM0 nop ; remain in LPM0 bis.w #UCSWRST, &UCB0CTLW0 ; I2C reset ret ;---------------------------------------------------------------------- Get_Temp_Humi: ; read temp from sensor mov.w #4, &UCB0TBCNT ; prepare to receive 4 bytes via I2C mov.w #4, &DMA2SZ ; amount to transfer mov.w #0x27, &UCB0I2CSA ; HIH6130 slave address bic.w #UCTR, &UCB0CTLW0 ; set receiver mode bic.w #UCSWRST, &UCB0CTLW0 ; clear I2C reset bis.w #UCSTPIE, &UCB0IE ; enable I2C stop interrupt bis.w #DMAEN, &DMA2CTL ; enable DMA_2 transfer bis.w #UCTXSTT, &UCB0CTLW0 ; send start condition bis.w #LPM0+GIE, SR ; enter LPM0 nop ; remain in LPM0 bic.w #DMAEN, &DMA2CTL ; disable DMA channel 2 bis.w #UCSWRST, &UCB0CTLW0 ; I2C reset swpb &i2cb ; reverse the bytes order and mov.w &i2cb, &humi ; save received values swpb &i2cb+2 ; in variables humi and temp mov.w &i2cb+2, &temp ret ;====================================================================== I2C_ISR: add &UCB0IV,PC ; add offset to PC reti ; no interrupt reti ; ALIFG break reti ; NACKIFG break reti ; STTIFG break jmp I2end ; STPIFG break reti ; RXIFG3 break reti ; TXIFG3 break reti ; RXIFG2 break reti ; TXIFG2 break reti ; RXIFG1 break reti ; TXIFG1 break reti ; RXIFG0 break reti ; TXIFG0 break reti ; BCNTIFG break reti ; clock low timeout break reti ; 9th bit break I2end: bic.w #LPM0,0(SP) ; wake-up CPU reti ;---------------------------------------------------------------------- TA0_ISR: ; timestamp for every 0.5 sec bic.w #TAIFG, &TA0CTL ; clear Timer_A0 interrupt flag bic.w #LPM3, 0(SP) ; wake-up CPU reti ;=========================================================================== Disable_Int: DB 0x05, 0x04, 0x00, 0x30, 0x00, 0x00 Unlock_RTC: DB 0x05, 0x03, 0x00, 0x0A, 0xA5, 0xF1 Load_CAPS: DB 0x05, 0x04, 0x00, 0x0B, 0x06, 0x00 Start_RTC: DB 0x05, 0x04, 0x00, 0x0B, 0x04, 0x80 Config_Ports: DB 0x08, 0x04, 0x00, 0xB5, 0x00, 0x00, 0x00, 0x00, 0x00 Config_LCD: DB 0x0A, 0x04, 0x00, 0x95, 0x0F, 0x0F, 0xAF, 0x70, 0x00, 0x06, 0x10 Enable_LCD: DB 0x04, 0x03, 0x00, 0xA0, 0x01 ULP_mode: DB 0x05, 0x04, 0x00, 0xA1, 0x80, 0x08 EVEN Table_14_seg: ; def`lkji.cbamngh DW 1110000001110000b ; 0 DW 0000001001100000b ; 1 DW 1100010000110010b ; 2 DW 1000010001110000b ; 3 DW 0010010001100010b ; 4 DW 1010010001010010b ; 5 DW 1110010001010010b ; 6 DW 0000001000011000b ; 7 DW 1110010001110010b ; 8 DW 1010010001110010b ; 9 DW 0110010001110010b ; A DW 1000010101111000b ; B DW 1110000000010000b ; C DW 1000000101111000b ; D DW 1110000000010010b ; E DW 0110000000010010b ; F DW 1110010001010000b ; G DW 0110010001100010b ; H DW 1000000100011000b ; I DW 1100000001100000b ; J DW 0110101000000010b ; K DW 1110000000000000b ; L DW 0110001001100001b ; M DW 0110100001100001b ; N DW 1110000001110000b ; O DW 0110010000110010b ; P DW 1110100001110000b ; Q DW 0110110000110010b ; R DW 1000010001010001b ; S DW 0000000100011000b ; T DW 1110000001100000b ; U DW 0110001000000100b ; V DW 0110100001100100b ; W DW 0000101000000101b ; X DW 0000001000001001b ; Y DW 1000001000010100b ; Z DW 0000010100001010b ; + DW 0000010000000010b ; - DW 0010001001000100b ; % DW 0010010000010010b ; * ;--------------------------------------------------------------------------- COMMON INTVEC ; MSP430 interrupt vectors ORG RESET_VECTOR DW reset ; POR, ext. Reset, Watchdog ORG USCI_B0_VECTOR ; USCI_B vector DW I2C_ISR ORG TIMER0_A1_VECTOR ; Timer_A0 vector DW TA0_ISR END