MSP430FR6043: Some questions about pulses which is generated on the dedicated CH0_OUT pin

Hello!

Our company plan to design a water meter using msp430fr6043. We have modified the capacitances and resistances on the EVM430-FR6043 in Figure 1. We used the code examples for msp430fr6043 which named msp430fr6043_saph_01.c, and the code is then posted. We used an oscilloscope to view the waveform of the CH0_OUT pin, as shown in Figure 2,3. The problem we faced was that the oscilloscope waveform was not a square wave, and we suspected that it was not an excitation signal. We want to generate an incentive signal first, but we do not know what is wrong with this, please inform us, thank you very much!

Figure 1

Figure 2

Figure 3

msp430fr6043_saph_01.c

#include <msp430.h>

#define OSCTYPE__CRYSTAL OSCTYPE_0

void HSPLL_init(void);

int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop WDT

// Configure P1.5 as output for LED
P1OUT &= ~BIT5;
P1DIR |= BIT5;

// Disable the GPIO power-on default high-impedance mode to activate
// previously configured port settings
PM5CTL0 &= ~LOCKLPM5;

// Clock System Setup
CSCTL0_H = CSKEY_H; // Unlock CS registers
CSCTL1 = DCOFSEL_3 | DCORSEL; // Set DCO to 8MHz
// Set SMCLK = MCLK = DCO, ACLK = VLOCLK
CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;
CSCTL3 = DIVA__1 | DIVS__8 | DIVM__8; // MCLK = SMCLK = 1MHz
CSCTL0_H = 0; // Lock CS registers

HSPLL_init(); // Initialize the HSPLL and wait for it to lock

// Set up the PPG settings
SAPHKEY = KEY; // Unlock the SAPH registers
SAPHPGC = PLEV_0 | PPOL_0 | 0x000A; // 10 excitation pulses, 0 stop pulses, output low when inactive, high polarity
SAPHPGLPER = 40; // Low phase = 40 HSPLL cycles = 500ns
SAPHPGHPER = 40; // High phase = 40 HSPLL cycles = 500ns
SAPHPGCTL = TRSEL_2 | PPGCHSEL_0 | PGSEL_0; // TA2.1 trigger, CH0 output, register mode

// Set up the PHY to output PPG on dedicated CH0_OUT pin
SAPHOSEL = PCH0SEL__PPGSE; // Output PPG

// Enable the PPG
SAPHPGCTL |= PPGEN;

// Configure TA2.1 for ~1/sec to trigger the pulse generation and toggle LED
TA2CCR0 = 9400;
TA2CCR1 = 4700;
TA2CCTL1 = OUTMOD_7 | CCIE; // Enable output signal to trigger PPG, enable Interrupt
TA2CTL = TASSEL__ACLK | TACLR | MC__UP; // Timer sourced from ACLK (VLO), clear timer

while(1)
{
__bis_SR_register(LPM0_bits | GIE); // Enter LPM3 w/interrupt
__no_operation(); // For debug
}
}

// Timer A2 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER2_A1_VECTOR
__interrupt void Timer2_A1_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER2_A1_VECTOR))) Timer2_A1_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch(__even_in_range(TA2IV, TAIV__TAIFG))
{
case TAIV__NONE: break; // No interrupt
case TAIV__TACCR1:
P1OUT ^= BIT5; // Toggle LED to show new cycle
break;
case TAIV__TAIFG: break; // overflow
default: break;
}
}

void HSPLL_init(void)
{
// Configure USSXT Oscillator
HSPLLUSSXTLCTL = OSCTYPE__CRYSTAL | USSXTEN;

// Set up timer to wait in LPM for crystal stabilization time = 4096 clocks for crystal resonator.
// For 8MHz XTAL, 4096 clocks = 512us. Using VLO = 9.4kHz, wait 5 timer clock cycles = 532us.
TA4CCR0 = 5;
TA4CCTL0 = CCIE; // Enable Interrupt
TA4CTL = TASSEL__ACLK | TACLR | MC__UP; // Timer sourced from ACLK (VLO), clear timer
__bis_SR_register(LPM3_bits | GIE); // Enter LPM3 w/interrupt
__no_operation(); // For debug

// Check if oscillator is stable
while((HSPLLUSSXTLCTL & OSCSTATE) == 0);

// Output oscillator on pin
HSPLLUSSXTLCTL &= ~XTOUTOFF;

// Init PLL
// Use the PLLM setting to get 80MHz output from our 8MHz input
// Equation: PLL output clock frequency x 2 = input clock frequency x (PLLM+1)
// Input clock frequency = 8MHz
// Desired PLL output clock frequency = 80MHz
// PLLM = 19
HSPLLCTL = PLLM4 | PLLM1 | PLLM0 | PLLINFREQ; //PLLM = 19, PLL input frequency > 6MHz

// Power up the UUPS to start the PLL
UUPSCTL |= USSPWRUP;

// Wait for UUPS to power up
while((UUPSCTL & UPSTATE_3) != UPSTATE_3);

// Wait for PLL to lock
while(!(HSPLLCTL & PLL_LOCK));
}

// Timer A4 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER4_A0_VECTOR
__interrupt void Timer4_A0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER4_A0_VECTOR))) Timer4_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{
// Stop the timer and wake from LPM
TA4CTL = MC__STOP;
__bic_SR_register_on_exit(LPM3_bits | GIE);
__no_operation();
}

Yale Li：

I post your questions to the relevant engineer:

https://e2e.ti.com/support/microcontrollers/msp-low-power-microcontrollers-group/msp430/f/msp-low-power-microcontroller-forum/1212458/msp430fr6043-some-questions-about-pulses-which-is-generated-on-the-dedicated-ch0_out-pin

Please waiting for reply. Thanks for your patience!

,

Yale Li：

We have a water meter example code based on FR6043. You can download it from this link. https://www.ti.com/tool/download/USS-SWLIB-WATER

And there are also app note you can check with. https://www.ti.com/lit/ug/tidues5a/tidues5a.pdf

,

measure CHANG：

Thank you very much for your reply, but we have read relevant articles and downloaded the code you provided. Since the encapsulation of this code is too high, it is inconvenient to modify the code. So we want to use the examples to send pulses, receive pulses, store data, and calculate the time of flight step by step. So why is my oscilloscope display output pulse not square wave?

,

Yale Li：

I have followed these information up.

,

Yale Li：

How do you get the oscilloscope figure? Have you attached the transducer on the CHx_OUT pin and then measure the signal?

,

measure CHANG：

Thank you very much. I found that the parameters of the oscilloscope were wrong, and the waveform in the figure was actually noise. After adjusting the parameters, the oscilloscope could display square waves. But when capturing the waveform, the data was placed in the result array, and I copied the values out. There were only 256. The waveform drawn in excel did not show the receiving pulse. How can I solve this problem?

,

Yale Li：

I have followed these information up.

,

Yale Li：

It might related to the configuration of the SDHS ADC or the capture sequence. 

Have you tried with template example first? The ADC capture code is open to the customer in the code. 

,

measure CHANG：

Yes, the graph is drawn using a template example. The code is as follows. I'm confused about the waveform of the values in the result array. Because I can see waveform on oscilloscope when I captured X_CH0_OUT and X_CH1_IN, as shown in Figure 1 & 2, but not in ccs, as shown in Figure 3. I don't know which step I made a mistake, what should I do?

Figure 1

Figure 2

Figure 3

//******************************************************************************
//MSP430FR60xx Demo - SDHS sampling at 8MSPS and DTC transfer results to RAM
//
//Description: Configure the SDHS for stand-alone use (register mode) at 8MSPS.
//Use the DTC to transfer the results to an array in RAM named "results" (located
//in LEA RAM at 0x5000). Convert array back to input voltage using:
//V = (adc_code * (f_s/2))/(gain*7FF) + Bias
//where,adc_code is the ADC result(16-Bit Signed Int),f_s = .755V(Full-scale voltage),
//gain = 10^(0.1/20)) = approximately 1, Bias = .9V, 7FF = 2047
//
//***NOTE: On TS-Board, remove JP14, put SIG on inner pin and GND to outer pin.
//Valid input range is 600mV - 1200mV, as configured.***
//MSP430FR6043
//---------------
///|\||
//| ||
//--|RST|
//|P1.5|---> LED
//||-USSXTIN
//||-USSXTOUT
//|CH0_IN|<--- input signal
//
//Gary Gao & Matt Calvo
//Texas Instruments Inc.
//February 2018
//Built with IAR Embedded Workbench V7.10 & Code Composer Studio V7.3
//******************************************************************************
#include <msp430.h>#define OSCTYPE__CRYSTAL OSCTYPE_0void HSPLL_init(void);#if defined(__TI_COMPILER_VERSION__)
#pragma DATA_SECTION(results, ".leaRAM")
#pragma RETAIN(results)int results[800] = {0};
#elif defined(__IAR_SYSTEMS_ICC__)
#pragma location=0x5000
__no_initint results[800];
#pragma required = results
#elif defined(__GNUC__)int results[800] __attribute__ ((section (".leaRAM"), used));
#else
#error Compiler not supported!
#endifint main(void)
{WDTCTL = WDTPW | WDTHOLD;// Stop WDT// Configure P1.5 as output for LEDP1OUT &= ~BIT5;P1DIR |= BIT5;// Disable the GPIO power-on default high-impedance mode to activate// previously configured port settingsPM5CTL0 &= ~LOCKLPM5;// Configure one FRAM waitstate as required by the device datasheet for MCLK// operation beyond 8MHz _before_ configuring the clock system.FRCTL0 = FRCTLPW | NWAITS_1;// Clock System SetupCSCTL0_H = CSKEY_H;// Unlock CS registers// Per Device Errata(CS12) set divider to 4 before changing frequency to// prevent out of spec operation from overshoot transientCSCTL3 = DIVA__4 | DIVS__4 | DIVM__4;// Set all corresponding clk sources to divide by 4 for errata(CS12)CSCTL1 = DCOFSEL_4 | DCORSEL;// Set DCO to 16MHz// Delay by ~10us to let DCO settle. 60 cycles = 20 cycles buffer + (10us / (1/4MHz))__delay_cycles(60);CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;// Set all dividers to 1 for 16MHz operationCSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;// MCLK = SMCLK = 16MHzCSCTL0_H = 0;// Lock CS registers//Setup SAPH Bias Register ControlledSAPHKEY = KEY;SAPHBCTL &= ~ASQBSC;//Tx bias and Rx bias switches control source select; 0h (R/W) = Bias switches are controlled by SAPHBCTL.CH0EBSW, SAPHBCTL.CH1EBSW, SAPHBCTL.PGABSW bits (register mode)SAPHBCTL |= CPDA;//Enable the power supply (Charge Pump) for the the input multiplexer during data acquisition. 1h (R/W) = Keep turning on the charge pump during data acquisition.SAPHICTL0 = 0;//Input Multiplexer Channel SelectSAPHKEY = KEY+1;//Setup the SDHS with register modeSDHSCTL0 = TRGSRC_0 | AUTOSSDIS_1 | DFMSEL_0;// Software trigger,Left, 2s complement formatSDHSCTL1 = OSR_0;// OSR = 10 (80MHz/10 = 8MSPS). CS must set MCLK >= 8MHz.SDHSCTL2 = 799;// SMPSZ = 255+1 samplesSDHSCTL6 = 0x20;// PGA Gain 0.1 dBSDHSCTL7 = 0xC;// MODOPTI = 0xC (80MHz PLL output frequency)SDHSDTCDA = 0x800;// DTC transfer data to start of LEA RAMSDHSIMSC = ACQDONE;// Enable acquisition done interrupt (after 256 samples transferred)SDHSCTL3 = TRIGEN_1;// Enable triggerSDHSCTL4 = SDHSON;// Turn on SD and start conversion__delay_cycles(640);// Delay for PGA worst case 40us settling timeHSPLL_init();// Initialize the HSPLL and wait for it to lock///*SAPH// Set up the PPG settingsSAPHKEY = KEY;// Unlock the SAPH registersSAPHPGC = PLEV_0 | PPOL_0 | 0x000A;// 10 excitation pulses, 0 stop pulses, output low when inactive, high polaritySAPHPGLPER = 40;// Low phase = 40 HSPLL cycles = 500nsSAPHPGHPER = 40;// High phase = 40 HSPLL cycles = 500nsSAPHPGCTL = TRSEL_2 | PPGCHSEL_0 | PGSEL_0; // TA2.1 trigger, CH0 output, register mode// Set up the PHY to output PPG on dedicated CH0_OUT pinSAPHOSEL = PCH0SEL__PPGSE;// Output PPG// Enable the PPGSAPHPGCTL |= PPGEN;
//SAPH*/// Configure TA2.1 for 1/sec to trigger the pulse generation and toggle LEDTA2CCR0 = 9400;TA2CCR1 = 4700;TA2CCTL1 = OUTMOD_7 | CCIE;// Enable output signal to trigger PPG, enable InterruptTA2CTL = TASSEL__ACLK | TACLR | MC__UP; // Timer sourced from ACLK (VLO), clear timerwhile(1){__bis_SR_register(LPM0_bits | GIE); // Enter LPM0 w/interrupt__no_operation();// For debug}
}// Timer A2 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER2_A1_VECTOR
__interrupt void Timer2_A1_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER2_A1_VECTOR))) Timer2_A1_ISR (void)
#else
#error Compiler not supported!
#endif
{switch(__even_in_range(TA2IV, TAIV__TAIFG)){case TAIV__NONE:break;// No interruptcase TAIV__TACCR1:SDHSCTL4&= ~SDHSON;SDHSCTL5 &= ~SSTART;SDHSCTL3 = 0;SDHSDTCDA = 0x800;SDHSCTL3 = TRIGEN_1;SDHSCTL4 = SDHSON;SDHSCTL5 |= SSTART;// Start conversion__no_operation();break;case TAIV__TAIFG:// overflow__no_operation();break;default: break;}
}// SDHS interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = SDHS_VECTOR
__interrupt void SDHS_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(SDHS_VECTOR))) SDHS_ISR (void)
#else
#error Compiler not supported!
#endif
{switch(__even_in_range(SDHSIIDX, IIDX_6)){case IIDX_0:break;// No interruptcase IIDX_1:__no_operation();break;// OVF interruptcase IIDX_2:// ACQDONE interruptP1OUT ^= BIT5;// Toggle LED to show new cyclelll__delay_cycles(1000);__no_operation();// Put breakpoint here to view resultsbreak;case IIDX_3:break;// SSTRG interruptcase IIDX_4:break;// DTRDY interruptcase IIDX_5:break;// WINHI interruptcase IIDX_6:break;// WINLO interruptdefault: break;}
}void HSPLL_init(void)
{// Configure USSXT OscillatorHSPLLUSSXTLCTL = OSCTYPE__CRYSTAL |USSXTEN;// Set up timer to wait in LPM for crystal stabilization time = 4096 clocks for crystal resonator.// For 8MHz XTAL, 4096 clocks = 512us. Using VLO = 9.4kHz, wait 5 timer clock cycles = 532us.TA4CCR0 = 5;TA4CCTL0 = CCIE;// Enable InterruptTA4CTL = TASSEL__ACLK | TACLR | MC__UP; // Timer sourced from ACLK (VLO), clear timer__bis_SR_register(LPM3_bits | GIE);// Enter LPM3 w/interrupt__no_operation();// For debug// Check if oscillator is stablewhile((HSPLLUSSXTLCTL & OSCSTATE) == 0);// Output oscillator on pinHSPLLUSSXTLCTL &= ~XTOUTOFF;// Init PLL// Use the PLLM setting to get 80MHz output from our 8MHz input// Equation: PLL output clock frequency x 2 = input clock frequency x (PLLM+1)// Input clock frequency = 8MHz// Desired PLL output clock frequency = 80MHz// PLLM = 19HSPLLCTL = PLLM4 | PLLM1 | PLLM0 | PLLINFREQ; //PLLM = 19, PLL input frequency > 6MHz// Power up the UUPS to start the PLLUUPSCTL |= USSPWRUP;// Wait for UUPS to power upwhile((UUPSCTL & UPSTATE_3) != UPSTATE_3);// Wait for PLL to lockwhile(!(HSPLLCTL & PLL_LOCK));
}// Timer A4 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER4_A0_VECTOR
__interrupt void Timer4_A0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER4_A0_VECTOR))) Timer4_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{// Stop the timer and wake from LPMTA4CTL = MC__STOP;__bic_SR_register_on_exit(LPM3_bits | GIE);__no_operation();
}

,

Yale Li：

I have already updated your reply.

,

measure CHANG：

I saw the answer from the relevant engineer. How to communicate offline?

,

Yale Li：

I will discuss with Cash offline, and then get back to you. Thanks for your patience.

,

Yale Li：

What‘s the exact demo you use(the code you upload)? Could you please provide me the path?

And what is the difference you made from the original code?

measure CHANG 说：

According to the waveform, we think the transceivers are working normally.

measure CHANG 说：but not in ccs, as shown in Figure 3

So we think that the configurations of ADC in code may be improper.

,

measure CHANG：

Thank you for your answer. I used msp430fr6043_saph_01.c and msp430fr6043_sdhs_01. c in  MSP430FR6043_MSP430FR6041_MSP430FR5043_MSP430FR5041_Code_Examples from the website: https://www.ti.com.cn/product/zh-cn/MSP430FR6043#software-development  .  See Figure 1 for details.

I added saph excitation in msp430fr6043_sdhs_01.c file and modified the value of array, sampling value and gain. See Figure 2, 3 for details.

Figure 1 

Figure 2

Figure 3

,

Yale Li：

measure CHANG 说：

Figure 1 

As we mentioned before, this may be the reason why you cannot demonstrate a whole waveform based on the ADC result stored in the device.

And, the demo in the link you posted is the general demo of these series devices. We have specialized SDK for USS application:

https://www.ti.com.cn/tool/cn/MSP-ULTRASONIC-DESIGN-CENTER

It's include the base USS project and a GUI. After you programmed the base project, you can use the GUI to configure the USS parameters, capture the waveform, calculate the relevant result, etc.. It's easy to create your own application and test it.

The relevant document is in the link and GUI–>help.

,

measure CHANG：

Thank you for your answer. I used the GUI and downloaded the corresponding program on the development board. When I read the program, I was a little confused. The "MSP430FR6xx Family User's Guide" file states the formula shown in Figure 1. Combined with the formula and the HSPLLCTL register, the output clock frequency is 68MHz, but the program enters 72Mhz, as shown in Figure 2. Is there any problem with this?

Figure 1

Figure 2

,

measure CHANG：

Hello, I can't understand the parameter "Start PPG Count", may I ask what time it refers to?

,

measure CHANG：

What is the basis of parameter selection here? Is it related to hardware circuit? What is the effect of choosing different impedance on the actual measurement? Is it related to the analog to digital conversion offset? Thanks!

,

Yale Li：

About the meaning and setting of the parameters, you can reference this page to understand:

file:///C:/ti/msp/USS_02_30_00_03/USS/docs/UserGuide/UserGuide/ch_config.html

,

measure CHANG：

Thank you, but I cannot find how to choose the parameters about BIMP in ch_config.html and MSP430FR6xx Family User's Guide. Could you tell me how to make the seletion?

,

Yale Li：

It's used for the impedance match:

slau367p_MSP430FR58xx, MSP430FR59xx, and MSP430FR6xx Family User's Guide (Rev. P) P506

,

measure CHANG：

Is the interrupt function all written in "USS_Lib_HAL.c"? I configured TA1's interrupt earlier, but why is there no interrupt function about TA1 in "USS_Lib_HAL.c" ?

,

Yale Li：

Hi, I strongly suggest you ask a new question for other issues:

It make us identify and follow up easier. Thanks 

,

measure CHANG：

All right.

,

Yale Li：

Fine. I will close this thread.