Recent Posts

1

Beginners / Re: Jutter calculation ?

« Last post by GigaJoe on Today at 04:10:49 am »

Im playing with DSS  FY-6900
and as many complain about jitter signal output , I'm trying to actually characterize it in numbers.

so gen source is 10Mhz OCXO now .. and I can run output up to 60M  ; that frequency on pictures  is actually 10.000 000.1

my guess I need to pick some most horrendous frequency but I don't know what is that ;  like completely uneven , random one ?

2

Buy/Sell/Wanted / Re: FS: Motorola MVME 202, 310, 211

« Last post by ZGoode on Today at 04:09:02 am »

I found 4 pcs of HP 01650-63203 100kOhm Termination Adapter for logic analyzer. Date code is 39/93. And it doesn't seem like they have been used much. They come with plastic bag and manuals.
Anyone interested?

I'd probably be interested in those if the shipping and price is reasonable.  How much would it cost to ship to Gilbert, AZ 85295 in the USA?

3

Beginners / Re: Need a (slightly) random signal ? Hers an idea, using CDS light sensor.

« Last post by RJSV on Today at 04:04:49 am »

Picture of solar night lamp.

4

Beginners / Re: Automatic golf ball dispenser

« Last post by BTO on Today at 04:01:55 am »

You can use an Arduino. Here is an example: https://www.instructables.com/Golf-ball-dispenser/

You can indeed, but i think his point was YOU DON'T NEED TO. Which.. I agree, You don't need to . But i was trying to explain to him
that we were trying to help the O.P. with ideas.
Bottom line is, he seems to have some aggression in him, Maybe he's young, Not sure.

5

Test Equipment / Re: Siglent SSA 3021X... Ooops

« Last post by Joel_l on Today at 04:00:07 am »

Its already in pieces. I was doing some tx measurements and left my attenuator out when making a change. The SA got 6 Watts pumped into it. It is not working properly now, levels are wrong, frequency is also off a little, I worry that might be a bigger issue. Measurements were fine until my screwup.

6

Beginners / Re: Jutter calculation ?

« Last post by ataradov on Today at 03:54:48 am »

This is not a lot of period jitter.  Next step is to move away multiple periods until there is a measurable value and then divide by the number of periods. But the more periods you move away, the less meaningful this number becomes from the characterization point of view. It is still good enough for basic estimation.

What is the signal source and what is the anticipated jitter?

7

Microcontrollers / Re: CH32V003 ADC scan mode - DMA required?

« Last post by jlsilicon on Today at 03:53:40 am »

Here is a simple Example of ADC without DMA.

Code: [Select]


/*
  Create project as : ch32v003 - f4p6  (- Not 103/203)
  - copy main.c from /EVT/EXAM/...

 WORKS :
*/


#include "debug.h"


//


void ADCConfig(void) ;


#define ANALOG1_PIN       GPIO_Pin_4
#define ANALOG1_PORT    GPIOD


uint16_t  adcReading ;
int       adcFlag = 1 ;


void ADCConfig(void)
{
    ADC_InitTypeDef   ADC_InitStructure  = {0};
    GPIO_InitTypeDef  GPIO_InitStructure = {0};
    NVIC_InitTypeDef  NVIC_InitStructure = {0};

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
    RCC_ADCCLKConfig(RCC_PCLK2_Div8);

    GPIO_InitStructure.GPIO_Pin  = ANALOG1_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_Init(ANALOG1_PORT, &GPIO_InitStructure);

    ADC_DeInit(ADC1);
    ADC_InitStructure.ADC_Mode               = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode       = DISABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStructure.ADC_ExternalTrigConv   = ADC_ExternalTrigInjecConv_None;
    ADC_InitStructure.ADC_DataAlign          = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfChannel       = 1;
    ADC_Init(ADC1, &ADC_InitStructure);

    ADC_InjectedSequencerLengthConfig(ADC1, 1);
    ADC_InjectedChannelConfig(ADC1, ADC_Channel_7, 1, ADC_SampleTime_241Cycles);
    ADC_ExternalTrigInjectedConvCmd(ADC1, DISABLE);

    NVIC_InitStructure.NVIC_IRQChannel                   = ADC_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    ADC_Calibration_Vol(ADC1, ADC_CALVOL_50PERCENT);
    ADC_ITConfig(ADC1, ADC_IT_JEOC, ENABLE);
    ADC_Cmd(ADC1, ENABLE);

    ADC_ResetCalibration(ADC1);

    while (ADC_GetResetCalibrationStatus(ADC1))
     {}

    ADC_StartCalibration(ADC1);
    while (ADC_GetCalibrationStatus(ADC1))
     {}

}


void ADC1_IRQHandler() __attribute__((interrupt("WCH-Interrupt-fast")));

/**

 * The function ADC1_IRQHandler handles the interrupt for ADC1 and prints the value of the injected

 * conversion.

 */

void ADC1_IRQHandler()
{

    if (ADC_GetITStatus(ADC1, ADC_IT_JEOC) == SET)
    {
        adcFlag = 1;

        ADC_ClearITPendingBit(ADC1, ADC_IT_JEOC);

    }

}


//


/*********************************************************************
 * @fn      main
 *
 * @brief   Main program.
 *
 * @return  none
 */

int main(void)
{
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    SystemCoreClockUpdate();
    Delay_Init();

    USART_Printf_Init(115200);
     printf(\r\n : ADC Test : r\n",SystemCoreClock);
     printf("SystemClk:%d\r\n",SystemCoreClock);
     printf( "ChipID:%08x\r\n", DBGMCU_GetCHIPID() );

    adcFlag = 1 ;

    ADCConfig();

    ;

    while(1)
    {

        if( adcFlag == 1 )
        {
              adcReading = ADC_GetInjectedConversionValue( ADC1 , ADC_InjectedChannel_1 );
              adcReading = (adcReading * 325)/100; // Converting to real voltage w.r.t. VCC 3.3V, 0.985 multiplier factor is used with 3.3V for calibration. 330 * 0.985 = 325. This was as per my board, you might need to do it with different multiplier value.
              adcFlag = 0;

               printf(" AdcIn = %d \r\n" , adcReading );

              // Restart Read ADC : //
              ADC_SoftwareStartInjectedConvCmd(ADC1, ENABLE);

               Delay_Ms(500);
        }

    }

return(0);
}

///



8

Beginners / Re: Jutter calculation ?

« Last post by GigaJoe on Today at 03:45:50 am »

Okey ! Thanks !

so period ...  1nS , limit


hmm ... hard to say how much is that ...

or I measure something incorrectly, again ....

9

Microcontrollers / Re: ELM327 (serial to OBDII CANbus converter) discontinued

« Last post by chickenHeadKnob on Today at 03:45:36 am »

Are any cars still using something other than CAN?

Tesla's are heavily into using ethernet now.
https://ilovetesla.com/a-deep-dive-into-teslas-revolutionary-etherloop-technology/

10

Repair / Re: Mig welder wire feeder controller board not working

« Last post by .RC. on Today at 03:43:53 am »

Thanks for the replies, Here is an updated mirrored photo with some of the pin outs identified.  Also have a photo of the back of the board which the pin outs will line up with the mirrored photo.

The relay points are a bit burnt, but I did test it with the bench power supply and it still works.

The welder is a 250SE, but the wirefeeder is separate, it is a 2R model 705995

I have tested the torch trigger, no issues there.