Extracting the data from adc data register in lpc2138 ?

Multiple threads are bad.

But the thread created by Tom Bulloch was a LPC2119 with a significantly different ADC.

But the big issue here (besides the stupidity of spamming threads with same questions) is: what part of the ADC chapter in the user manual of the LPC2138 is unclear?

The user manual very clearly mentions register names.
And it very clearly documents which bits of the registers that contains the analog value.
And it doesn't take too many seconds to look at the code you have posted, and the information in the user manual, and make specific logic decisions about how to go on.

So where are you stuck? What part of the user manual have you read?

Multiple threads are bad.

But the thread created by Tom Bulloch was a LPC2119 with a significantly different ADC.

But the big issue here (besides the stupidity of spamming threads with same questions) is: what part of the ADC chapter in the user manual of the LPC2138 is unclear?

The user manual very clearly mentions register names.
And it very clearly documents which bits of the registers that contains the analog value.
And it doesn't take too many seconds to look at the code you have posted, and the information in the user manual, and make specific logic decisions about how to go on.

So where are you stuck? What part of the user manual have you read?

Hi Sorry for spamming threads. I have read the user manual of lpc2138 (ADC registers). They gave the detailed description about the ADC registers. But i am doing mistake somewhere in the declaring the the registers.

void adc_data(void)
{
                    AD0CR  |= 0x01000000;              /* Start A/D Conversion         */
                    while((AD0DR1 & 0x80000000)==0); //until bit 31 is high (DONE)
                    val = AD0DR1; //read a/d data register 1
                    adc_val = ((val >> 6) & 0x3FF);    // Extract AD result

                    while((AD0DR2 & 0x80000000)==0); //until bit 31 is high (DONE)
                    val1 = AD0DR2; //read a/d data register 2
                    adc_val1 = ((val1 >> 6) & 0x3FF);    // Extract AD result

}

The code executes quite well but the value presents in those registers are 0x00000000 what ever the input may be.

Thanks

But the code you posted is meaningless.

There will not be any value in AD0DR2 unless you request that the ADC should perform a conversion of that channel. Where are your code that requests a read of analog channel 2?

You can't write code that expects that the "DONE" bit of AD0DR2 should be set unless you have first ordered a conversion for that channel.

You do:

AD0CR  |= 0x01000000;

but that will not convert a lot of channels unless you run full hardware conversion mode.

Hi

How to set the hardware conversion mode ? The thing is i need to convert two different analog input to digital simultaneously.

Thanks

What part of the user manual text is it that you do not understand?

You feel the text is unclear? What part of it?

select bit in ADCR Selects which of the AD0.7:0/AD1.7:0 pins is (are) to be sampled and converted. For AD0, bit 0 selects Pin AD0.0, and bit 7 selects pin AD0.7. In software-controlled mode, only one of these bits should be 1. In hardware scan mode, any value containing 1 to 8
ones. All zeroes is equivalent to 0x01.

I am connecting two hardware to two different channels .Both the channel has to be monitored continuously and the data has to be extracted.

I am not clear in configuring the adc channel for multiple input .

Thanks

Easy. You either run an interrupt handler and have the ADC convert continuously. Then every second interrupt will be the first or second input.

Or you have to specifically select the first input. Start conversion. Wait for answer. Read out answer. Start second conversion. Wait for answer. Read out answer.

What is unclear, when the manual says that if software mode, you can only start conversion of one (1) input? And in hardware scan mode, you can set up any combination of up to 8 inputs and it will continuously scan the selected inputs?