noisy ADC question

Started by aaajbell in LPC200011 years ago 11 replies

Hello, I'm trying to input a couple 10-bit analog signals to 2 ADC channels on a LPC2103. The signals are generated very simply with 10K...

Hello, I'm trying to input a couple 10-bit analog signals to 2 ADC channels on a LPC2103. The signals are generated very simply with 10K pots connected across the board's ground and the regulated 3.3 volt DC. The center or swipe connection on each pot is connected directly into an ADC channel. The board itself is powered with a regulated 4.5 volt DC power supply. The readings are very...


PWM Conflicts with ADC on LPC2148

Started by "Ben...@yahoo.com [lpc2000]" in LPC20004 years ago 1 reply

I am using the LPC2148 with a 12MHz crystal using a 5 multiplier to have 60MHz CCLK. PCLK running at same frequency as CCLK. I had some working...

I am using the LPC2148 with a 12MHz crystal using a 5 multiplier to have 60MHz CCLK. PCLK running at same frequency as CCLK. I had some working software triggered ADC code. When I added a PWM output with a match interrupt, the ADC always returns 0 (the PWM output is working correctly) I can't figure out why this is happening. Any help would be appreciated Here is a link to the PastBin for the co...


LPC2148 ADC input and bootloader questions

Started by Aalt Lokhorst in LPC200012 years ago 12 replies

Dear Readers, I like to use the LPC2148 for a project but have some questions. --Question 1-- In the datasheets there is a note for...

Dear Readers, I like to use the LPC2148 for a project but have some questions. --Question 1-- In the datasheets there is a note for ADC-input regarding voltages above VDD (just in case the pins are used as 5V tolerant input) For instance if P0.5/ADC0.7 and P0.4/ADC0.6 are used as ADC input then a voltage greater than 3.3V on ADC0.7 will disturb a measurement of ADC0.6. Now the que...


LPC17xx ADC burst mode vs interrupt mode

Started by Jean-Sebastien Stoezel in LPC20007 years ago 9 replies
ADC

Hi: I would like to identify the pros and cons of using the ADC of an LPC17xx in burst vs interrupt mode. The end application I'm working on...

Hi: I would like to identify the pros and cons of using the ADC of an LPC17xx in burst vs interrupt mode. The end application I'm working on is a typical control system, analog channels are sampled at a fixed rate, then processed, and eventually outputs are updated. I see at least 2 ways of implementing this: - In interrupt mode, a timer would start the ADC conversions and an interrupt ...


LPC2000 ADC/DAC

Started by jdauchot in LPC200011 years ago 7 replies

Hi All Can someone explain why NXP has liminted the bit resolution to 10 bits on the ADC and DAC in their chips? Regards Jean-Jacques

Hi All Can someone explain why NXP has liminted the bit resolution to 10 bits on the ADC and DAC in their chips? Regards Jean-Jacques


LPC2148 ADC

Started by kaushikraja1986 in LPC20009 years ago

Hii guys.I'm facing a problem with my ADC code on a development board of LPC2148.my reference voltage is internal and it is equal to Vcc=3.45V..I...

Hii guys.I'm facing a problem with my ADC code on a development board of LPC2148.my reference voltage is internal and it is equal to Vcc=3.45V..I have checked it.The input is at pin 13 i.e., AD0.1. My clock settings are as follows pclk -> 60MHz VPB clock -> 60MHz ADC clock -> 4MHz the major problem I'm facing now is that even the output value for a constant analog supply say 3v is not coming


LPC2888 Dual ADC Problem

Started by clch...@radiantech.com.tw in LPC20008 years ago
ADC

Hi ALL, We have a using problem on LPC2888 Dual ADC. We can not get sampling data from any register ( LR32IN4 etc) of SAI4 by sample code of...

Hi ALL, We have a using problem on LPC2888 Dual ADC. We can not get sampling data from any register ( LR32IN4 etc) of SAI4 by sample code of UM. Our condition is shown below: We use LPC2800 EVALUATION BOARD. The setup of CGU is ok for 8kHz sampling rate. The interrupt subroutine of ADC works well only time tag. The output data of SAI4 have a description table as below. ENTIME...


ADC programming

Started by supriya albal in LPC20009 years ago 17 replies

I have done ADC programming. I can display hex and decimal values of result on LCD. Can anyone guide me how to show exactly 1.1V for applied...

I have done ADC programming. I can display hex and decimal values of result on LCD. Can anyone guide me how to show exactly 1.1V for applied voltage of 1.1V.? Does anyone have code for the same?


about i2s of LPC2378

Started by sukhdeep singh in LPC20009 years ago

hi, =A0=A0=A0=A0=A0 i am interfacing LPC2378 with 24 bit adc. adc is operating = in slave mode. now i want operate lpc2378 in master mode. what...

hi, =A0=A0=A0=A0=A0 i am interfacing LPC2378 with 24 bit adc. adc is operating = in slave mode. now i want operate lpc2378 in master mode. what should i=A0u= se in programming=A0I2SDAI or I2SDAO of i2s,second thing is that i want to = pick data of left and right channel of adc. how can i set the number of FIF= O registers. where will be the data of left and right channel in FIFO. what= shou...


ADC Sample

Started by lokesh_17 in LPC200013 years ago 1 reply

can anybody give the sample code for adc with interrupt mode for lpc2124. thanks, Lokesh.S

can anybody give the sample code for adc with interrupt mode for lpc2124. thanks, Lokesh.S


external adc interfacing to lpc2148

Started by Soori in LPC20009 years ago 1 reply

hi, i want to interface adc externally to lpc2148.plz any one help me. thanks & regards, suresh ------------------------------------

hi, i want to interface adc externally to lpc2148.plz any one help me. thanks & regards, suresh ------------------------------------


ADC Interface

Started by samiehg in LPC200011 years ago

Hi Has anybody interfaced with Texas instrument ADC (TLC3574/TLC3578/TLC2574/TLC2578) ? I am having problems interfacing it with the SPI...

Hi Has anybody interfaced with Texas instrument ADC (TLC3574/TLC3578/TLC2574/TLC2578) ? I am having problems interfacing it with the SPI module. I have posted some questions to their tech support, but thought of asking if anybody else has done it before who would be willing to share their knowledge. Thanks Samie


LPC2888 interfacing with high speed ADC.

Started by Prashant A in LPC20009 years ago 3 replies

Hi, The clarification that i have is, would it be possible to interface an ADC (10 or 12 bit) to the GPIO pins corresponding to the LCD...

Hi, The clarification that i have is, would it be possible to interface an ADC (10 or 12 bit) to the GPIO pins corresponding to the LCD interface. The data sampling rate would be around 5 MHz. With regards, Prashant


LPC175x adc problems

Started by "M. Manca" in LPC20008 years ago
ADC

I am experiencing problems with adc of LPC175x mcu. Seems that if the mcu works with the internal oscillator without the PLL0 it reads a...

I am experiencing problems with adc of LPC175x mcu. Seems that if the mcu works with the internal oscillator without the PLL0 it reads a different value then with the internal oscillator with the PLL enabled. Seems also that the problem is present using the external oscillator with a 12MHz crystal without the PLL0 enabled. I read that adc clock maximum frequency is 13MHz so I suppose it can ...


adc overrun

Started by dnsu2 in LPC20007 years ago 4 replies
ADC

Could somebody enlighten me over the ADC overrun issue on LPC2468? I am using timer1 0.5mS interrupt to set AD0 burst mode, then use AD0.3 as...

Could somebody enlighten me over the ADC overrun issue on LPC2468? I am using timer1 0.5mS interrupt to set AD0 burst mode, then use AD0.3 as interrupt. the AD0 INT Service routine clears the burst mode on the first line of code. the program can run sometime for 3-4 hours and sometime for 1-2 hours, then overrun happens. The ADC registers are read to clear the overrun bit, and data discard...


Re: LPC2144 EEPROM & ADC PROBLEM

Started by Alexandre Kremer in LPC200011 years ago

Hi Ok. Just to understand your tests. With the SAME firmware, if you turn the system on with no analog voltage on ADC the flash memory area...

Hi Ok. Just to understand your tests. With the SAME firmware, if you turn the system on with no analog voltage on ADC the flash memory area used as EEPROM remains intact, and when you turn the system on with the described analog voltage on the ADC pin, the flash area is erased? Could you run it with debug on and check the memory on both cases, or it just happens when the power is sup...


proteus LPC2103 adc result stuck to 0

Started by alex...@freemail.gr in LPC20008 years ago 4 replies

I have tried to use the ADC converter in LPC2103 and everything is set up correctly but the adc converter result is always 0, the keil...

I have tried to use the ADC converter in LPC2103 and everything is set up correctly but the adc converter result is always 0, the keil debugger shows that the code works correctly. I have also tried with burst mode and different inputs but the result is still 0, the result and overrun bits work fine. I have also tried the code with lpc2131 and works fine there (with different pinsel) In pro...


power down input protection for LPC213x ADC

Started by Kevin Lynch in LPC200010 years ago

Hi Folks ? I have a question about power down input protection for the ADC circuit for the LPC213x processors - does the LPC213x have a JFET or...

Hi Folks ? I have a question about power down input protection for the ADC circuit for the LPC213x processors - does the LPC213x have a JFET or similar protection for the input ports of the ADC circuit to isolate the circuit from any external voltage when the power is down? I?m working on an existing LPC2138 based product that uses a 3V lithium battery to back up the RTC circuit (Vbat) ...


Conflict among the chanels of ADC on LPC2214

Started by hbao...@yahoo.com in LPC200010 years ago 3 replies

hello, I write a funtion to read adc on LPC2214.but sometime the result of that function mix between the result of chanel 1 and chanel 2 of...

hello, I write a funtion to read adc on LPC2214.but sometime the result of that function mix between the result of chanel 1 and chanel 2 of ADC ex on AIN0 is 2.5v the result should be about 775 on AIN1 is 3V the result should be about 930 but sometime I read on chanel0 on pin AIN0 ,the result of it is 930 how can i solve that problem here is that function; unsigned long int read_a...


LPC2129 ADC

Started by firegenie1980 in LPC200014 years ago 3 replies

Hi, Im using the onboard ADC for a project I am working on. However I seem to be getting some strange values and it isnt...

Hi, Im using the onboard ADC for a project I am working on. However I seem to be getting some strange values and it isnt acting as I expect it to. Two things mainly: One, when I take a voltage input of a constant voltage (0.5 * 3.3V) I get f