[beagleboard] BBB Data Aggregation Unit using external ADC
Hi everyone, I am new to the world of using MCUs and am looking for some assistance on a project that I am currently working on. To sum things up quickly, I am building a data aggregation unit that can convert analog voltage readings to digital values that is to be stored on a USB or SD card. The DAU will collect 3 types of signals, a buffer signal, clipped signal, and a signal passed through a LPF. In the end, the data should be stored as either a MatLab file or .xml file. However, I am facing a few road blocks relating to my design. 1.) I need to use a 24 bit ADC for high resolution purposes based on design requirements that were just given to me as I will be collecting data from .1mV to 50V and it has to have a high sample speed rate. Has anyone connected an external ADC to the BBB? If so, what was the brand of your external ADC? How did you connect the ADC to the BBB? (It'd be greatly appreciated to be able to see a design). 2.) If you have had a similar project to this, was wondering how you went about it. Any advice would be greatly appreciated. As I said before, all of this is very new to me. So thank you for taking the time to help me out. Chelsea -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: BBB Data Aggregation Unit using external ADC
Hi John, Thanks for getting back to me. I was actually looking at that same ADC converter as you posted in your reply. Just looking for some clarification on a few things. What type of error would a simple resistor divider introduce into the system? I am currently using a cascaded inverting op amp system. Not really sure if this will scale the input voltage to a level that is compatible with my ADC. The circuit diagram looks like this: [image: Inline image 1] Looking forward to your reply, Chels On Thursday, December 3, 2015 at 5:07:41 PM UTC-5, Chelsea Orefice wrote: > > Hi everyone, > > I am new to the world of using MCUs and am looking for some assistance on > a project that I am currently working on. To sum things up quickly, I am > building a data aggregation unit that can convert analog voltage readings > to digital values that is to be stored on a USB or SD card. The DAU will > collect 3 types of signals, a buffer signal, clipped signal, and a signal > passed through a LPF. In the end, the data should be stored as either a > MatLab file or .xml file. However, I am facing a few road blocks relating > to my design. > > 1.) I need to use a 24 bit ADC for high resolution purposes based on > design requirements that were just given to me as I will be collecting data > from .1mV to 50V and it has to have a high sample speed rate. Has anyone > connected an external ADC to the BBB? If so, what was the brand of your > external ADC? How did you connect the ADC to the BBB? (It'd be greatly > appreciated to be able to see a design). > > 2.) If you have had a similar project to this, was wondering how you went > about it. Any advice would be greatly appreciated. > > > As I said before, all of this is very new to me. So thank you for taking > the time to help me out. > > Chelsea > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: Private message regarding: [beagleboard] BBB Data Aggregation Unit using external ADC
Hi John, Just wanted to say thank you for really helping me with this. It has been a struggle for me and my team to get help from different resources at school as well as our liaisons where we are getting our design requirements from. (This is our senior engineering project.) I am having still a little difficulty in understanding how the circuitry I shared with you may give me a single input instead of differential that the ADC requires.I attached the actual design of the system, so if you could help me understand how it won't work it'd be much appreciated. Also, may you tell me your background in relation to all of this? You are very knowledgeable in this area, and when I relay some of this information to my team I would like to share from whom I received this information from. Sincerely, Chelsea On Thu, Dec 3, 2015 at 7:01 PM, John Syne wrote: > Hi Chelsea, > > I have cc beagleboard because someone else might learn from this > discussion. Looking at the link you provided, it won’t work because ADS1278 > requires a differential input. Look at page 39 for circuits that will work > for you. > > Regards, > John > > > > > On Dec 3, 2015, at 3:52 PM, Chelsea Orefice wrote: > > My apologies. Please let me know if this link works. (You will need to > just copy and paste in search bar). If that doesn't work I will send it as > an attachment. Will also look at the diagram as well. > > http://cnx.org/resources/72628d36f0c24bc80ff94e5c0bf6df2b27a > 86751/opamp4.png > > Thanks again, > Chelsea > > On Thursday, December 3, 2015 at 6:46:49 PM UTC-5, john3909 wrote: >> >> Look at page 39 for a suitable input circuit. >> >> Regards, >> John >> >> >> >> >> On Dec 3, 2015, at 3:03 PM, Chelsea Orefice wrote: >> >> Hi John, >> >> Thanks for getting back to me. I was actually looking at that same ADC >> converter as you posted in your reply. Just looking for some clarification >> on a few things. What type of error would a simple resistor divider >> introduce into the system? I am currently using a cascaded inverting op >> amp system. Not really sure if this will scale the input voltage to a level >> that is compatible with my ADC. >> >> The circuit diagram looks like this: >> [image: Inline image 1] >> >> Looking forward to your reply, >> Chels >> >> On Thursday, December 3, 2015 at 5:07:41 PM UTC-5, Chelsea Orefice wrote: >>> >>> Hi everyone, >>> >>> I am new to the world of using MCUs and am looking for some assistance >>> on a project that I am currently working on. To sum things up quickly, I am >>> building a data aggregation unit that can convert analog voltage readings >>> to digital values that is to be stored on a USB or SD card. The DAU will >>> collect 3 types of signals, a buffer signal, clipped signal, and a signal >>> passed through a LPF. In the end, the data should be stored as either a >>> MatLab file or .xml file. However, I am facing a few road blocks relating >>> to my design. >>> >>> 1.) I need to use a 24 bit ADC for high resolution purposes based on >>> design requirements that were just given to me as I will be collecting data >>> from .1mV to 50V and it has to have a high sample speed rate. Has anyone >>> connected an external ADC to the BBB? If so, what was the brand of your >>> external ADC? How did you connect the ADC to the BBB? (It'd be greatly >>> appreciated to be able to see a design). >>> >>> 2.) If you have had a similar project to this, was wondering how you >>> went about it. Any advice would be greatly appreciated. >>> >>> >>> As I said before, all of this is very new to me. So thank you for taking >>> the time to help me out. >>> >>> Chelsea >>> >>> >>> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to beagleboard...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> >> >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: Private message regarding: [beagleboard] BBB Data Aggregation Unit using external ADC
Also in the attachment, the parts labeled MCU will now be ADC. (Sorry about that.) On Thu, Dec 3, 2015 at 8:57 PM, Chelsea Orefice wrote: > Hi John, > > Just wanted to say thank you for really helping me with this. It has been > a struggle for me and my team to get help from different resources at > school as well as our liaisons where we are getting our design requirements > from. (This is our senior engineering project.) > > I am having still a little difficulty in understanding how the circuitry I > shared with you may give me a single input instead of differential that the > ADC requires.I attached the actual design of the system, so if you could > help me understand how it won't work it'd be much appreciated. > > Also, may you tell me your background in relation to all of this? You are > very knowledgeable in this area, and when I relay some of this information > to my team I would like to share from whom I received this information > from. > > > Sincerely, > Chelsea > > On Thu, Dec 3, 2015 at 7:01 PM, John Syne wrote: > >> Hi Chelsea, >> >> I have cc beagleboard because someone else might learn from this >> discussion. Looking at the link you provided, it won’t work because ADS1278 >> requires a differential input. Look at page 39 for circuits that will work >> for you. >> >> Regards, >> John >> >> >> >> >> On Dec 3, 2015, at 3:52 PM, Chelsea Orefice wrote: >> >> My apologies. Please let me know if this link works. (You will need to >> just copy and paste in search bar). If that doesn't work I will send it as >> an attachment. Will also look at the diagram as well. >> >> http://cnx.org/resources/72628d36f0c24bc80ff94e5c0bf6df2b27a >> 86751/opamp4.png >> >> Thanks again, >> Chelsea >> >> On Thursday, December 3, 2015 at 6:46:49 PM UTC-5, john3909 wrote: >>> >>> Look at page 39 for a suitable input circuit. >>> >>> Regards, >>> John >>> >>> >>> >>> >>> On Dec 3, 2015, at 3:03 PM, Chelsea Orefice wrote: >>> >>> Hi John, >>> >>> Thanks for getting back to me. I was actually looking at that same ADC >>> converter as you posted in your reply. Just looking for some clarification >>> on a few things. What type of error would a simple resistor divider >>> introduce into the system? I am currently using a cascaded inverting op >>> amp system. Not really sure if this will scale the input voltage to a level >>> that is compatible with my ADC. >>> >>> The circuit diagram looks like this: >>> [image: Inline image 1] >>> >>> Looking forward to your reply, >>> Chels >>> >>> On Thursday, December 3, 2015 at 5:07:41 PM UTC-5, Chelsea Orefice wrote: >>>> >>>> Hi everyone, >>>> >>>> I am new to the world of using MCUs and am looking for some assistance >>>> on a project that I am currently working on. To sum things up quickly, I am >>>> building a data aggregation unit that can convert analog voltage readings >>>> to digital values that is to be stored on a USB or SD card. The DAU will >>>> collect 3 types of signals, a buffer signal, clipped signal, and a signal >>>> passed through a LPF. In the end, the data should be stored as either a >>>> MatLab file or .xml file. However, I am facing a few road blocks relating >>>> to my design. >>>> >>>> 1.) I need to use a 24 bit ADC for high resolution purposes based on >>>> design requirements that were just given to me as I will be collecting data >>>> from .1mV to 50V and it has to have a high sample speed rate. Has anyone >>>> connected an external ADC to the BBB? If so, what was the brand of your >>>> external ADC? How did you connect the ADC to the BBB? (It'd be greatly >>>> appreciated to be able to see a design). >>>> >>>> 2.) If you have had a similar project to this, was wondering how you >>>> went about it. Any advice would be greatly appreciated. >>>> >>>> >>>> As I said before, all of this is very new to me. So thank you for >>>> taking the time to help me out. >>>> >>>> Chelsea >>>> >>>> >>>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to beagleboard...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: Private message regarding: [beagleboard] BBB Data Aggregation Unit using external ADC
Hi John, These are very helpful links. I was wondering if there was an online document on all functions that I can code BBB in either in C, C++, python, etc. Thanks, Chelsea On Thu, Dec 3, 2015 at 11:12 PM, John Syne wrote: > Hi Chelsea, > > Here are some reference I have found helpful: > > > http://www.analog.com/library/analogdialogue/archives/39-05/op_amp_applications_handbook.html > > http://www.analog.com/library/analogDialogue/archives/39-06/data_conversion_handbook.html > > Regards, > John > > > > > On Dec 3, 2015, at 5:57 PM, Chelsea Orefice wrote: > > Hi John, > > Just wanted to say thank you for really helping me with this. It has been > a struggle for me and my team to get help from different resources at > school as well as our liaisons where we are getting our design requirements > from. (This is our senior engineering project.) > > I am having still a little difficulty in understanding how the circuitry I > shared with you may give me a single input instead of differential that the > ADC requires.I attached the actual design of the system, so if you could > help me understand how it won't work it'd be much appreciated. > > Also, may you tell me your background in relation to all of this? You are > very knowledgeable in this area, and when I relay some of this information > to my team I would like to share from whom I received this information > from. > > > Sincerely, > Chelsea > > On Thu, Dec 3, 2015 at 7:01 PM, John Syne wrote: > >> Hi Chelsea, >> >> I have cc beagleboard because someone else might learn from this >> discussion. Looking at the link you provided, it won’t work because ADS1278 >> requires a differential input. Look at page 39 for circuits that will work >> for you. >> >> Regards, >> John >> >> >> >> >> On Dec 3, 2015, at 3:52 PM, Chelsea Orefice wrote: >> >> My apologies. Please let me know if this link works. (You will need to >> just copy and paste in search bar). If that doesn't work I will send it as >> an attachment. Will also look at the diagram as well. >> >> http://cnx.org/resources/72628d36f0c24bc80ff94e5c0bf6df2b27a >> 86751/opamp4.png >> >> Thanks again, >> Chelsea >> >> On Thursday, December 3, 2015 at 6:46:49 PM UTC-5, john3909 wrote: >>> >>> Look at page 39 for a suitable input circuit. >>> >>> Regards, >>> John >>> >>> >>> >>> >>> On Dec 3, 2015, at 3:03 PM, Chelsea Orefice wrote: >>> >>> Hi John, >>> >>> Thanks for getting back to me. I was actually looking at that same ADC >>> converter as you posted in your reply. Just looking for some clarification >>> on a few things. What type of error would a simple resistor divider >>> introduce into the system? I am currently using a cascaded inverting op >>> amp system. Not really sure if this will scale the input voltage to a level >>> that is compatible with my ADC. >>> >>> The circuit diagram looks like this: >>> [image: Inline image 1] >>> >>> Looking forward to your reply, >>> Chels >>> >>> On Thursday, December 3, 2015 at 5:07:41 PM UTC-5, Chelsea Orefice wrote: >>>> >>>> Hi everyone, >>>> >>>> I am new to the world of using MCUs and am looking for some assistance >>>> on a project that I am currently working on. To sum things up quickly, I am >>>> building a data aggregation unit that can convert analog voltage readings >>>> to digital values that is to be stored on a USB or SD card. The DAU will >>>> collect 3 types of signals, a buffer signal, clipped signal, and a signal >>>> passed through a LPF. In the end, the data should be stored as either a >>>> MatLab file or .xml file. However, I am facing a few road blocks relating >>>> to my design. >>>> >>>> 1.) I need to use a 24 bit ADC for high resolution purposes based on >>>> design requirements that were just given to me as I will be collecting data >>>> from .1mV to 50V and it has to have a high sample speed rate. Has anyone >>>> connected an external ADC to the BBB? If so, what was the brand of your >>>> external ADC? How did you connect the ADC to the BBB? (It'd be greatly >>>> appreciated to be able to see a design). >>>> >>>> 2.) If you have had a similar project to this, was wondering how you >>>> went about it. Any advice would be greatly appreciated. >>>&g
[beagleboard] Read voltage from ADC using an external power supply
Hi All,
I have a new BBB. I'm trying to read voltages from a DC power supply. I'm
having trouble doing so. I connected the output from the power supply to
AIN0, and the ground from the power supply to the ADC_GND, and tried to run
the code, but the voltages that I'm reading doesn't make sense.
So I went back to the basic, and just ran the code without plugging
anything in, and yet the voltage value I'm printing says 1.6 instead of 0.
Below shows the code, which I got from adafruit. I'm aware that I'm not
supposed to connect BBB ADC to anything above 1.8V or below 0V, which I
don't believe I have.
import Adafruit_BBIO.ADC as ADC
> ADC.setup()
> value = ADC.read("P9_40")
> voltage = value * 1.8
> print (voltage)
https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/adc
I've also been reading somewhere that I may have to enable the ADC before I
can read it??
Help?
Thanks.
--
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[beagleboard] Re: Read voltage from ADC using an external power supply
Thank you all for helping out. The clarification is much appreciated. I am also wondering if there is anyway to reset the bbb without using an sd card? I was working on trying to enable the SPI on the bbb, but now think I might have damaged something since it's not able to be detected by my pc... -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
