Hello you all,
it is my second "post" on this forum.
Just after the first one I received an e-mail of welcome from Paul (Congratulations paul for what you are doing!!!), mail which invited me to not to limit me to small technical questions but to, first of all, describe in detail what I am trying to accomplish.
Then I am going to try to do that although my project is at a very vague stage and a textbook case with regard to banality, which risks to bother you profoundly ...
Originally I bought the teensy 3.6 to command leds ws2812 with the library OctoWs2811, dedicated to the family Teensy ...
But on the way I wondered by reading the specifications if it would be possible to do the "data logger" of my dreams to record the cerebral activity of my mice...
In other words : 8-16 channels , 12-16bits, 20-30kHz/channel, record on SD card, control by wifi or bluetooth... hum, hum...
You see it is quite simple, maybe utopian and perfectly uninteresting for you all...
Currently I record the EEG of my mice with an OBCI card (http://openbci.com/) of excellent quality, which works very well but which is limited to 250Hz by its design.
The best that I was able to do by modifying as much as I am capable, the firmware, was :
8 channels(canals); 2kHz / channel; 24bits; spi SD record only; bluetooth control.
It is there : https://github.com/yj-xxxiii/OpenBCI_2kHz
These limitations prevent me to record signals faster than the eeg, such as spikes emitted by neurons themselves... For that I need 20-30kHz approximately.
It raises the usual questions which we find on this forum (and nxp) and of which I began the reading:
ADC ; DMA ; SDio.
I already found to study :
- The data sheet K66P144M180SF5RMV2.pdf
- https://github.com/greiman/SdFat
- https://github.com/tni/teensy-samples/blob/master/SdFatSDIO_low_latency_logger.ino
- https://forum.pjrc.com/threads/43708-Teensy-3-6-Datalogging-at-10kHz
- https://forum.pjrc.com/threads/47977-High-sampling-rate-measurement-for-weak-electrish-fish
- https://forum.pjrc.com/threads/45993-Teensy-3-6-ADC-DMA-Question
- https://community.nxp.com/docs/DOC-104395
- https://www.nxp.com/docs/en/application-note/AN4590.pdf
- SaileNav and Donziboy2
- ...
Thus my question is: do you believe that it is possible or a lost cause?
You should know also that I am not a good programmer but a simple biologist and that for example, I do not understand the "while(1)" in the "loop" of the program of Donziboy2 (04-15-2017, 01:43 PM) .
(does it exist a kind of "watch dog" which interrupts this infinit loop while(1)? ) I searched on the web but found nothing clear.
But I am very motivated ...
Thank's in advance for any advice.
Sincerely Yannick.
it is my second "post" on this forum.
Just after the first one I received an e-mail of welcome from Paul (Congratulations paul for what you are doing!!!), mail which invited me to not to limit me to small technical questions but to, first of all, describe in detail what I am trying to accomplish.
Then I am going to try to do that although my project is at a very vague stage and a textbook case with regard to banality, which risks to bother you profoundly ...
Originally I bought the teensy 3.6 to command leds ws2812 with the library OctoWs2811, dedicated to the family Teensy ...
But on the way I wondered by reading the specifications if it would be possible to do the "data logger" of my dreams to record the cerebral activity of my mice...
In other words : 8-16 channels , 12-16bits, 20-30kHz/channel, record on SD card, control by wifi or bluetooth... hum, hum...
You see it is quite simple, maybe utopian and perfectly uninteresting for you all...
Currently I record the EEG of my mice with an OBCI card (http://openbci.com/) of excellent quality, which works very well but which is limited to 250Hz by its design.
The best that I was able to do by modifying as much as I am capable, the firmware, was :
8 channels(canals); 2kHz / channel; 24bits; spi SD record only; bluetooth control.
It is there : https://github.com/yj-xxxiii/OpenBCI_2kHz
These limitations prevent me to record signals faster than the eeg, such as spikes emitted by neurons themselves... For that I need 20-30kHz approximately.
It raises the usual questions which we find on this forum (and nxp) and of which I began the reading:
ADC ; DMA ; SDio.
I already found to study :
- The data sheet K66P144M180SF5RMV2.pdf
- https://github.com/greiman/SdFat
- https://github.com/tni/teensy-samples/blob/master/SdFatSDIO_low_latency_logger.ino
- https://forum.pjrc.com/threads/43708-Teensy-3-6-Datalogging-at-10kHz
- https://forum.pjrc.com/threads/47977-High-sampling-rate-measurement-for-weak-electrish-fish
- https://forum.pjrc.com/threads/45993-Teensy-3-6-ADC-DMA-Question
- https://community.nxp.com/docs/DOC-104395
- https://www.nxp.com/docs/en/application-note/AN4590.pdf
- SaileNav and Donziboy2
- ...
Thus my question is: do you believe that it is possible or a lost cause?
You should know also that I am not a good programmer but a simple biologist and that for example, I do not understand the "while(1)" in the "loop" of the program of Donziboy2 (04-15-2017, 01:43 PM) .
(does it exist a kind of "watch dog" which interrupts this infinit loop while(1)? ) I searched on the web but found nothing clear.
But I am very motivated ...
Thank's in advance for any advice.
Sincerely Yannick.