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That should work I guess? But i'm trying to solve this on board and/or making use of the software libraries to create filters. Don't know if it's possible to filter the noise away by software?

I...

Hello Guys!

We're busy with a project including audio and recording, we are using the Teensy 3.2 and the Audio Board with a 20W amplifier. We are using the microphone input (not de line in). to...

Any good suggestions? I'm using the LIS3DH at this moment. Alternatives?

The application would be a simple office chair, i just want to detect the slightest movements, how people sit on their cheir etc. So the application needs to measure a change between ±15 degrees.

Hi there!

I've started a new hobby project where I want to test different kind of accelerometers in combination with my teensy 3.1.
Now i've seen lots of guides of how to select a suitable...

Is there a reason why i can only log 64 seconds? I did a measurement of 5 minutes, but only the first 64 seconds has been measured.. It's the half of 128 byte and 1/8 from 512 byte
Is it even...

The 3.3V is the teensy's 3.3V output. With this divider, a range can be set from a certain voltage. Basically, the level shifter is a three-resistor voltage divider, where R2(30.9k) and R3(39.2k)...

I switch from ports often on my laptop, but i dont set the com port in the Arduino IDE, it switch automatically here... Don't know if that happens on every laptop?
The hex file is loaded into Teensy...

[QUOTE]Does anybody see an issue with reading the VUSB straight into a digital pin?[/QUOTE
Well, putting VUSB on a digital just give a "0" or a "1" in my opinion, digital pins can handle 5V,


...

Purpose of this board is to measure analog signals from two sensors, these signals are preamplified. There's an analog differential amplifier with the two sensor inputs (which also forms A-B signal),...

That actually sounds cool! I'm wired to an MicroUSB cable, haha. see my attachment of my developed protoboard which has been used for measurement (to give somewhat a impression :) )

Thanks for the effort Turtle9er, it seems to work as far I see now, especially the starttime.

It seems that float buf did the trick. It was an int, but i'm using floating numbers.

Future...

Thanks for explanations! :)

I've changed it now, and I am getting some results!
Although, for testing i'm using as input: "micros,1,2,3" instead of the sensor signals

The output in the text file are:

Time A-B A B...

That does more then the code I had and been busy with. So far i was testing with my idea, i only got zero's..

Although i'm now using your code, I got this:

Time,A-B,A,B
0,0,0,0
0,0,0,0...

Update:
(1) In the binarytosd part, there is a line 'block_t buf' which buffer is this? in the example of turtle9er, is not used something like block_t.... so I wonder... :)

The link u send me...

Question, I'm logging binary files now, but i expect to have zero's and one's. my logfile.bin gave me this:

KÁ«•? 5@~|a?”K—Ê�?kD...

I'll check it out! thanks for the link!

I'm going to try implementing the bintocsv part into my current code, as far I see, some adjustments are needed...

If I succeed to get it working...

Hi there!

While I was measuring with noisy ECG signals, I need something that take cares of filtering the measured signals.

I came across the following filter library:...

It should not be a problem to use this method. I have implemented your code, although i need to make use of bufferedwriter.h, but where can i find this? It is not available in the sdfat library tho?...

Ahhh so I actually had a -70000 bug, but because of the calculations it's -56,4.. sounds logical... and yes, it was only with ADC1



that is silly, but that happens everyone. I'll check your...

At this point it seems that i don't have problems anymore with -70000 values, i've been able to fix this issue. Although, as is shown in my log files, i was reading strange values at -56. And it...

I haven't been able to log my files to sd, i see a .bin format, for my purposes i want a .txt file.
I have changed the 'char binName[13] = FILE_BASE_NAME "000.bin";' to 'char binName[13] =...

Thanks for uploading your attempt!

I'm currently testing the code you've send me, although, when measuring, i get values like -70000 etc etc. after changing the 'int SDBuffer' to 'float SDBuffer'....

I'm looking forward for some code of yours, i'm continuing my work tomorrow, have to work right now. :)
I'll check your post tomorrow i quess :)

Thanks in advance!

I've been busy for a while now, and i got the array principle working. it isn't stable yet tho, i have samples between 1 and 2k samples/second. Does anyone have an idea how to get a stable...

Haven't been able to fix it yet with the arrays, i believe something like this possible


int cols = 4;
int rows = 100;
int[][] myArray = new int[cols][rows];

// Two nested loops allow us to...

Well, i'm using the following sensors: http://www.mouser.com/ProductDetail/Plessey-Semiconductors/PS25101/?qs=sGAEpiMZZMttKWgNLnZcJgErdsXOV7xh
These sensor measures the ECG values of a person. The...

I did change the analog read part the way you did, and so far it seems to work, although it still lacks on the sample rate(almost the same results as the attached log file).

I did indeed start two...

Hello!

I've been busy with measuring analog values. It's possible to measure the values, but somehow i don't know how to increase the sample rate, it's maybe a noob question, but i'm using a...

Ahhh, would be smart to post some pictures / links next time.. ghehe

The i2c adapter can be found in this link: http://www.robot-electronics.co.uk/htm/usb_i2c_tech.htm
schematics: 2085

there...

Nobody knows? :)

While i'm busy with my project for measuring ECG signals, there are some issues which came across.

I've managed to write 2 analog signals synchronous to the sdcard.

But at this very moment:...

Hi There!

I've been trying to connect my Teensy 3.1 to LabVIEW. Using the tool "Basic Serial Write and Read Modified.vi" in this post: https://decibel.ni.com/content/message/69017.

But I was...

For that my friend, is needed a Driven Right Leg circuit. Which i also have included within my design. It basically a ground plane with an inverted signal on the human body. For example: the sensors...

There are many opamp circuits available ofcourse, but the offset shall be less then 3.3V tho? Any schematic available?

I'm using an Plessey EPIC Sensor (PS25201). For measuring ECG signals. Those signals are very weak. The sensor itself generates approx. max ± 2.5V at the output.
i came across this solution:
...

I've read about the internal voltage (3.3V)?

But what about measuring signals above that reference? Let's asume my sensor signal is 2,5V, with an level shifter (3.3V for example) it's gonna be:...

I've been testing this circuit, but when my input is 2V for example, it halves it. ;) so that leaves me 1V at the output.

I'm measuring signals approx. 30-60mV. when that halves (15-30mV), it...

Do you know what location? is it those 2 pads, which can be cut? As far I see in this picture http://www.pjrc.com/teensy/schematic3.gif there are two pins (VUSB and VIN) and in between two pads which...

ADC0_DM0(A11) and ADC0_DP0 (A10) are on the same 'ADC0' channel, So that means that they can't measure synchronous? The 12-bit ADC's A2 and A3 are also well enough. But it would be nice if it was...

Hi there,

I've been watching the schematics and specification/datasheet from the Teensy 3.1, and I have two questions about the voltage output and ADC Input

Q1
The USB input gives a 5V Out, I...

I'm understanding that I can only select one function at a time, but in your post you said "Pins A2 and A3 are particulary useful for the synchronous measurement". Those pins are, as far I see 12...

Hi there,

Maybe a dumb question, i've been watching this pin layout from the Teensy 3.1 (see link) http://www.pjrc.com/teensy/card5a_rev5.pdf
In the datasheet of the processor are the pins...