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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 think it's a strange behavior because on the power supply I don't see any noise. Only when we use a...

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 record voices. The microphone we use is a Electret Microphone from Adafruit, also we can connect...

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 accelerometer. But i'm getting stuck on the sensitivity part. I see different kind of notations, such...

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 possible to measure longer then 10 minutes for example? Also, I have added a button function with...

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) forms a voltage divider from 3V3 input. This can be seen as a voltage between the 3V3 input and...

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 application tho? It will upload anyway, atleast, i havent interfaced any problems with that....

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), the differential signal can be measured by Teensy aswell, with the use of levelshifters. Also...

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 improvements will be the replacement of inputs (record and stop record) with buttons. For now, I'll tweak...

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 1240771400 1073741824 1077936128 1082130432 1240803400 1073741824 1077936128 1082130432 1240835400 1073741824...

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 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 0,0,0,0 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 provides an analogbinlogger made for arduino uno, it's a lot of work to get it worked with Teensy as...

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 @~|a?4K¬¼Š?ëzû?~|a?Ô$K´@‹?óþû?~|a?t4KL&‹?#Êû?®Ga?DK‰_…?Èö?~|a?´SKºbx?œïì?~|a?TcK$Ík?9¿æ?N±a?ôrKöNo?"€è?N±a?”‚KˆJu?S˜ë?æa?4’Kæ“q?š¢é?N±a?Ô¡K¾Ob?† â?N±a?t±Kê3X...

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 properly, I will make a basic template for people who want to measure analog signals as well and trying to...

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: http://jeroendoggen.github.io/Arduino-signal-filtering-library/ It seems pretty easy to create a filter with this... It sounds...

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? Or am i using the wrong sdfat lib? >.< The one i'm using is the 'SdFatBeta20121203'? I've...

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 update when it's ready! btw.... in the example of synchronizedmeasurement there was a error aswell for...

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 seems to behave at every fifth value. @turtle9er i will check up your code with binary to text next...

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] = FILE_BASE_NAME "000.txt";' on my sd card, i see now .txt files, but empty... I have changed the...

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 got some values. also, had to change this: void timerCallback0(){ result =...

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 measurement where i can get like 250 samples / second? By the way... it is not possible to put a void...

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 visit every spot in a 2D array. // For every column I, visit every row J. for (int i = 0; i < cols; i++)...

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 output enters an gain amplifier (x1 or x10), the output is connected to a levelshifter which is...

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 measurements, because i was using serial or SD. when using one of them, it only start one...

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 combination of the following libraries - SDfat (for logging to SDcard) - RTC - Teensy Synchronous...

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: there are two sensor outputs, which both enters the first stage (S1_GAI or S2_GAI). The outsignal (S1_GAO or...

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: a) I'm using an usb-to-I2C adapter which is connected to my Teensy and digital potentiometer...

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 wondering if it's actually possible to control the Teensy's I²C or serial output? Or do i need to use a...

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 output is 1V, the Driven Right Leg output is -1V to compensate the noise ratio etc. True...

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: Schematic: Simulation: Output is still divided by approx a half but in the µC could amplify the...

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: 3.3+2.5 = 5.8V. Can the ADC deal with that? And what happens to an adc when the input reaches their...

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 makes it harder to "sense" these low voltages.

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 can be cut. but as far i see there is no protection? only the 500mA fuse. The sensor can...

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 possible to measure 2 signals synchronous with 16-bit. Maybe in the future.. :) Is there an...

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 figured out that there is a 5V output line.. actually two, but one out(VIN) can be used for external...

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 bits channels, what about the 16-bit channels? I thought that those two pins could used synchronous...

Teensy 3.1: ADC PINS / 16-Bits mode 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 located on pin 9 and 10 (PGA0_DM/ADC0_DM0/ADC1_DM3 (9) and...