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Hi All,

I am working on a project that includes a webserver and I plan to implement both webpage serving and file serving primarily for remote datafile download.

Thus far I have been using the...

Hi Shawn, interested in coming along but I'm in NSW Australia so very offset timezone. What time of your day do you typically do this?

Many thanks Christof !! exactly what I am looking for at the moment.

BadMisterFrosty I am currently doing something very similar to what you are planning. I am using an ISR triggered by the ADC...

The Encoder example available from the Arduino list works just fine, is this using your library?

If so, there is obviously something in my project screwing things up.... will need to dig around...

Hi mjs513

I'm having a curious issue with this library when definint phase A as pin1 and phase B as pin 3 on a Teensy 4.1.

The signal and phase offset looks good on the scope (there is...

Hi Chris O

I am still getting my head around (very slowly) the nomenclature and the different labelling levels.

In the schematic you linked to, what is the 'port' AD_B1 ?

I need to map my...

This is roughly the code I'll try out this evening


#define IMXRT_GPIO6_DIRECT (*(volatile uint32_t *)0x42000000)
// read in raw values from single port GPIO6
register uint32_t rawdata...

Found this thread which looks very useful, I'll convert my code and report back on the new time consumed.

https://forum.pjrc.com/threads/61615-Teensy-4-1-Storing-the-value-of-18-pins-input-quickly

I have an application capturing both analog and digital data up to a rate of 128ksps.

At the moment the ISR is taking too much time and making the 128ksps rate unviable for streaming purposes.
...

I've determined that at the 128ksps rate, it is basically running out of time for all processes to complete adequately and all hell brakes loose.

I added the head and tail indexes to the stream...

Hi Shawn,

After further testing I believe my issues are simply running out of processing time in between my interrupts at 128kHz.

I added debugging information to my data stream (going over UDP...

Hi Shawn, sorry but have not checked that response specifically, however I do believe the issue was caused by the circular buffer being corrupted.

I have implemented my own very lightweight...

Hi Shawn,

Will give it a go tonight, many thanks.

This relates to a data capture and streaming application, where at its fastest (currently) a combination of ADC results, time stamp, encoder count and input byte are written to a buffer in the ADC...

The packet rate has been tried at various multiples of the sample rate ie 10x, 100x and 200x without any change.

I've determined the issue is with the data source getting corrupted not the packet...

I have an application where I need to stream 128k packets per second of 18bytes over 100Mbit ethernet.

I am able to succeed at 64ksps using QNEthernet and the function:
...

I am using the hardware encoder library which is working well thus far.

I have an application that would benefit greatly from the measurement of the phase angle over time ie the phase shift...

Hi KenHahn, That is a great suggestion and easy one for me to implement !

I currently have a Schottky diode in series with the 5V input to prevent any chance of the USB supply feeding the rest of...

Ok tried 528MHz and total current draw is down to 262mA on the 5V feed with ethernet running.

CPU internal temp looks to be down to just under 54degC, down from about 62 so that is significant.
...

So I put some stops in my setup code to try and work out what was chewing up the extra current.

- setup pin mapping and wait for serial port to initialise : 161mA
- allow external ADC to init and...

It looks as though the teensy is using about 100mA itself initially (total current draw 180mA) but after a little while total current draw on 5V input goes to 265mA.

I'll isolate some functions...

That 80mA is external devices running off the Teensy 3.3V, I have not measured the teensy current draw as yet.

I am using the std Teensy 4.1 board mounted onto my custom board so thermal...

I have a custom board with numerous peripherals connected to the Teensy 4.1 and some of them being supplied by the on-board 3.3V reg and they are using 80mA (ADC, 16MHz clock, line driver and...

I've done some work to analyse the time taken for code within the ISR and nothing in there is causing the blowouts/large jitter.

Total ISR execution time: 375ns (av) 445ns (max) 372ns (min) 6.6ns...

Thanks KurtE, much appreciated.

It is much improved now, still some smaller time blowouts occuring however these may be caused by something I am doing in the ISR....

Hi all

I am working on a high speed logging type device with an external ADC connected by SPI to the T4.1.

There is a single ISR that is triggered by the ADC data ready line going low, this is...

Thanks all,

Very useful information.

I have a 16MByte ram buffer so should be covered for SD write delays..

Will have a play with this using various sized 'chunks' to see what effect that...

Hi Defragster, that is awesome news!

I'll upgrade my TeensyDuino to latest today and revise what I am getting.

Many thanks for your feedback.

Hi All

I have an application where I am capturing 4 channels of 24bit Analog at 128ksps.

The T4.1 I am using has 16MBytes of QSPI ram installed and I use this as a buffer for batch mode but...

Hi All

I have a project where I need to generate a number of synthesised signals, those being simulated Quadrature encoder out up to about 30MHz (count rate) and a wave form of Sine, Sawtooth and...

Thanks all, very useful input.

I'm currently running a 4ch 24bit ADC from TI with a sample rate of 32KHz and I'm using an SPI clock of 16MHz and this is quite adequate. I plan to run a similar...

Hi All,

I'm trying to find the highest clock freq I can run on the T4.1. Is this determined by the hardware or limitations in the SPI library?

I'm a bit bamboozled as to where I should be...

This is what I am using to get to dB after the FFT has been calculated (note I am using a floating point FFT here)


for(j=0;j<samples/2;j++){
vReal[j] /= (double)samples/2.0; // bring...

This seems to have worked:

NVIC_SET_PRIORITY(IRQ_GPIO1_16_31, 16);

Not sure how that group relates to what's on the schematic but it does the trick....

I am trying to apply this to my code on a Teensy4.1 with an external ADC with an interrupt on data ready.

Input is to pin 24 but the port naming convention seems to be very different to the Teensy...

Maybe have a look at this https://www.ftdichip.com/old2020/Support/Utilities.htm#ESD4

You would need to use one of the EVE displays, but you can interface to these easily it seems.

Hi Paul,

Tried that and there was an improvement for my standard DAQ capture from 856kB/s up to 1018kB/s.

Interested to know if others are getting USB MSC file write speeds higher than this...

Hi defragster, will continue to search, nothing found yet.

Any pointers on where to look for the USB host write buffer settings?

So some more data about the speed difference with a more...

Hi All,

I've been working on a DAQ system using the T4.1 and a nice 24bit ADC from TI.

Just recently I've added the USB host MSC library to enable writing my captured and converted data to...

Thanks Paul, will give that a go.

I've been working on a data logger project of late which uses an external 24 bit ADC connected by SPI and writing this to the QSPI connected RAM that can be added to the Teensy 4.1.

This was going...

26656

Very odd to see that the outgoing ping message has "(no response found!) " within it.....

Hi All,

I've finally begun my Teensy 4.1 experience with ethernet. I have assembled the PJRC hardware and connected up to by trusty laptop and loaded the example from Paul via the Arduino IDE (had...