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I have a DAQ system with Webservices (serving pages, streaming over sockets etc) but currently only with HTTP and WS ie unencrypted. Before I go to HTTPS and maybe WSS I wanted to gain a feeling of how much computational load it will add going this next step. Does anyong have any data for this...

My input hardware interface uses high speed optoisolators with totem pole outputs so no pullups/downs required.

Will be used for high speed encoder counting so need to use this library. I have some pins spare so will parallel them up and define these as regular digital inputs I can read independantly.

Looking more into pinMode etc and discovered that setting the pinMode to input for these encoder inputs stops it working. Next question: Is one able to read a pin status (as an input) that is defined as a pin for the encoder library? (ie and not set as input with pinMode)

I have a DAQ product which I am adding quadrature encoder capture to. The hardware uses a Teensy 4.1 and the simple example in the library is showing the library and hardware to work using inputs 33 and 37. When this is integrated into the main project I do not get any counts at all and hence...

@nieuwemaker have you sorted out the issues you were having? I suspect at least some of it was likely due to trying to read and write huge or uncontrolled chunks/files in one go. I have also recently discovered that I had a problem with running out of ram when conditions like webpages closing...

After a bit more tweaking, the performance has been improved quite a lot: Threshold of available space before write dropped to 1460, delay(2); after write changed to yield(); while (f.available()) { // Check Connection if (!client->connected()) { success = false; break; }...

Example debug dump for a jpg Client connected: 192.168.2.100 Client count: zu GET /website/media/posts/2/homepage_2.43.jpg HTTP/1.1 requestline: GET /website/media/posts/2/homepage_2.43.jpg HTTP/1.1 Host: 192.168.2.177 header: Host: 192.168.2.177 Connection: keep-alive header: Connection...

Hi nieuwemaker, I am having very similar issues serving multiple files, no just from SD card but also from flash. I have created the following minimalist webserver using the ServerWithListeners example by Shawn as the starting point. It is working reliably for me, however in the much more...

In the end, I only needed to remove the check for the flash ID, since this will not work with encrypted hex. Working nicely now with ehex files from SD card and web-based GUI and filemanager.

@Dogbone06 did you have any issues with FlasherX aborting due to bad hex lines or invalid hex code? (removed a chunk of verbage here after reading Paul's document relating to ehex files) Did you need to comment out any of the hex integrity checking in the update firmware function? ie in...

Thanks all for your work on this. I intend to implement flasherX into my application to perform remote updates with a locked T4. A question for @joepasquariello : I already have a webserver that allows the upload of files to the SD card over ethernet. Would you recommend implenting flasherX to...

Hey RVH, I have the same issue as you but get around this by using TyCommander to trigger the bootloader and then the Teensyloader does it's thing. Have a look at page 17, section 6 on this user manual I have for a product using the T4.1...

I have a product design that uses a locked T4.1 and no easy access to the prog pushbutton. Therefore I am looking for a method to trigger the bootloader and programming with an ehex via the usb port. Current idea is to use TyCommander to trigger the programming which Teensy loader. It seems...

Looking at the board again, the cut made is quite shallow so I suspect something else has gone wrong with this board.

I use teensy 4.1s in a prodct of mine and need to cut the VUSB to 5V jumper. This has worked fine for a couple of boards so far but the last one I just cut I fear may have damaged something. How deep can one cut into the surface before the likelyhood of damage?

Considered using Platform IO? I'm using it with Teensyduino 1.59 very happily and with VS Code quite a nice editing environment etc.

Capture of writing 255 to port with readback of 255

So I've been discussing this issue with a person from Microchip and decided to look for any other transmissions on the bus that might somehow get the device into an odd state. There was a burst of data being sent to address 0x62 (the MCP23008 is at address 0x20) for a graphics LCD library. Going...

Maybe it's worth hooking up the IRQ to confirm that conversions are being completed?

Capture below shows the result of writing 255 to the port when configured as output, then immediately reading back the port value. Bit 2 does NOT get set but all others are.

Checking that all bits are configured as outputs during initialisation by reading back register 0x00 ie IO direction register. It confirms that this has been set to 0x00 ie all bits as output. This is on I2C bus 2 which is showing the issue with bit 2.

Another data point that makes it a bit weirder I think, turning them all on in a single message ie 0xFF still results in gpio2 not being set, only on I2C2. Reading back the port value I get 251, so bit2 is not set. Will look more into the bit directions register setting, as it really looks...

Hi MarkT, yes that would be the most plausible if it didn't work just fine when I put it back onto I2C1. Issue repeats for multiple boards of that type and another board design. Also with MCP23008 of different production batches/years.

Ok good point. However the problem I have is this is the only difference I can see between the two buses and this is the bus that gio2 on the expansion chip cannot be activated. The traces look identical otherwise I believe.

UhClem, thanks for making me take a closer look, you are definitely correct..... and this may help me find the root cause of the issue. Those blips in the SDA2 line are not actually a start or a stop and maybe I have something else in the system driving that line. Will look into that further...

I have a support request in with Microchip, lets see what they say. Missing from the initial submission, I am using the Adafruit library: https://github.com/adafruit/Adafruit-MCP23008-library Thinking of changing over to this one as it is still being maintained...

Hi All, I have a project with a number of MCP23008 digital io expanders on both the I2C bus 1 and bus 2. This is on a Teensy 4.1, running teensyduino 1.59 and being built in Platform IO. Curiously I am not able to set the GIO2 output on when the devices are on bus2, bus 1 is fine. The only...

The block diagram above shows an ADC chip by TI that has 4x internal ADCs which therefore allows it to sample all channels at the same time, eliminating and phase/time shift between samples. This may be beyond what you are trying to do, I'm not sure. The reason I suggest you inject a different...

Hi Roni, we will need a bit more information to be able to assist you. Directly connecting piezo sensors to the Teensy ADC inputs is not a great idea since Piezo devices can produce quite high voltages without suitable clamping/limiting circuitry in place. So it is possible you have damaged the...

Yes Rezo, good point (I'm using this for a large RAM buffer at the moment) Might need to go to a full custom Teensy4.1 board to get access to the FlexIO for some really high performance ADC.

Sounds like you might need a QSPI or parallel data interface to the ADCs. I have a system sampling 4 channels at 128ksps and 16bit with a 50MHz SPI interface, and this bus would not be able to support 200ksps. If a QSPI port can be made available on the Teensy 4/4.1 this would be very helpful to...

Thanks guys, fully locked it will be.

hi defragster, just to confirm, the key is written to within memory (fuses?) in the main processor prior to locking, so is there any way without going to extreme lengths that the key could be extracted? I understand JTAG is still enabled until the final lock process is undertaken. Is there...

Hi jmarsh, is that because the key is kept in the location that is locked off? If so this is of course a big oversight on my part.... :-(

I have a product I want to sell commercially soon andafter some discussion here previously I will distribute the firmware as an ehex. All seems well and I have the product running an ehex just fine, but I realise that if I do not perform the final locking process it can still run a normal...

confirming I can read *.json files with this library no problem

I'm developing using Teensyduino on Platform IO for a T4.1 and using sdfat file system. I know that it supports long filenames but does it also support more than 3char filename extensions? Reason I would like this to be true is for json, yaml etc files for configuration etc

Hi Gef Those expansion devices over I2C will not be much good at all for analog signals. They are really suitable for low speed digital IO. There are SPI versions of these devices available that can obviously increase the update bandwidth however this still would be poor. It looks like you are...

Hi bigdlin, For a data point, my board has no issue running the SPI clock at 50MHz for the ADC I'm using with a Teensy 4.1.

This seems very curious and not the norm: Typically the SPI bus is shared and additional CS lines are used to select the chip you want to talk to. Why are they doing it this way? bigDlin do you have them wired this way? Is it working? Also I meant to ask previously, have you tried running...

That chip produces 16 bit results ie 16bit multiplexed ADC.

Is the data actually 32bits? or is it a 24bit converter sending a 4byte result? Depending on the converter, some will allow the result (eg ADC) to be sent as 3 bytes (24bits) instead of the 32 saying you 25% throughput.

I had been using PCBWay for everything up until recently when they dramatically increased their pricing on 4 layer boards. A 100mm x 100mm 4 layer board from PCB Way is about 4 to 5 times the price of the same design from JLCPCB which I found incredible. Quality from both has been great so...

Looking at your loop, it seems that you will keep opening and writing to your file indefinitely. Is that why you have append as an option/mode?

Hi DrM My ADC input full range is only +-1.2V hence the +-4V is plenty of room. I am using these as my front end buffer amplifiers. They are working very well in my current application...

Hi DrM Looking good. How much current and at what voltage ripple are you getting out of your design? I have now used a charge pump device to do something similar but with 5V input and +-4V outputs. I have a DAQ board which requires a bipolar supply for some front end op-amps...

One thing to think over is that the Teensy 4.1 is not 5V tolerant so if at some time you have accidentally pulled up to 5V maybe you have damaged the I2C bus IO on the Teensy? Do you have an DSO or logic analyser to look at the signals?

That looks correct. However one issue you need to be very careful of is ensuring that SDA and SCL are not pulled up to or being driven to 5V. Is your ADC running off 3.3 or 5V?

In my working system I used the address 0x48, 0x49 etc