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I ran the test using GPIO1 as that's what DMA can connect to. The #'s are not too promising, only 21 MHz effective w/o overclocking. Looks like a FIFO will probably be required. I'm unclear as to...

I made some non-DMA timings on the 4.1 at both 450 & 600 MHz

Note that the lib version of memcpy is pretty highly optimized w/ unrolled loops for word aligned data. Also note that the GPIO tests...

I'm actually hoping to tie 2 parallel output A/Ds onto GPIO1. My desired bandwidth is quite high at ~50MHz, which may be unrealistic. I'm willing to use FIFO buffering between the A/Ds and the port...

Thanks Kurt.

I'll take a look. At this point I'm trying to work though as much example code as I can. DMA use on the 4.X is pretty complex and I'm hoping to get more comfortable with the...

Hi @KurtE,

Like @Fiskusmati I am working on connecting an external A/D to the GPIO lines on a 4.1 and accessing it via DMA. It appears that your work on interfacing the OV767X would be really...

I realize that the IMXRT1062 reference manual probably has this info buried in it, but I'm hoping that someone has already worked out what I'd like to know or can point me to where I should start...

Spec page for the sensor says 3.1-5v so you should be okay.

You need 4.7K pullups on both SDA and SCK lines, not a single 10K pullup on SDA. Best to put the pullups to 3.3v.

Run the scanner...

Because you are using Serial.println() to send the data, you are transferring quite a bit more data than you may realize.

All of the data sent is first converted to ASCII so your 16bit values take...

I think you aren't getting the correct status from your color.begin() function which you modified to test and return status as follows:

if ((x != 0x44) && (x != 0x10) && (y != 0x44) && (y !=...

There are several problems with the device and code combination you linked in post #1.

First, the device link is for a 5v 16bit DAC, not an ADC as you say you want to interface. Moreover since...

sizeof (data_obj) returns the size of the object in bytes. If you want the length of say, an int array then try

for(int i = 0; i < sizeof(inputValues) / sizeof(int); i++){

RFID?

https://en.wikipedia.org/wiki/Transponder_timing

Coupled with telemetry you'd get pretty accurate lap timing at both ends as well as exchanging any other useful data.

The default baud rate for the BC127 is 9600.

The sketch in post #7 has:

Serial.begin(9600);
Whereas the sketch in post #11 has:

Serial1.begin(19200);

The responses all seem to timeout,...

I believe the diagram doesn't reflect the suggestion, which is to move the vertical diode between the horizontal diode and the opto.

Kurt,

Note that I am NOT a EE so filter my input accordingly.

There are a number of ways to detect a/c on/off status and your wall wart idea is a reasonably good one.

I would advise that any...

If the display you have is the same as the one on Amazon: https://www.amazon.com/HiLetgo-Serial-128X64-Display-Color/dp/B06XRBTBTB it appears to have 4.7k pullups installed on the SDA & SCK lines so...

My 2 cents on a Wiki.

Although the Arduino Playground Wiki is clearly poorly organized and seems chaotic, that doesn't make it useless nor a wasted effort. Rather, it presents an alternative, if...

So you edited the posted code after I pointed out the endless loop on "while (!Serial) ????

Okay, I guess I can't help here.

What do you think should happen when the following code is executed without USB (and USB Serial) connected?


// Open serial communications and wait for port to open:
Serial.begin(500000);
while...

Hi,

I have several vintage British motorcycles and am somewhat familiar with Smiths tachometers and speedometers. There is often a calibration number printed above the "mph" on the face of the...

Hi,

There are a number of ways to speed up your display output. Keep in mind that the 1306 has no read screen data back capability so virtually all 1306 libraries use an in memory "frame buffer"...

Well that's pretty strange. If the i2c_t3 code doesn't see the 9250 then for sure your library wont.

Looking at the scanner code for Wire & i2c_t3 they both do essentially the same thing, look...

Try running the i2c scanner (examples>wire>scanner) to see if the 9250 responds on addr 0x68. If not, then you have a hookup problem. If it responds on a different addr then you need to change the...

Does this: https://www.segger.com/products/debug-probes/j-link/models/j-link-edu-mini/ work for Teensy 3x? It says it works with all Cortex M cpu's and is only $18 US (non-commercial use, however)....

There's a long running thread on porting Marlin to Teensy/ARM. It gets a bit more relevant here: https://forum.pjrc.com/threads/26015-3D-Printer-Software-with-Teensy-3-1/page4

While POGOs are a popular way to access bottom pins on a Teensy there are breakouts that expose most or all the pins in a DIP fashion, which can then plug into a breadboard or sockets on a custom...

Both your client and server examples hang waiting for the USB Serial port to come ready:
"while (!Serial) ; // Wait for serial port to be available"

If the USB isn't there, the code will never...

Although you are using an AtMega 328 rather than a Teensy, you may be running into the same issue discussed in the first 10 or so posts in this thread. The fix for that issue was incorporated into...

I have had two 3.2's communicating over LoRa without lock-up issues for quite some time now.

However, I have not had any problems since the fix that was incorporated into Teensyduino 1.36 (which...

Pim,

I did not mean to imply that the double clear of the IRQ wasn't needed as your post (#39) clearly showed that the first clear was not reliably working for you.

I do think that the _mode...

The v1.76 RadioHead library linked above in post #43 won't compile due to an error in RHGenericDriver.cpp.

The function at around line 155 should be changed from


int8_t...

Somehow an earlier post of mine got lost.

I think the 3.2 vs 3.5 thing is not really the issue. In your earlier post (#30) you stated that the sample sketch was running without problems using the...

Hmm,

Glad you got it working.

I have no clue as to why HIGH works and RISING does not.

I tested the race condition fix with a Teensy 3.2, and I believe that KurtE was using a 3.2 as well. I...

Hi,

I don't have your hardware setup so I can't run your sketch. However, I did read the code you posted and saw a problem which could explain the "lock ups".

In the "loop()" portion of your...

Paul,

Arduino 1.8.2 w/ teensyduino 1.36.b4, teensy 3.2 w/ RFM95 lora 433. No problems with the teensy-supplied library.

IMO, the rising vs high "fix" is simply narrowing an already small...

While I agree with the idea of avoiding prints in ISR's, in this case the interrupt timing is non-critical. The Rf9x will hold the state of an IRQ until it's read, and then not interrupt again until...

Hi Epyon,

If you're experiencing hangs or other strange behavior in the Radiohead lib it might help to see if there's a disconnect between the current RH state and the interrupt source. I ended...

Sorry, I'm not aware of any such registry.

The RF9x LoRa modules are pretty much sub 1 km range in non elevated, line of sight environments. Moreover, the LoRa spreading algorithms greatly reduce...

The 433/915 ASK radio modules require a preamble to synchronize the receiver. Both the rc-switch and virtualwire libs use approximately 32-36 bit periods for the sync preamble. Also, the bit rates...

Well i took a look at the RF69 module in the Radiohead library.

Mike McCauley provides some pertinent info in the 'h' file:


/// All messages sent and received by this RH_RF69 Driver conform...

I, perhaps incorrectly, assumed that latency in communications between the camera and the remote flash would be a problem. I understand that the 4 flash calibration may be less sensitive to latency...

I assume it all depends on the shutter speed used for flash sync. On a classic SLR film camera I recall that 1/125 sec was the norm.

My Canon underwater setup uses fiber optic for the remote...

LoRa sacrifices data rate for range. Semtech has a calculator where you can enter various factors such as bandwith, spreading factor, & payload size and determine the total air time for your packet....

Not quite sure what your goal is other than system state monitoring. For simple current monitoring of a pump to determine it's state (none = off, low = cavitating, normal = running, high = locked...

The RH lib has software SPI which can be specified in the constructor for the particular radio driver. In addition Bill Greiman has a software SPI driver he includes in his SdFat library. I believe...

Which fix? The ATOMIC ops or the move of the _mode var sets?

Also can I get your changes to test with? I'm very interested in transaction support for the RH lib.

I thought about turning off interrupts around the setModes, but was worried that the SPI stuff might take long enough to disrupt other time critical interrupt handling. So I simply moved the _mode...

Moving the _mode sets is pretty safe. The IRQ flags on a RF95 are broken out so you know the source of the interrupt (RxTimeout, RxDone, RXCRC, TxDone, CadDone, etc). Unfortunately, the RF95...

Hi Kurt,

Is your version the same as what is in the Teensyduino 1.35 distribution? If so, the posted sketch does hang reliably (on a 3.2 w/ the Adafuit rf9x Feather module) on the second...

Environment: Win7, Arduino 1.8.1, Teensyduino 1.35, Radiohead v1.62 or v1.67 or Teensy RH version

I’ve been trying to get the example sketch on Adafruit’s RFM9x page:...