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For the couple dozen who have cloned it, you might want the update today. I tested more with one and two channels.

https://github.com/rjsdotorg/ADC This version is up to 14 channels (uses DMA and faster if only 2) and streams and/or logs data to uSD. 2 channels streams up to 1.3MHz to a laptop or uSD. Tested with Teensy 4.0, still developing BTW this has the uSD holder soldered to the board whereas the 4.1...

Ha! Someone actually read it! Gone now. Lazy way to break out.

https://github.com/rjsdotorg/ADC This version is up to 14 channels, and streams and/or logs data to uSD. 2 channels streams up to 1.3MHz to a laptop or SD. Tested with Teensy 4.0, still developing

The Python in the capture was simply first in the list of the PS command output, with "Arduino IDE" down the list. The gist was simply the use of Get-CimInstance to debug when in Windows. BTW VS Code running PlatformIO does use Python in its toolchain. I just tried to replicate the whole...

VS Code / PlatformIO said "COMM" Python process was just an Get-CimInstance output example - I had been running Arduino IDE for a while then switched to VS Code which failed due to zombie processes holding the port. Sorry, it was unclear. I had learned to use Get-CimInstance to track down the...

I think I have another to try. I don't have a scope but do have a nice AS-1250 ADC to check the pin V separately. The STD is small. A 3V battery would be a good test too. Part of the idea here is to turn any Teensy into a 1.3 MHz triggered O-scope, and I'll put a Zener and resistor on A0 to test...

Now with both channels at 1.3MHz! https://github.com/rjsdotorg/ADC

As one might expect, the STD rises with rate (12 bit counts):

BTW, the .cpp is attached, and serial cap code is below (can't attach...). Output is 1339.4 ksamp/sec streaming uint32 over USB 2 """ serial_capture.py – Capture Teensy ADC DMA USB streamer data into a numpy array. The Teensy firmware streams raw binary uint16_t samples in 512-byte...

I looped the 3.3 V pin to A0, the board is powered by USB/laptop. I have a new streaming .cpp code which streams one channel of data at 150k back to the laptop running Python serial capture. It appears to vary from ~3.22 to 3.26V - does that seem typical?

I was using Arduino IDE and then switched to VS Code. I "closed" Arduino/Teensduino but several Arduino processes were still left running. I did a PS script: Get-CimInstance Win32_Process | Where-Object { $_.ProcessId -in 7708,4544,9920,13008 } | Select-Object ProcessId,Name,CommandLine |...

I ran the test 7 times and saw quite a variation in max busy: rbMaxUsed 1280 12032 1280 768 6656 768 min write us 4.68 4.68 4.68 4.68 4.68 4.68 max write us 5.54 5.53 5.54 5.54 5.54 5.69 min busy us 18 17 18 18 18 18 max busy us 1390 11674 1380 822 6412 823

slash2 with your test and Type is exFAT Card size: 63.86 GB (GB = 1E9 bytes) Manufacturer ID: 0X3 OEM ID: SD Product: SP64G Version: 8.0 Serial number: 0X28D120F8 Manufacturing date: 1/2012 I get about 2x your max busy us :

joepasquariello I don't quite see why 256 here? #define BUFLEN (256) // bytes per write

My own bench.ino tests with Sandisk XC is ~23MB/sec over SDIO, 2x faster than HC: FreeStack: 449400 Type is exFAT Card size: 63.86 GB (GB = 1E9 bytes) Manufacturer ID: 0X3 OEM ID: SD Product: SP64G Version: 8.0 Serial number: 0X28D120F8 Manufacturing date: 1/2012 FILE_SIZE_MB = 5 BUF_SIZE = 512...

I was being approximate 10.7 ENOB is from https://www.pjrc.com/teensy/IMXRT1060CEC_rev4.pdf OS typically adds 0.5 bits of resolution for every doubling of the sampling rate, I usually rely on oversampling and exponential averaging / filter - I'm not sure what the IMXRT1060 does exactly with its...

Are you still using analogRead()? You should really consider the DMA ADC examples in the Teensy set. Mine attached does 1.17Mhz (one channel) with no averaging so ~10 real bits and with 8x averaging you should get almost 12 real bits and still ~130ksmp/s

As an update, I'm thinking that the behavior is mostly in the controller of the BLDC (can't update first post now). "specs" say "PWM signal speed regulation around 10-20kHz" but actually runs from hundreds up to 100kHz. "signal feedback requires pull-up resistor." which sounds like open-drain...

A Teensy-based time lapse camera would be, well, based...

I have a small BLDC motor (5 wire with internal control board) and doing PWM control. As per the Teensy docs: Anytime you are doing PWM at high duty cycle it glitches every 4.3-5s, with exactly 500Hz. This is with or without a 4.7k pull-up. Ie, analogWrite(2, 255); enables it - actually >=240...

FWIW I have a 4.0 overclocked to 916Mhz with a 1cm^2 heatsink and only see 50C running a modified SD bench. 916 might not be needed, I'll see when I finish ADC processing code.

I searched for @beermat and SDIO etc but found no posts. Google either...

Ah yes. But why are the benchmarks nowhere near 120MB/s?

I just bought/tested a "new" uSD Sandisk 32GB Ultra UHS-1 to compare with older models. Using SDIO and inserted in solder-on connector to Teensy 4.0. In left-right order, SdFat/bench.ino example results: Use a freshly formatted SD for best performance. Type any character to start...

Yes, a lot of the first post is now 404

Look at the Bill Greiman example TeensyDmaAdcLogger.ino I also have some test code that writes ADC samples to uSD at 1.1MHz Using the Teensyduino library with Visual Studio Code does allow the helpful use of GitHub Copilot

If accel is planned, please use ISM330DHCX. I think it has the best specs for small SMD at the moment. I use it with Pi Zero 2W Is CSI (Camera Serial Interface) ribbon connector in the realm of possibility?

Ah I think I see And Bill Greiman did not use file.is_busy() in his example TeensyDmaAdcLogger.ino if (n >= 512) { // could be if ((n > 512) && !file.isBusy()) { if (rb.writeOut(512) != 512) { Serial.println("writeOut() failed"); file.close(); return; } }...

With the main.cpp code RMS noise is ~15 counts at 12 bits and no averaging, 1.17Msamp/s. Here is one second of photodiode data no data jumps/missing even at high slew rates:

Good non-ISR examples using `writeOut()`, but currently working on the ISR version from RingBuf.h and TeensyDmaAdcLogger.ino * This ring buffer may be used in ISRs. Use beginISR(), endISR(), write() * and print() in the ISR and use writeOut() in non-interrupt code * to write data to a file. I...

In addendum to another post, here is my modified version of RingBuf ISR example (based on TeensyDmaAdcLogger.ino) It always does 512 byte writes, but I can't follow in the lib to see if it does: - always test for SD.is_busy() - write only if SD is NOT BUSY

This uses Bill Greiman's RingBuf.h, and I can't follow it very well, yet, and don't see an *.is_busy(). However VS Code Copilot seems to have found and fixed the main issue "adjusted buffer allocation and pointer math so BUF_BLOCK_SIZE is treated as bytes (fixes cache invalidation/offset...

I am testing a modified TeensyDmaAdcLogger.ino example (attached) with a ping-pong buffer of 2 by 512 // Preallocate .5GiB file, multiplying 8 by 2^26, resulting in a value of 536,870,912 bytes, or 512 megabytes (MB) const uint64_t PRE_ALLOCATE_SIZE = 8ULL << 26; // Ping-pong DMA buffer. DMAMEM...

In my case, I'm happy to say that switching from the Adafruit SDIO SD board to the soldered-on simple holder on the Teensy 4.0 made all the difference.

In my case, I'm happy to say that switching from the Adafruit SDIO SD board to the soldered-on simple holder on the Teensy 4.0 made all the difference. Same 10 year old Sandisk 16GB HC card, no blips at 256 byte intervals. Photodiode card on pin14/ADC0, 586ksmp/s: However, I do see what appear...

Google AI mode just told me this which I'm testing: To use the ADC library (by Pedvide) with manual DMA control, you utilize the library to configure the ADC hardware while using DMAChannel.h to manually set the TCD registers. Manual ADC-to-Memory Configuration This setup captures 128 samples...

pseudo-code still might help others I am (currently) just writing to uSD at 553ksmp/s, and, also getting the every-512 byte glitch. You can see it is also railing the ADC occasionally:

What is your current code, if I may ask?

I also just read that pinMode(<pin>, INPUT_DISABLE); should be added for analog inputs. I have not tested yet, but will. I am assuming it is the case for ADC0... ? Also here

I wish they were for sale (?) I would have done that instead. We have also ground down board edges to create castellations, but if pre-populated we used stripped 30ga as jumpers - Bill was worried about static during grinding: (That was MSP430 based deep sea camera)

I had to think on that too What Pio does with his (very nice) board is swap using 2 layers:

As someone pointed out, the part is 1.1mm pitch, while the pads are 1.0mm

:D

The Molex 1051620001 arrived and I soldered one on. FYI this really calls for solder paste and a microscope. I bent 1,2 & 7,8 inwards a tad, soldered and had to use wick to remove excess on a couple. The mechanical issue is that the card rubs on the 2 SMDs and needs tape under it so as not to...

As someone suggested, I tried a 47uF cap at the power input to the SD hat, which made a barely discernible difference. I have not added anything to the Teensy 4.0

Shouldn't be too bad (I hope). I did not see the exact which is part on the 4.1... (?) I also bought more SDIO breakouts

I ordered the Molex 1051620001, so I'll test next week.

BTW this is my Python viewer code I keep on the uSD card: import struct import matplotlib.pyplot as plt format_string = 'H' dl = struct.calcsize(format_string) l = [] with open('IsrLoggerTest.bin', 'rb') as file: while True: raw_data = file.read(dl) if raw_data!=b''...

I saw that Greiman's post does not seem to suffer ticks with the 4.1 I am using my 4.0 boards and Adafruit SDIO board with ADC0. With them I see a VREF-related (?) glitch every 256 samples, which is the 512 byte write points. It is erratic for 28 samples at 815ksamp/s, droops then rises ~42mV...