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You make a good observation. The ATOMIC_BLOCK code (that I'm seeing for the first time so take this with a grain of salt and subject to further study) seems like a good solution, though it's a strict...

If you are certain that your application is AC, any of the DACs will likely work of you. If you expect to do very low frequencies or DC, then the PT8211 becomes a good choice. The PT8211 is a...

It looks like a "#" character is missing.

The way to enable these things is with a preprocessor macro, so use "#define" preprocessor operator.



#define AUDIO_PT8211_OVERSAMPLING

#define...

I've been running experiments with PJRC PT8211 audio board (stereo I2S 16-bit DAC) replacing the output capacitors with shorting wires. It works beautifully. Good results from DC up to 500...

We have been checking PT8211 behavior fairly closely over the last week. Connected using the PJRC standard board-on-board style... No real surprises on the noise front.

Off topic... Has anyone...

Bottom line question: Does anyone know of issues in driving DC-to-kHz signals with a Teensy audio shield?

I've been involved in a multi-channel (64-channel) analog data acquisition project and...

I don't think I've ever seen a PWM-controlled device that places tight requirements on the accuracy of its clock rate. The two parameters that almost all PWM-driven devices use are carrier frequency...

Interesting coincidence... Reading some tech docs on the Raspberry Pi over the weekend, I discovered that's approximately how they handle PIO drive strength:...

I have implemented DMA-based UART communication using Kinetis microcontrollers in the same family as the one in the Teensy3.5. The only reason we could justify the major investment of development...

I agree with chipaudette, our project has had noise issues and channel cross-talk issues using the 4 onboard ADCs in a K60 design. We are "getting along OK" but have discovered a need to take great...

Board flex is a known problem with BGA parts, maybe SparkFun could consider a thicker board design? I am unfamiliar with the physical specs on the MicroMod form factor.

My work project had several...

First answer: The program as written has asked the the executive to run two threads with equal priority. Both threads ("tasks") are written to run continuously, so the apparent gap in execution of...

If your target application has safety implications (a question you and your co-workers would need to answer), then the you can change the Big Decision into a few smaller ones:

Are you willing to...

My coworkers and I have been using Kinetis (K60, K61, approximately Teensy 3.6-generation) parts for a fairly large data acquisition system. During early design, we were optimistic that the...

I'm not surprised by their variability. In our project, the original plan for them was to build a desk-sized strain gauge system while our project hardware being built, since the real sytem is very...

One of my favorite shops is SparkFun Electronics at https://www.sparkfun.com/ who offer many products including a variety of load and force measurement components. They offer load sensors (single...

Hi Trensicourt, I grabbed the PDF you linked. The "0.5 to 4.5V output" version and the I2C version are shown in block diagrams as supporting 2.7 to 3.3V power supply and signalling. That does not...

Correct, the LC processor can use the pin according to the processor's settings. It is a 3.3V pin, and as seen in the schematic could be used as an I/O pin without difficulty. The LC uses a 74LV1T125...

Count me one of those who suggest a motor driver. Adafruit sells breakout boards for development (or production in case you decide to keep it in final design). The TB6612 and DRV8833 chips...

Neat idea especially when the target PC does not enable its remote desktop support capability which is the most common way to control a Windows PC manually.

It looks like you've got the basic idea...

One API that I have wished to implement is to change from "disableInterrupts / enableInterrupts" to "curLevel = setPriority(newLeveli)"; one option for "newPri" should be "such a high priority that...

Though your ISR is likely already cached given that it is probably being executed frequently in your tests, there are are some additional tools that may help with speed.

About two thirds of the...

I'm beginning to understand... you are not simulating ust a 27c256/27c512, you are simulating an 27c256/27c512 connected to a multiplexed address/data bus. That is a different animal...

Are you...

Given my continued interest in whether a Teensy can emulate an EPROM...

Is your code changing the direction controls on the pins that serve as ADDRESS lines? For any addressed hardware component,...

Sounds like you're on your way. I've wondered for several years whether a Teensy could emulate an EPROM, considering the number of times my co-workers and I wished for rapid turnaround during...

You may want to consider how long OE# is expected to be active. If you are fairly confident that it is held active for limited time, then it may be OK to enter the ISR on OE# falling edge, then...

In case you have not found the code already... "avr" is basically a holdover from early days, but all teensy products are supported there. Two files you are likely to be interested in studying. I...

The discussion so far appeared to be related to 27c256 or 27c512 parts, which are just classical EPROMs, with nonmultiplexed address/data signals. So the discussion so far still fits the description....

I wondered whether that was the case...

edit:

If you can count on your target pulsing OE# low for each access the logic is way simpler. If your target holds OE# low for a limited time...

The RT106x processors are so fast that a well-written very tight interrupt service function triggered by the leading edge of OE# may be more likely to work properly than a DMA solution, and be a bit...

Is this a "spare no expense" project, or a "get the best results without going overboard" project?

The ADCs in the Teensy 3.2 microcontroller can pull enough current during sampling that they...

FWIW, I have been involved in a project that drives Kinetis K60 and K66 microcontroller UARTs at their max rate (150MHz sysclock /16=9.375) across optical links through 50MHz-rated transceivers. In...

You make a good point (and was exactly what I though during the time we struggled with the byte-slip issue), so I went back to examine the settings we use. We do set RXWATER to 1.



It's also...

That reminds me of the strangest CPU/DMA race condition...

My project involves really fast comms with UART0 and UART1 in the Kinetis K64 / K60 / K66, (our locally designed hardware, but the K66 is...

The analog to digital converter in the Kinetis K66 microcontroller has an analog comparator feature that can be set up in a variety of ways to generate a conversion complete interrupt only when it...

Sounds positive all around. Supports my hypothesis and early test results, that communicating basic configuration and diagnostic constants will work predictably. We are already ensuring proper...

Thanks for the response. Given that nobody has reported obvious problems with binary FP interoperability, I'll just go with it and verify the results carefully. The project already uses FP arithmetic...

Hi everyone, with the increasingly common of floating-point hardware in recent NXP Kinetis parts including the T3.5, 3.6, 4X, I wonder whether anyone here has begun using binary data transfer of...

The Segger unit would probably work, though it involves their software and more importantly to me, their licensing policies. When we were looking into debugger support hardware and software, one...

Three years ago, I bought an Olimex FTDI-based JTAG programmer, a JTAG-SWD converter and a cable to match ARM's 10-pin footprint, with a total cost less than $100 (it could have been $50, I don't...

...This leads to an interesting question from someone who knows nothing of audio (comms & measurement guy here). When one refers to "reverb", is the standard of practice to separate the channels with...

Hi Rowan,

It turns out that my project at work is just finishing a design using an MK66 part, so I am interested in starting to use an MK66... I was a Kickstarter backer for the Teensy 3.6, and...

On a project that does not use the Teensyduino code, I have been successful in using the watchdog interrupt to great effect, using the ISR to store some state before the reset happens.

I had code...

Perhaps a way to support through-hole resistors while consuming limited board space: Place the holes 0.10 inch apart, allowing the resistors to be placed vertically. There will inevitably be...

Question about the product page... It looks like there are two copies of the top side illustration, none of the bottom.

Congratulations on the new release! Two units ordered, looking forward to...

Not really relevant to the question of using a watchdog to awaken a CPU from sleep, but for those who read these comments, I have an update on how the Kinetis watchdog hardware works.


I use a...

On the topic of interrupt service and CPU performance... The K64 in the Teensy3.5 is an amazing performer. I've been using FRDM K64F devboards (with 10/100 Ethernet and a little IP stack) to support...

Rcarr's observation about the idle state of leads to a question about UART handling at a register level: I have not looked at the Teensyduino driver layer recently, but there's a possibility that...

Thanks to all, my co-workers and I appreciate the info.

Hi Willie_from_Texas, what system clock rate are you using to obtain those numbers? At first glance they seem impressive.