Recent content by sicco

Difficult to say without seeing the full code. If you toggle a digital output pin on your 25 us ISR entry and exit, and look at that with a scope, does it then ever miss a cycle? You can also timestamping with ARM_DWT_CYCCNT, that gets you the most accurate timestamping, running at (i think)...

Is it just with Serial6, or also Serial1, Serial2, Serial3, Serial4, Serial5, Serial7 or Serial8? Making a PWM signal in software is maybe not the best way. Hardware timers would be better. The imxrt1062 has plenty of those.

maybe this helps: https://forum.pjrc.com/index.php?threads/t4-adc-real-time-timer-triggered-with-dma-using-adc_etc.76129/

An example for serial with DMA on T4.1: https://forum.pjrc.com/index.php?threads/using-dma-to-store-uart-byte-directly-in-teensy-3-5.71466/#post-315706

Curt, can you share a picture on how your T4.1 is fitted in the target system? One that rules out that other electronics heats up the environment where the Teensy and its PTC sits. Plus are you using SD cards? Some cards use very high currents occasionally - i think when writing to them.

That should be a good hint. So which io pins exactly? And what does a voltmeter show when you measure from those pins to GND in a not yet failed unit? What type and voltage are the zener diodes Z7 and Z11? How exactly do you guarantee that the volts on all Teensy io pins cannot exceed 3.3V...

I had same problems a year ago. It was a card that had high peak currents, and a 5v to T4 power supply that could not give more than ~150 mA to that 5V line. https://forum.pjrc.com/index.php?threads/sd-card-and-max-write-current-when-is-it-safe-to-say-that-it-will-not-bite.75473/#post-346543

On howto “use the ADC to set up a DMA into a buffer at a fixed acquisition rate, say 10kHz to start with, at 12-bit resolution. “ Yes, too demanding for ChatGPT etc… But here’s an example that lets you do 12 bits ADC, 1, 2 or 4 channels, up to 1Ms/s. timer triggered, to DMA...

I also went for separate RTC chips when a battery backed RTC is needed by the application. But I'm just wondering if better software in a Teensy 4 could get us lower VBAT drain in general. Because: if I power up a T4 with only VBAT, i see 43 uA when VBAT is 3V. if I then plug in USB with 5V...

On why T4 and RTC coin cell batteries (CR2032, CR2012 etc) give us months but not >>3 months: is this a software bug / omission after all? Reading the many many register settings in this NXP 2023 Application note, and not getting many hits when searching T4 source codes for usage of e.g...

Maybe you have solder flux leftover or splashes that form a resistor, at delicate points such as nearby the onoff pin, and at points where 5v or even 12v may hit Teensy pins (via flux leftovers) that cannot tolerate that? On the LDO, in that particular project i always have a Schottky diode...

IP66 in the tropics is not keeping the water out. See e.g. https://electronics.stackexchange.com/questions/388866/moisture-trapped-in-ip66-enclosure The issue is that despite of the rubber seals, such boxes breath in and out on a daily basis. During the day in full sunlight the internal...

I can well imagine that the VictorFS systems operate in environments and climates where water may condense where the on/off pin is exposed. Or where insects can creep into the datalogger units and do a short circuit with their body. If water or beasts or mold forms a << 10k bridge to GND, say to...

See this example: https://forum.pjrc.com/index.php?threads/t4-adc-real-time-timer-triggered-with-dma-using-adc_etc.76129/

On why T4 SPI may not work as intended with the MCP3564: with the default Teensy SPI library implementation, in this SPI MODE, the MOSI level for the first bit is either 1 or 0, depending on what the the last bit in the last byte of a previous SPI transaction was. This behavior is specific to...