Search results

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    Exploring voice shifting and amplification for the hard of hearing My personal hearing aid is based on a T3.2 and does 'some' frequency shifting. Have been using it for many years. My Neighbor, having tried several $$$$ solutions and also having lost most stuff over 4kHz, bought an...
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    Soil Moisture Sensor based on Heat Capacity

    The USDA and the World Meteorological Association has published several papers and decisions on soil moisture instrumentation. Texas A&M, UC Davis, and UC Riverside agricultural engineering people have all have done a lot of work in the measurement of soil properties. Search for 'apparent...
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    Teensy 4.1 vs 3.6 -- Thermal Performance Data

    What is the purpose of testing the board at 80C ambient? HALT, HASS, or ESS ? Extended environmental verification? Your product's V&V ? If so, dunno if data has any meaning other than the board itself; that is, environmental tests are done for system-level verification and validation. For...
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    8-bit Teensy deprecated soon ?

    Is this a course for an electrical or computer engineering syllabus? Is it part of a computer science syllabus? As a senior engineer that is oft dragged (kicking and screaming) into interviews, my colleagues and myself have some concerns about the stuff being taught to university students where...
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    TI ADS1256 8 CH, 24 bit A/D

    Probably best to take this query to espressif's forum at
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    Teensy 3.0 temperature rating

    Tested a T3.5 to -20C last year. Decreased ENOB and the writes to an EXTERNAL SD (on-board SD not used in this application) had a very small error rate that was not present at 24C. If the freq went out of spec, I did not detect it. The ultimate source for ratings and limits are the specs...
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    Small li-po batteries

    Older 'soft' package LIPo batteries have less immunity to mechanical damage and can be prone to separated electrodes when compared to liquid electrolyte Li ion batteries. You probably already know this, but the three major stressors for Li batteries are complete charge cycle count, thermal...
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    questions for Paul

    Greetings Sir, Some questions per your post on hackaday (pasted below). Was surprised that support for Linux was such a major effort. I also believed that if you limited to publishing stuff for most common such as deb and rpm, that Linux support was minimal. What can the community do to improve...
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    Serial Data Transfer Library Finished!

    Yep, looks like a simple checksum - no CCITT polynomial to be found. And it seems to be segmenting data inefficiently. Checksums are ok, but less reliable than CRC.
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    Surface Mount Female Headers for Use with Teensy 3.5 w/ Pins on a PCB

    Oh geez, really? But you still have to find a part that is within the supply chain of your China fab. Bazillions and bazillions of this stuff. SMT headers tend to lower mechanical limits for failure when compared to equivalent through-hole stuff. And have had better reliability using non-RoHS...
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    Off topic - Quantum computing

    "can a modern processor emulate this concept ?" No. Although there is stuff such as the Rigetti Forest, it does not emulate, but is a demonstrator. "is anything happening in the world of development boards to make this technology available ?" There are no off-the-self industrial solutions...
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    Designing a pcb ?

    You cannot purchase Eagle. A basic subscription costs approximately $100 USD per year. Plus whatever portion of your soul you are selling to the 'cloud'. Have not used Eagle for several years because its autorouter updates broke my DRC, and because ver 5 made KiCad usable and reliable, and...
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    Submillisecond latency RF link

    Did something similar using a high-freq version of NFC (manchester NRZ). Totem-poled transistors (push-pull config) used to directly drive the tank circuit to the antenna. So you will have to roll your own on this, or use an off-the shelf radio.
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    GND vs AGND

    Have never been a big fan of these current sensors, but they are functional for simple stuff. The 'best' design practice would probably be to leave the fault pin open and connect the 'ground' stuff to the Teensy analog return.
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    Teensy 3.5 temperature range

    Concur with XFer and brtaylor. Based on several HALT series done with Teensy 3.2s, do not recommend use in industrial control products where internal ambient is under -20C. As 'industrial' grade stuff is typically not limited to battery power, can use stock Teensy boards by parking a Dale...
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    Isolate teensy from switching power supply

    Am not certain that a supply (bypass) cap will do much to arrest voltage or current output surges, and is intended to provide short-term pulsed-current demands. That is, the bypass cap is intended to provide a delimited current surge. A series L might help for some current surges. And a properly...
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    Clipping an input signal

    May I suggest ?
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    Attach a Teensy onto a PCB vs raw chips - production?

    Yet another 'it depends'. Have two model series for my side business. For simple low-end stuff (atmel 328s, TI 430s, etc), have never used any of the canned proto boards. But this is to mostly to control component quality, EMI, and environmental ratings. For the hi-end stuff have used T3.1s...
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    High humidity environment

    Simple (electrical) varnish coating will be ok for higher %RH environment where absolutely nothing comes out of solution; that is, non-condensing. Otherwise the only two solutions (pun unintentional) that have worked for mine and my employers' stuff is either an IPx4 or better rated enclosure...
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    ADC performance, achieving 16 bits (or very close to it)

    Am not certain if the A5250 reference makes your point. It states the 'obvious'. Gain and offset errors are the (relatively) easy stuff. INL, DNL, reference stability, Z-mismatch, digital noise and most other stuff are not so easy in either hardware or software. Agree that some portions of the...
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    Choose the right Open Source License

    Caveat -> NOT a lawyer. The meaning of OS/OH has been litigated and legislated differently throughout the world. The EU courts treats OS licenses differently than the U.S. and Canada. Unless your work is a derivative of another OS project having specific requirements per the license, then what...
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    FCC Certification

    1. starts at 9kHz. - exemptions for unintentional radiators are found in 47 CFR 15.103. - certification not necessarily required unless connected to mains. - did a subpart B test series for a box using a T3.1/3.2: Class A ok, but Class B did not have much margin. 2. if the test samples are...
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    wanted: 3.5's already pinned

    Apologize for the OT diversion. Have been supporting LabView stuff at various sites for over 25 years; and did one or more (will never admit in public) production ATE systems for the factory floor using LV. But never by choice. Simple greed and avarice bent me to the client's wishes. And other...
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    Teensy 4.0 (hypothetical) pin assignments

    We pause this conversation for a comment from the resident crank. USB 3 energy and current levels are problematic. And the new IEC62368-3 is designed to rein in some the the weird stuff now found in USB 3 cables and connectors. To put it succinctly, USB3 can be a fire hazard. Have seen some...
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    Teensy 4 RTOS

    YASQ (yet another stupid question) What are you good people doing that would require more than a scheduler/state machine?
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    Compliance issue

    I do not speak for PJRC, my employer, or the Klingon Empire. There is no such official animal as a RoHS or REACH 'compliance certificate'. No requirement unless the equipment is within scope of a marking directive. Typically, most electrical stuff will require a 'CE' mark to indicate...
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    MIDI nearly silent stepper motor interface - motor loudness test

    What are "acoustic counter waves" ? Noise cancellation?
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    Temperature and Humidity (again)

    Will assume for various technical and legal reasons, PJRC has not included specific tabulation of environmental specifications. And, as this is a 'systems' question, will have to be a DIY thing. This is what my evil little mind did some years ago, when men were men and doggies did not wear...
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    Adapting Teensy for Industrial Automation(Arduino Compatible Shield,Intrinsic Safety)

    Typically, NRTLs will not, and cannot, provide design services, other than to review a design proposal or do a gap analysis on an existing design. If your knowledge of a standard exceeds that of an NRTL assessment engineer, then talk to someone else or another NRTL. For UL, an excellent source...
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    Teensy 4.0 (hypothetical) pin assignments

    Agree. Probably not gonna find much robust and capable analog stuff buried in a powerful digital glob. So if we need this level of GPIO and processing power, one would probably goto external stuff such as your nice audio boards, or some of the increasingly cheap 18 to 24 bit ADCs and DACs...
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    Adapting Teensy for Industrial Automation(Arduino Compatible Shield,Intrinsic Safety)

    This is not the forum for IS design. Your team needs to invest in an initial study of the software and hardware and environmental standards that are scoped for your category and class. One of your team should be designated to do the the compliance stuff (safety/EMC/environmental/life cycle...
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    Microsoft is aquiring github!

    Today's conversation with the NRTL client test data program auditor. NRTL guy - do you have any code on github? me - nope, all on a local svn box NRTL guy - show me me - looky here [tappity tappity] NRTL guy - ok, do not really understand, but looks like good control Geez, kids and and their...
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    Microsoft is aquiring github!

    Dunno, could be considered the same stuff as using 365... says the crazy old geezer that uses subversion. Do not be surprised if 'they' decide to force a mickeysoft login, as has happened in the land of goggliania for everything. In any case, was the only way github was gonna survive. Long...
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    Suggest next Teensy with Cortex M7

    We are about exceed the processing power of a rpi or pi-zero without the madness of a huge OS, and we need to stay calm in our anticipation? An entirely unreasonable request.
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    New playback videos all MCU with FTDI screens

    Dunno, perhaps I am too stupid to understand what is being said. Am certain that most of our august group would like to help this guy, but simply cannot parse the question or issues. Have had similar language difficulties with employer's Asian customers. The engineering community should...
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    New playback videos all MCU with FTDI screens

    Dunno. Is spam crassly commercial, or just a babble post with no useful information or no relevant question ? It is, in my opinion, the latter.
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    BME280 Teensy Library

    Contamination, per se, was not the problem. We had a batch of 29 sensors with deteriorating tolerances after a few months of several cycles per day (20 to 80%RH, -20 to 40C), of working 24/7. We bought another batch of sensors and life is much better: the IngSoc Emperor is happy, and the proles...
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    GND vs AGND

    Hath spake "Your end-use application should never allow these two returns to touch.." Now read that again. Did not say to "never" connect gnd and agnd. Said to not connect in the END-USE application. Human units, you must parse the comments of the other human units literally and carefully. Oft...
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    GND vs AGND

    Discussed in numerous threads on the PJRC forum, and in the microcontroller reference tome. In a nutshell, 'GND' is for digital returns (I2C, I2S, SPI, GPIO, etc), and 'AGND' is the zero equipotential for your analog stuff. You never want digital signal return currents flowing through an...
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    Teensy Goes to Space! Have subsequently did a partial regression on a unit with a Teensy 3.5, where decreased margins were indicated. Again, sample of one, so poor statistical relevance.
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    lo noise stuff

    Have done things much more stupid than this, so verified the ardy IDE config for 24MHz on the tech's windoze box and is correct. Mine typically uses SCons on Linux, so very little mouse clicking or thinking is required on my part, so is difficult for me to screw this stuff up (famous last...
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    lo noise stuff

    Am doing some lo-noise stuff (per CISPR22/32 class B limits). For various reasons, not all related to noise, cannot exceed a 24MHz clock. Have tested various ATtiny and other AVRs, and some M0 and M4 STMs, and some TI 430s, and Teensy models 3.2, 3.5, and LC. So far, the two most 'quiet'...
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    how fast is the analogRead on 3.5 and 3.6?
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    state machines

    Vague hand-waving follows. State machines should not be a problem for 'moderately' sized code. Have done some state machines with T3.1s and T3.2s, but do not directly use the arduino system. That is, not certain how you would know where stuff is, so ability to discern a memory issue not known...
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    Teensy 3.2 not receiving RX data

    "I also noticed the teensy board was very hot with only 5 volts to Vin" Nope, do not want to touch these units. And does anyone want my four T3.2s that had 1200Vdc on the USB port? Only happened once...
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    High PWM frequency with 16 bit accuracy for switch-mode power supply

    SMPS and linear source are contradictory terms where "no ripple" is your reference specification. There are some things that you can do to approach a low noise design, but you will not "reduce the requirements of the analog components"; you will probably increase the component count and size of...
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    BME280 Teensy Library

    Condensation not likely, as same problem with sensors in all of my employer's environmental chambers at both factory and engineering sites. And my code running the chambers reads a parametric look table to avoid approaching the dew point. So now running several sensor models 'in parallel' and...
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    How to kill a Teensy

    MOVs can be dangerous. They will oft explode while 'arresting' the surge and start a fire. Study annex Q of IEC/UL60950-1, IEEE C2-2012, and UL1449. Product safety does not care about reliability. When large current and voltage surges enter equipment, the primary design objective is to prevent...
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    Teensy CC Dummy Load +300W

    The ADC probably not really 18b unless the op amp and the reference choices are re-considered. To get at least 16b of useful data, my stuff typically uses a 24b ADC and low-noise/lo-Vos/low-Ib op amps; not to mention decent resistor specs. Same with the Vref - you need low noise and low tempco...
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    Control IOs from your Mac or Windows computer (Wirekite)

    Interesting. Did a much less complete version of Firmata-like stuff last year after the factory techs insisted on blowing up $$$ per month of test equipment. Built about 10 of these where the USB port was floated and isolated from the computer. Blowing a $50 Teensy board no problem where the...