Forum Rule: Always post complete source code & details to reproduce any issue!
Tab Content
  • DerekR's Avatar
    10-19-2019, 04:25 PM
    Hi Dan, Welcome back:D I presume you are aware of the two other break-outs that have been released over the past few weeks? Both use castellated cutouts to contact all of the under-board pads. A few of us have...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    10-16-2019, 07:25 PM
    Yesterday I received two packages in the mail, (a) more T4s to destroy, and (b) samples of FRDM4236's board. So I got to work and assembled two of my slightly modified (stretched) versions of Blackketter's board, and...
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-13-2019, 02:56 AM
    @dkryder, Don't think I gave up without trying :rolleyes: I sent a couple of hours trying to prise them apart... It was just not possible to heat the pins through both boards and extract the pins. In the end I even...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-12-2019, 02:52 AM
    My bad, in fact my very, very bad today:( :( :( So, I was all very pleased with myself this morning when I wired up breakout #2. Everything went swimmingly, I soldered all the castellations, installed the pin...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-11-2019, 12:13 AM
    Well, I had a very pleasant and unexpected surprise today! I had ordered my modified versions of Blackketter's breakout board in 0.8mm thickness from OSHpark before we learned of the woes with those boards. They...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-10-2019, 02:51 AM
    That would be fantastic, thank you very much. Yes, I'm in the USA (Mass). I'll PM you with the details. I've been getting quite frustrated lately because I've tested most of my code on the T4 in bits and pieces...
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-09-2019, 07:21 PM
    Looks very good, and I'd certainly like to try it! I note you are using 0.8mm board thickness. Several of us have tried OSHpark with @blackketter's design with 0.8mm and found that routing of the castellated edges...
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-09-2019, 01:51 AM
    Next questions: 1: What do think of Dan's (@loglow) SMD 2x5 header to connect to the lower board vs the castellated cut-out? Personally, having built many T3.6 breakouts from loglow, I like them. ...
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-08-2019, 12:49 PM
    Sounds to me like a "ground-loop" caused by common currents in the power line connection. These can be real nasty to track down because they can be dependent on your wiring. I've had that problem from time to time,...
    10 replies | 156 view(s)
  • DerekR's Avatar
    10-08-2019, 02:02 AM
    Hi guys - How did the pogo pins on Paul's beta breakouts work out - were they reliable? While playing around in KiCad this afternoon I started wondering if that might be the way to go???
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-07-2019, 05:33 PM
    Michael, I'm very frustrated. I want/need to get going with using the T4 in real tasks, but unless I can get at all those pins, I'm stuck. I started to build a prototyping board this morning using the loglow beta...
    46 replies | 2083 view(s)
  • DerekR's Avatar
    10-07-2019, 12:45 AM
    I would think that this is a hardware problem, not a software problem, unless your sawtooth has a very, very low frequency. I don't follow what the sawtooth is actually doing in loop() is it just a loop counter? ...
    2 replies | 85 view(s)
  • DerekR's Avatar
    10-07-2019, 12:12 AM
    Re thicker boards - you can purchase male headers with longer pins that will make the soldering easier on the top. I have a few with long pins on both sides. And it's relatively easy to move the pins up and down in...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-06-2019, 11:51 PM
    Andy - You beat me!!! I didn't get very far at all today, I could find my plastic bag of female headers :( We have a local electronics parts store that's closed on Sundays, so I'll be able to get some in the...
    10 replies | 189 view(s)
  • DerekR's Avatar
    10-06-2019, 02:47 PM
    From defragster: J and that is where I'm totally confused! The T3.6 had a bunch of alternate pins for the SPI bus and it was necessary to use those alternates to have the TFT and audio board connected at the same...
    10 replies | 189 view(s)
  • DerekR's Avatar
    10-06-2019, 03:20 AM
    I've run the T4 with the ILI9341 Display, and the T4 with the Audio Board, but not all three together. That's my job for tomorrow. To be honest I'm still a bit confused as to whether they will play nice on the same...
    10 replies | 189 view(s)
  • DerekR's Avatar
    10-06-2019, 12:40 AM
    Now there's a coincidence! Just today I uploaded to the forum (for another member) a couple of my AudioGrabber Audio Library objects that let you extract blocks of data from the internal audio data stream to your...
    5 replies | 140 view(s)
  • DerekR's Avatar
    10-05-2019, 09:15 PM
    DerekR replied to a thread fft overlap add in Audio Projects
    I found this old test sketch that I wrote a couple of years ago. I think it might do exactly what you are asking about. As it is it doesn't do anything useful: 1: It takes an Audio block, and concatenates it with the...
    6 replies | 113 view(s)
  • DerekR's Avatar
    10-05-2019, 04:03 PM
    @LoShu -As you requested I have attached a zip file containing two "grabbers": 1 AudioGrabberComplex256 2 AudioGrabberReal256 in separate folders, each with a simple example of their use. I have several other...
    63 replies | 11003 view(s)
  • DerekR's Avatar
    10-04-2019, 08:32 PM
    Sure. Do you want the complex or real? Give me an hour or so... I'll upload them both on the forum under this thread. Aside: I was getting the grabbers ready to upload as a library to GitHub three days ago when...
    63 replies | 11003 view(s)
  • DerekR's Avatar
    10-04-2019, 07:02 PM
    @defragster: Fantastic - works like a charm. It was driving me crazy! I find it hard to believe that I'm the only one who had this problem. Thanks a bundle, Derek
    3 replies | 102 view(s)
  • DerekR's Avatar
    10-04-2019, 04:44 PM
    For the past three days I've been trying to track down a bug that "bricks" the T4 on program upload! I now believe it's a genuine problem in the Teensy code. I was preparing some Audio Library compatible objects...
    3 replies | 102 view(s)
  • DerekR's Avatar
    10-04-2019, 02:51 PM
    I've been thinking the same as @blacketter. I've been playing with concurrent tasks on the two cores of the ESP32 with FreeRTOS, and I'm impressed. I believe it might be a good time to think of a move to RTOS when a...
    65 replies | 2160 view(s)
  • DerekR's Avatar
    10-04-2019, 01:48 AM
    I read through a press release on the 1170 today. All I can say is WOW! When I read of the dual-cores: 1GHz M7 + M4, I am already wanting to sign up! @Paul - are you taking pre-orders? I'm drooling, I'll take two :D...
    65 replies | 2160 view(s)
  • DerekR's Avatar
    10-03-2019, 10:09 PM
    I was just playing with rectangular pads. I think they would be more resistant to tearing from the board. However, this IS blackketter's project. I think we should respect that, and work with him...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-03-2019, 09:16 PM
    Seeing as I already have the board in KiCad I'll take a shot at playing with the layout, drill size, pad sizes, etc
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-03-2019, 08:42 PM
    Yep - just like mine. I'll look into oshPark's policies on returns/manufacturing errors. But I don't know about the hole plating on such small holes, it may be just not feasible... @Blackiketter - Were your...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-03-2019, 08:13 PM
    Well, that's a total fail and a huge disappointment! Mine just arrived, and all three are headed for the trashcan. 1) The lower cut-out is completely missing, ie it's solid! 2) The plating on the the top cut-out...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-03-2019, 02:58 AM
    Mine shipped yesterday (10/1)... will try them out as soon as I get them. BTW - Yesterday I uploaded to OSHpark my modified version with space between the side header rails, as in post #36. I actually made and...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    10-01-2019, 03:52 PM
    @KrisKasprzak Wow, that's very interesting about the ILI9341 libs! I think I'll splurge and get one. I did ask about HX8357 somewhere on the forum but got no response. (I've also been thinking about getting a...
    14 replies | 243 view(s)
  • DerekR's Avatar
    10-01-2019, 03:45 PM
    Adafruit has a 3.5" 480x320 HX8357 display for $39.95 (expensive) here. The also have a library for the HX8357 which can be down loaded. There is also a "Feather Wing" version which is currently listed as...
    14 replies | 243 view(s)
  • DerekR's Avatar
    09-30-2019, 08:33 PM
    DerekR replied to a thread Teensy SDR help in Audio Projects
    You might also take a look at AudioSDR here. It is a single Audio Library object that contains a complete SDR software package, but it is designed expressly for f32 processing and therefore needs a T3.6 or T4. My...
    2 replies | 113 view(s)
  • DerekR's Avatar
    09-30-2019, 02:34 PM
    It seems that this thread has split into a couple of somewhat disparate conversations: 1) Getting the audio library 4096 FFT to work, which I think has been established? 2) Analyzing/displaying partial frequency...
    63 replies | 11003 view(s)
  • DerekR's Avatar
    09-29-2019, 02:03 AM
    I am about to publish a set of Audio Library compatible objects for the T3.6 that were created for live performance. Unfortunately I had to stop working on the project last year for health reasons, but the system has...
    29 replies | 1323 view(s)
  • DerekR's Avatar
    09-28-2019, 02:42 PM
    A couple of suggestions: 1) In the original post it was mentioned that it was only the lower part of the spectrum that is of interest. You might try a "zoom FFT" approach (google it), and examine only what you want....
    63 replies | 11003 view(s)
  • DerekR's Avatar
    09-27-2019, 04:04 PM
    A couple of minor things to think about: 1) PJRC has announced a new revision of the Audio Board for T4 that will be released any day now. In the meantime you can still use the current boards, but they don't plug...
    22 replies | 602 view(s)
  • DerekR's Avatar
    09-26-2019, 12:39 AM
    @loglow - Hi Dan. I haven't been very active on the thread because the breakout has continued to work well (except for pins 35&36). I have it running 24/7 on all sorts of software and peripheral chips and boards...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-26-2019, 12:20 AM
    DerekR replied to a thread Audio over Serial in Audio Projects
    The Teensy Audio Board/Audio Library supports SPDIF IO, and multi-channel TDM (time-division-multiplex) through the CS42448 chip...
    4 replies | 110 view(s)
  • DerekR's Avatar
    09-25-2019, 01:00 PM
    @defragster - Wow! What a massive effort by @tonton81 et al (including yourself)! It looks exciting BUT from skimming the thread it also looks like the devil is in the details for implementation on each member of the...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    09-25-2019, 01:25 AM
    How strange! I had just started to bread-board a T4 and a ESP32 with a built-in ILI9341 display, and was sitting here pondering the best way to have them transfer data to and fro -in particular from the T4 to the...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    09-22-2019, 06:45 PM
    @blackketter - I've made a minor change to make the breakout compatible with my prototyping boards (VELLEMAN Eurocard 3-Hole Island PC Board (ECS3)) by adding a 0.1" gap between the the two rows of pins. Otherwise I...
    111 replies | 3183 view(s)
  • DerekR's Avatar
    09-21-2019, 05:56 PM
    I agree in principle with @luni but look at the y scale: the graph axis is given at intervals of 5000 steps! What I don't understand is that the glitch seems to drop down and then recover almost immediately. I've...
    9 replies | 200 view(s)
  • DerekR's Avatar
    09-21-2019, 05:45 PM
    This has been done for quite a while now for use with loglow's breakout boards for Teensy 3.X on Tindie. Use flux, tin the pads first, and use solder braid to clean the pads just leaving a thin coating of solder. Add...
    5 replies | 145 view(s)
  • DerekR's Avatar
    09-21-2019, 02:45 AM
    Debouncing is real easy. Basically you just put a capacitor across the switch. When the switch opens the capacitor charges through the pull-up resistor, and the voltage rises "slowly". I'm not sure what your...
    9 replies | 200 view(s)
  • DerekR's Avatar
    09-21-2019, 02:24 AM
    What sort on encoder are you using - optical? mechanical? Is it the quadrature type? If it is mechanical - you may need to debounce the switches electrically (R-C network). That could be the source of your...
    9 replies | 200 view(s)
  • DerekR's Avatar
    09-21-2019, 12:09 AM
    @MichaelMeissner: I was basing the need for resolving conflicts between the display and the Audio Board on Paul's description when describing the SPI library here: I presume when he says "Audio DAC" he means the...
    4 replies | 109 view(s)
  • DerekR's Avatar
    09-20-2019, 04:21 PM
    On the PJRC page for the 2.8" TFT display (here), Paul gives the T3.x SPI connections for the display, with and without the Audio Board. This page has not been updated for use with the T4. I'm just getting around to...
    4 replies | 109 view(s)
  • DerekR's Avatar
    09-15-2019, 07:01 PM
    @firehopper, @dkryder - Thank you so much - that worked. I didn't even remove the Teensy from the breakout, just held down program button as suggested, and it came back to life :D I didn't know about that trick -...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-15-2019, 05:31 PM
    I seem to have bricked my T4 by simply pressing the mini-tactile power on/off switch!!! I simply tried it as part of the debugging of the breakout, and the T4 turned off after the five seconds but won't turn on again!...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-14-2019, 11:50 AM
    Where can I find KurtE's pintest? I looked on GitHub.
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-14-2019, 02:41 AM
    I have never known excess flux on boards to create device function problems. For short-term prototyping projects I often don't bother to clean it up at all. But it sure makes the boards look spiffy. :cool: I'm...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-12-2019, 05:08 PM
    Follow-on from above: If you want to take an arbitrary waveform, say an existing sinusoid, and alter its phase by 90 or 270 deg, I can let you have a "good" Hilbert transformer audio block. It takes a single (mono)...
    7 replies | 246 view(s)
  • DerekR's Avatar
    09-12-2019, 04:56 PM
    I always use rubbing alcohol with a good scrubbing with a toothbrush (preferably not your current one) and then mop up carefully with a paper towel to absorb the residue.
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-12-2019, 04:45 PM
    @loglow I measured it again and guess what - it is now 2.93 volts. Sorry about that - I'm embarrassed. I have two more T4's arriving from PJRC tomorrow. They both will ultimately end up on break-out...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-12-2019, 01:42 PM
    Try the following direct IQ generator Audio block, I think it does what you want. I've used it in my SDR work for a couple of years. Bonus: It works on the Teensy 4.0 with the Audio card :D ...
    7 replies | 246 view(s)
  • DerekR's Avatar
    09-12-2019, 03:05 AM
    Thanks for the nice comments, Tom. I played with the Soft-Rock kits a few years ago, and as I recall they had a SI570 chip on board, and I'm trying to recall how it was tuned??? Maybe it was through the USB, but it...
    16 replies | 579 view(s)
  • DerekR's Avatar
    09-11-2019, 08:37 PM
    @mjs513 - I had the same problem but noticed it early enough to move the connector away - and that's when the spacing between the SD socket and the connector became impossibly tight. On the same issue, re my bad...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-11-2019, 06:18 PM
    What is the function of the mini tactile switch? I thought it was a reset/reboot?? It certainly pulls its signal low when pressed - but I can't see that it does anything. I tried void setup() { ...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-11-2019, 05:54 PM
    Well, it blinketh most brightfully. BUT a couple of fails as well. 1) There is no way you can put a battery in the holder once everything is assembled and the long side headers are installed. so I unsoldered one tab...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-11-2019, 12:39 PM
    @KurtE The chip is in a very small black plastic carrier that looks very similar to the black 0.1" jumper. I at first confused it for a jumper...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-11-2019, 12:36 PM
    Assembly is complete, but I haven't yet powered it up. The following are my comments on the kit, and how to assemble it: 1) This is definitely NOT a kit for the inexperienced. I have many years of electronic...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-11-2019, 12:12 AM
    @firehopper Wow! You sure have good vision - thanks! Even when I magnify the image I can just make out might be the blurriest of the letters SII. But yes, the bar is in the right place, so I'll go with it. I...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-10-2019, 10:05 PM
    Re #95. So here's what I've gleaned so far, I believe that the ambiguous marking is "SII" which was recently bought-out by ABLIC. I've looked through their product line, but I haven't find a chip that might be a...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-10-2019, 02:28 PM
    How do I tell the orientation of the TPD3S014 chip (ie pin 1)? I have examined the package under a jeweler's loupe and I can not see any evidence of a dot or a notch on the package anywhere. I can read SII (or IIS)...
    263 replies | 14675 view(s)
  • DerekR's Avatar
    09-04-2019, 03:22 AM
    Just to keep the thread on topic, here a couple of photos of the construction of the AudioSDR BareBonesWSPR T4 construction: and bottom view the right hand board holds the QRP Labs receiver module and their 40m...
    16 replies | 579 view(s)
  • DerekR's Avatar
    09-03-2019, 08:39 PM
    Hi guys, You ask some great questions! I'd love to keep discussing these, but I just don't know what the best forum would be. Is the Teensy forum the appropriate place - because these are broader DSP/SDR issues? ...
    16 replies | 579 view(s)
  • DerekR's Avatar
    09-01-2019, 02:21 PM
    Thanks Jim, I spent a lot of time working looping at frequency domain processing and FFT convolution for use in SDR, but ended up asking myself: why am I doing this? It's interesting - I spent 40+ years teaching...
    16 replies | 579 view(s)
  • DerekR's Avatar
    09-01-2019, 02:30 AM
    I have just finished wiring a new board to allow the T4 + Audio Board to work with the QRP Labs Receiver Module. I nearly fell off my chair when I compiled the BareBones WSPR receiver (that's included in the AudioSDR...
    16 replies | 579 view(s)
  • DerekR's Avatar
    08-30-2019, 11:08 AM
    I uploaded some small mods to GitHub and called it Ver, 1.01. There are no functional differences: 1: Removed the #include "Streaming.h" from AudioSDR.h (which was a hangover from debugging). 2: Added #include...
    16 replies | 579 view(s)
  • DerekR's Avatar
    08-29-2019, 08:43 PM
    Hi Frank, Super to hear from you. I'll be really, really interested to hear what you think. Please let me know of any problems, criticisms etc (I'll PM my email to you). Nobody else has tried audioSDR before I...
    16 replies | 579 view(s)
  • DerekR's Avatar
    08-29-2019, 01:28 PM
    @bicycleguy That's great - I look forward to the outcome!!! That's funny about the order of the .h files. I've run it as is for a couple of years, but I have always had all component files in the same directory...
    16 replies | 301 view(s)
  • DerekR's Avatar
    08-29-2019, 04:30 AM
    @bicycleguy, Whoops! How stupid of me! You don't need AudioLagComp.h for this demo. That's part of the error compensation package. Here's what you do need: ...
    16 replies | 301 view(s)
  • DerekR's Avatar
    08-28-2019, 07:05 PM
    Thanks for all the answers, guys. @WMXZ We're talking about two inputs on the line-in of the Audio Board. The whole data stream of one channel is slipped by one sample with respect to the other, there are no...
    16 replies | 301 view(s)
  • DerekR's Avatar
    08-27-2019, 08:24 PM
    @MikeDB - thanks. Yep, I just confirmed that the trouble still exists on the T4, see here. Are you saying that a mere mortal might have a shot at fixing the problem, or is it so buried in low-level stuff as to be...
    71 replies | 5201 view(s)
  • DerekR's Avatar
    08-27-2019, 08:00 PM
    For a couple of years now I've posted about the "bug" where the two I2S channels randomly are out of synch with one another by a single sample. This apparently is a problem on many MCU's, so it's not a specific Teensy...
    16 replies | 301 view(s)
  • DerekR's Avatar
    08-25-2019, 09:09 PM
    Not arguing with you, and I know it's not just a Teensy problem, but I can't think of a single reason why this should be true, after all we have clocks all around the I2S interface, and 44.1 ksamples/sec is hardly a...
    71 replies | 5201 view(s)
  • DerekR's Avatar
    08-25-2019, 06:48 PM
    @DD4WH - Have you had a chance yet to look whether the T4 has cured the "twin peaks" bug that has driven me (and possibly you) crazy over the past couple of years with quadrature I2S inputs on the T3.6? I'm just wiring...
    71 replies | 5201 view(s)
  • DerekR's Avatar
    08-25-2019, 05:17 PM
    I'm pleased to announce that I have finally uploaded my AudioSDR project to Github here. I've had it working for many months now, but wanted to give it a good workout before releasing it. AudioSDR is a single-block,...
    16 replies | 579 view(s)
No More Results
About DerekR

Basic Information

Statistics


Total Posts
Total Posts
220
Posts Per Day
0.18
Last Post
Teensy 4.0 Breakout Kit 10-19-2019 04:25 PM
General Information
Last Activity
Today 12:05 AM
Join Date
05-24-2016