liudr
Senior Member

Write a test code to test your electronics. We don't know how the 12V may have damaged everything else. The very least, find a way for 12V to not be accidentally wired to a Teensy pin. This could involve optimizing your...

Maybe use mcp4725? The chip has i2c interface and is not hard to use even without a library. Here is a link: https://www.adafruit.com/product/935

It depends on which country or continent you live in/on. Here is an enclosure company based in USA: https://www.polycase.com/ Lots of options even handheld boxes if you have drill and router to open holes for...

If the tab completely covers the pad, you have to either use a heat gun or maybe have your iron on the tab for some extended amount of time to try to melt the solder under the tab. I might add a bit of solder paste to...

I just took a look at my LC. The microUSB has two surface tabs that can be soldered by hand. First you want to check the solder pads (2 for the tabs and 5 for the connection) on the board to make sure they are all...

I'm not a drummer so what I suggest may be just wrong: Say you have 5 drums. Build each like you did with the single drum. Then under the middle drum, install a hub. So two left drums wire to under the center drum,...

I guess there's the spec, then there's popular hosts such as windows/nix/macos, then there's device manufacturers. Here's what I have on a square ipad stand hosting a receipt printer: 10ms between setAddress and...

Thanks. Yeah, a better way to add another case with some USB timer will be great but I didn't know how. Hope you find out what else may cause the issue and make a patch. I've heavily modified the library so I will have...

@Paul, Is it related to this issue? This causes issues to https://github.com/PaulStoffregen/USBHost_t36/issues/87 Can you please share what delay command you used? Thanks.

My suspicion is that the code running on keybow causes some delay/blocking during boot so if you add some delay in teensy before it enumerates keybow, then keybow has completed initialization (could be the...

Thanks @mark. I think JLCPCB must have very large rolls and may have pressed the non-framed stencils before shipping. Theirs are much flatter than osh stencil's.

I tried to remove some simple thruhole components with a soldering iron some decades ago and had very poor success. Kind of questioned whether I could learn soldering. It turned out the board was covered with conformal...

In case you are interested,: Tacky flux: https://www.amazon.com/Chip-Quik-SGF991-10CC-Stained-Soldering/dp/B099XCWXX6/

It is, difficult, to look at. While this turned out to be salvageable, you should do some more practice on scrap boards (broken electronics etc) before doing this again! To remove a connector, use hot air rework station...

Thanks Paul! I'll avoid using DMA to access PSRAM. What I want to do is to write some content into OUTbuf, then have the content sent to a USB device using a USBHost_t36 library driver I wrote, and "at the same time"...

This may help you stay with MEGA2560 for a bit longer if you wish to pay the $33+SH price: https://www.rugged-circuits.com/new-products/quadram Do read the tech details if you want to get it: ...

OK, you have the right expectation. It's not impossible but very unlikely unless you have a lot of time, the right tools, and don't mind doing a lot of hard work. I don't know what setup you have and how you can't just...

It's a very extensive project you're developing and managing @paul and despite of my short time using teensy so far I, see an excellent project, platform, and community, so I'm just going to remind myself to grab...

Great! You definitely went above and beyond of merely asking for an answer. You took the information and went ahead with your own investigation, and you posted back your solution. Thanks! This was also a first clean win...

@paul I really wish you would allow a maximal of 1920*1080 image size as most people have this resolution or higher on their monitors and could provide screen shots at this resolution, not the 2000-era 1280 pixels wide....

You need to provide a link to this adapter you got. Nobody knows exactly what you have. I have this one: https://www.amazon.com/Monoprice-Extender-CAT5E-Connection-150ft/dp/B003L14ZTC/ This is only good for USB...

I'm not familiar with the library you're using but I can provide some timing data/diagram of a 2-channel rotary encoder. It's not as symmetric as most theory diagrams picture them. Here is what I have: ...

Maybe you didn't have the right Zener diode. Or it could have been broken. Lower voltage Zener diodes can get damaged by static electricity if they are in non-antistatic bags. If you bought a 3.6V Zener, then it should...

So I am seriously considering running host mode on OTG1 (instead of on OTG2) and device mode on OTG2 so I can have all 8 EPs to work with. This stems from drivers of devices I want to simulate. Some drivers are smart...

So when successful, it took 0.1ms to go from set address to get dev desc. I'm suspecting that it WAS circuitpython running startup routines in the background that caused the device to respond too slowly. If you're...

Totally works! I also made wMaxPacketSize0 dynamic depending on what I want to do.

I wish I had your optimism or skill level. I've been designing boards for over a decade but on 2-layer boards so far. As I mentioned, I only know some things in theory. Hope you can get some prototype boards working....

Thanks @Paul. I think you answered my questions. I may be interested in a few 1062 and the smaller chips with bootloader. It's for one of the projects I've been bugging you guys with weird USB questions for. Should I PM...

Could you post your successful enumeration with the 5-second delay? I am curious whether it is the rp2040 that is too slow to respond with USB requests when it starts up circuitpython and usb device. If you wait 5...

I'm not sure what took the same device so much longer to respond to Teensy than PC. The error was not the setup packet of "set address" that got stalled. The one after it got stalled. It's a request for device...

I found this schematic diagram from an AVR microcontroller. It may be easier to understand since the diodes are drawn almost in line. You can imagine the resistor on the right to external input and Teensy pin on left. ...

Sorry the photo is a bit out of focus as it's too close. You need one Zener diode of the appropriate voltage (3.3V or maybe 3.6V), and a resistor to limit current from your source. This resistor's value depends on the...

I'm potentially interested in making one T4.1 program another. Is there any documentation of the Halfkay protocol? From what I see, my pc is just dumping data to teensy using update HID reports. It'll be nice to know...

Thanks! I had the same question on ep size as well, not EP0, but EP3. I'll try this solution.

I was hoping @Paul would chime in at some point :D Thanks! So if I used the micromod, then both IC_MKL02Z and the correct power sequence are on the micromod, right? I was looking at the schematic. Sparkfun has 3.3V...

The device USB port that you will need to program your board runs at USB 2.0 (480MHz) so that is the part that needs some careful routing. I was able to route them on 2-layer boards that embed Teensy 4.x boards on them...

FYI, the sparkfun micromod Teensy processor is an EAGLE design with 4 layers and has all the essential components to make a basic Teensy 4.x. I think that design will be my personal step 1 towards a 4-layer board where...

What about a less daunting task of using the sparkfun Teensy micromod module? All you need is to customize the carrier board that has EAGLE design file 2-layer and everything. If you've done similarly complex designs in...

"High" baud rate and "low" voltage of 3.3V is not a great combination. If you raise the voltage of your signal using a max3232 to nominal +-12V on the Teensy end, then lower it down to proper level with another MAX3232,...

Every time I open up a BOM, I'm like "Damn! More things are OOS and unreliable suppliers are holding large or remaining stocks so many things and selling at huge profits like 1,000%!" Here is me placing 3 footprints...

1. will the powered hub handle hot-plugging and not cause issues for the Teensy? I won't hot-plug the hub in and out of the Teensy, the concern is about peripherals being hot plugged into the hub. Yes either way. There...

Courtesy of Google search https://www.elecbee.com/en-11308-micro-usb-b-male-30-5-pin-connector-solder-type-for-cable

Alignments: transfer_t: These are device transfer descriptors (dTD in device mode). They are aligned to 32 bytes Transfer_t: These are queue element transfer descriptors (qTD in host mode). They are aligned to 32...

Thanks for the info. I am just guessing, while you are doing SPI transfer, the display can't access its memory (or the portion you're writing to) so it will flicker, against the liquid crystal display's relaxation time...

Maybe since you can't provide details, you can ask your customer for all the details they can provide and compare the differences between your desktop prototype and theirs. Have them ship theirs back to you for...

Thanks PaulS. I checked over and over. I saw no solder jumpers or balls or else. Is it possible that static electricity may have destroyed the output capacitor of the 3V3 regulator and it's shorting? I don't have time...