AJL Electronics

Not that I'd have time either way but generally if someone tells me "I don't know the details of how to build something but I've picked the parts that should be used" then I run a mile.

When using a tap, it is important to keep backing it out to clear the swarf as it cuts and a smear of grease will keep the swarf together. There should be no risk of destroying the insert unless you go at it like a Gorilla!

Yes, no. I give advice based on my own personal engineering experience over five decades. It is up to you what you do with it. All examples of these that I have used take an M3 nicely. If you have one which is larger than normal, then tap M3.5...

I have used many of them, an M3 tap is DESIGNED for metal.

A carbon microphone is a variable resistor, so hopefully that will help you to utilise it. Originally it would have a 50V power supply.

Easy enough to put an M3 tap through them.

The Sumotoy library is rather outdated at this point. @KurtE and myself revamped the Sumotoy library for the Teensy and you should try that. The library is included with Teensyduino. It should be compatible with the Sumotoy library but has...

Finally got the display to work. 100r resistors on MOSI, SCLK and CS cleaned up the ringing nicely.

I am now going to design it for the Teensy 4.1. I do have a few issues to solve on the 3.6 version first, the pressing one being that the keyboard (Ps/2) input seems to die after a sentence of more than a few characters. The Teensy continues to...

Indeed. I have tried that and Controlio, even on a paid for service they are unable to help much and often send you off down rabbit holes. When you point it out, apologies are forthcoming and sense resumes for a few minutes. Then it goes back...

I know this is an old post, but nobody seems to have put it right before. The two batteries will stabilise at a similar terminal voltage and no harm will result. Paralleling batteries is an established method of improving current capacity.

A 7805 from 12V is probably going to be close to exceeding its ratings, especially "bareback". Even at 200mA, a fraction of its capability the dissipation is 7V x 0.2A = 1.4W. You would be better with a switching type regulator.

you can also cut the red wire on the USB cable instead of cutting the trace. this way you can use the USB as a data only cable without power. It is not a good idea to source power from 2 places as the voltage will backfeed, example, power bricks...

This was an irritation here too, as I was using the secondary SPI on the 3.6 to avoid the Audio board. Now of course the Audio board uses it and the SPI goes back to convention. It is going to need yet another PCB redesign to use it in this...

That's very helpful and I will experiment further. Is the touch panel the GS1680 type? I have had zero luck in getting mine to work, but persevering with it when other jobs are sorted. Fonts wise, I could do with one a third smaller than...

The holes are large clearance holes for plastic mounting pillars and I understand that boards are drilled before processing. Therefore there should be no issue, although after finding a major error on that board due to mirroring (again!) I will...

That is the working set with the T3.6. The device is behind the display with very short lines direct to the pins on the display.

Many thanks for that suggestion, how low can I go? I did put the 'scope on the SCLK signal and was surprised that it wasn't a nice clean square wave of a constant frequency. But hopefully that just shows that I am unfamiliar with the way SPI...

Tried that: //tft.begin(12000000); tft.begin(12000000, RA8875_800x480); // Init the tft

Referring to this thread... https://forum.pjrc.com/index.php?threads/ra8875-and-4-1-with-spi.69787/ Was anything ever achieved? I have two of these displays and they work fine with a Teensy 3.6. However I have been unable to get a coherent...

I uninstalled everything and reloaded it step by step and the 4.1 has appeared and seems to be working.

In Devices, I have checked that it appearsas a USB keyboard. Removing that device and reinserting Teensy reloads it, so I am confident that the hardware is OK. My suspicion is that the loading of Teensyduino boards manager is failing. I do see...

I have been using a T3.6 without issues. Connecting the same computer and cable to the Teensy 4.1, it is not recognised and is missing from the list of boards. It doesn't appear in the list that can be loaded either. The Teensyduino add on has...

Every board with high pin-count BGA parts is at least 4 layer, though usually 6 or 8 or more - its the only way to route all those pins from the middle out!

It is.

1.6mm I would guess unless it is a multilayer PCB.

A hardware debounce might be useful perhaps?

I reckon its on line 42 - its the answer to life, the universe and everything. Apparently...