Recent content by alexandros

If I switch to four layers, does this mean that all modules that connect to this bus board must also have four layers with an unbroken ground?

Can you give an example of where these series resistors should be placed? Also, how much resistance for each?

Thanks for the detailed answer and ideas! The SN74HC157 seems like a great solution. Also, I didn't think of routing the clock signal the same way as I did with the data signal, which makes total sense as you point out. The MOSI+MISO1+MISO2+CLK scenario is what I need here. I guess I can use the...

Here's a PDF to the schematic of the bus board. This schematic doesn't include the Teensy, as this is located in another board that connects to this bus board. Anyway, it is a rather complex system, and I don't know if sharing all of it would help. I've attached this schematic. Chips U3 and U6...

I'm using the 74HC595 shift register, and the clock and latch pins are shared among all chips, and not daisy chained. What you said about sync might be the culprit. I'm trying out different versions with a modified shiftOut() function, where I can have control over each signal, where I'm...

I'm trying to build a modular system where modules that contain shift registers can connect to a bus board. To avoid hard-coding the number and positions of these modules on the bus board (there are sixteen sockets where modules can connect, through IDC connectors), I'm trying to detect them...

Oh, that's true. I guess it should have been obvious. Sorry for the noise and thanks for having a look! I can't remember why this line was there...

I'm trying to use eight 74HC595 shift registers over what is probably considered a long distance (approximately 70cm) on a PCB, with quite thin tracks. I've copied the shiftOut() function from the Arduino source, and added some delays, but only the first Shift register seems to be outputting...

That's good information to know, thanks. Is this documented somewhere? It does work and the Teensy goes back to the factory BLINK code, but I still can't upload new code to it. My computer now just doesn't find the Teensy anymore. The only port it finds is /dev/ACM0 and that is not the Teensy...

I have a setup where I power up a Teensy 4.1 externally. I have cut off the trace on the back side of the Teensy board so I can use its USB to program it. I programmed it a few times, but then at some point it was getting stuck and since then I can't program it, Teensyduino just gets stuck, even...

@Mav well, these 10K resistors to ground are copied from Adafruit's schematic from their LM4040 breakout. Maybe they're there because the breakout provides both 4.096 and 2.048 references, and it's not known in advance if both will be used? Kind of a pull-down resistor? No idea really. Anyway, I...

Sorry for not providing a fuller schematic. Here it is. The 2.048V ref is wired to the ADS1115 chips, so its differential mode is usable. The thing is I don't know how many ADS1115 chips I want to have. It should be between 1 and 15, for a total of 30 pots.

I'm trying to use multiple ADS1115 chips to read potentiometers at differential mode, to get the full 16-bit range. To achieve this I'm using the LM4040 voltage reference, passing a 4.096V to the pots (and ground to the other end), and 2.048V to the ADS1115 chips. I'm having a hard time...

I have used Mark's circuit and it works much better, at least with green and yellow LEDs (I had no idea that different LED colors behave differently). I went on and developed the circuit so that a smooth and a non-smooth control of the LEDs is possible, by using transistors and switching between...

Your circuit seems to be working fine, at least better than mine. I tried it out with whatever I had around, which was two 220 Ohm resistors and a 4700uF cap and it worked very well! I tried a second LED with the same resistors and a 1000uF cap, but that did not fade almost at all, and was...