Thundercat

Hi Jonathan, thank you. The "copilot" part actually is on GitHub, so I'm not sure what to make of that. Thanks for the expertise regarding the code - invaluable! I like the "get 'er done" vibe. I'm still evaluating some other ADCs but that...

Nope, still struggling here. Looking at the source code it specifically says it does use the CMD_MUL_EN bit if you want a multi-register read; in any case, that’s unrelated to using multiple devices. I‘m a bit suspicious about the presence of...

Thank you for the thoughtful reply Jonathan. Regarding the multi device support, buried in the documentation for the ADS1X58 is this: If the other library could work with multiple devices that might work. I’ll try to reach out to them per...

I can’t find that statement - can you point us to it? If you use the alternative constructor you can choose the /CS pin. The author doesn’t seem to have implemented daisy chain support, though. He does still seem to be responsive, despite the...

Well for example, in this library: https://github.com/TUDA-MUST/ADS1X58 Author states multiple devices are not supported yet even though you can define CS pin. In this one: https://github.com/siteswapjuggler/ADS8688a CS pin is baked into the...

I just searched for Arduino libraries for both those ADCs, found some, and they seem to allow selection of the /CS pin in the constructor, so I’m not sure why you think “the libraries do not support multiple units”?

Thank you Mark. Yes I agree 5 minutes of arc is absolutely plenty! I was thinking about a higher resolution ADC though because I figured any ADC I got would actually give me lower resolution in practice due to noise and imperfect PCB, so I was...

ADCs on microcontrollers are always a compromise as they are in a noisy environment and made with a less than ideal process. Go with a external 12 bit ADC I reckon, that's plenty of resolution for a rotary knob (5 minutes of arc!). There's a 16...

Hey all, I'm in process of developing a larger MIDI controller (I've made a bunch in past with Teensys, successfully). This new one is going to have 8 faders, and 8 "endless potentiometers" (they are actually carbon-track pots that Alpha makes...

Beautiful explanation, thank you!

Zipper noise occurs when you change a parameter of sound synthesis path such as oscillator freq, amp, filter cutoff, delay time, etc, in a "stepped" way. Analog signals are smooth, so when you turn say frequency knob in analog circuit the...

Can you share what you mean by "zipper noise"?

I just hope that MIDI 1.0 will continue to be supported. I have lots of hardware using good old midi that just work. Also I have my own projects that I use good old MIDI and 127 different values per potentiometer is more than enough (can't move...

As of January 2026, Microsoft has started rolling out Windows MIDI Services which includes multi-client MIDI ports, lower latency / jitter and MIDI 2.0 support. I don't really care for MIDI 2.0 support to satisfy my needs, but I'm certain my...

Thank you! I added it at the Teensy pin instead of the source - see below. Will this work? Or should it be at the other end? Also, correction from previous post - I got MOSI/MISO lines mixed up.

Don't forget a 100 ohm resistor on SCK. Of all the signals where you would want that resistor, SCK is probably the most important.

Hi again Paul, I've added the resistors - can you just let me know if I put them in the right place and understood you correctly? There's also a MISO line on the main LCD so I included that in the schematic snippet below. Kind thanks! Mike...

Hi Paul, that is SO helpful! Thank you so much! When you mention adding the 100R resistors, I'm assuming you mean in-line (serial) with the data lines? I will take your suggestions on board and test things out. Sometimes I wonder if you ever...

A couple issues have come up with other projects involving several displays connected to SPI. These may or may not be a problem for you. Some displays don't properly turn off their MISO pin output driver when their CS pin is high. You can test...

I’m prototyping. Not sure which way is better. Can’t use both at once as you pointed out. I’m leaning towards just using different CS lines and not using the hardware addressing. I’m not driving LEDs - just some buttons and LCDs. Many thanks...

Totally reasonable. Thank you 🙏

If handling user input is part of the Teensy's "main job" then I wouldn't bother with interrupts, i.e. only if it was spending most of its time on some other task that would prevent it responding in a reasonable way.

Thank you Marsh. I saw that in the data sheet but I'm always a little leery of internal pull-ups. In any case, many thanks. In your experience is simple polling of two devices like this going to slow down the sketch, or are interrupts a good...

The MCP23S17 supports activating internal pull-ups when a pin is configured for input.

Hope a hardware guy can answer this!

Thanks again Joe. For the CS lines, then yes, all outputs, driving the pins high/low. For the first 23S17, they have a bunch of buttons, so they would be input pins. Would it be necessary to add external pull-up resistors to those button lines...

That library supports the hardware address feature, so if you find you do need it, it should be easy to use. BTW, I haven't used interrupts on the 23S17. For your purposes, they don't seem necessary. You are using all pins as outputs. Seems like...

Hi Joe, that's super helpful - thank you! Yes it seems to me like using the hardware addresses just adds more complexity, when I could just use two CS pins instead of one on the Teensy. I'm sure I have an extra pin I can use for this, and it...

I have some experience with 23S17. If you have a separate CS to each 23S17, then you don't need to use the address lines. Those allow you to share a CS between multiple 23S17 and address them from within the SPI data. That's a hardware option in...

Hi all, I've got a MIDI fader/pot box I'm building that will have a bunch of buttons, faders, pots, as well as 9 LCDs. 8 will be small "scribble strips" and one larger LCD to tie it all together. MCU is Teensy 4.1 With such a large project I'm...