avsteele

Thanks Paul, JMarsh. I think I identified the issue. I believe occasionally the interrupt execution is being delayed by about (max) 68 clocks cycles more than usual. Basically the delay spikes to this value, then decays away as certain external...

I don't have any specific advice about the floating point issues you're seeing. But I will mention that certain biquad filters are notorious for needing high precision in their coefficients. As a general rule of thumb, the smaller your pass...

I think what I am seeing is a real effect having to do with the phase of the signal and not necessarily any floating point errors.. It would still be useful to know 1) how to set the priority of an interrupt on a pins 24,25 (GPIO6 12 and 13)...

It should not be needed, volatile FPU registers will be saved if any ISR accesses them.

I'm been building a digital LockIn Amplifier. I am seeing very regular instability in the output of calls to e.g. arm_biquad_cascade_df2T_f32 This occurs approximately every 1 million calls, or ADC samples collected. The magnitude of the...

Since you will be powering the Teensy off VIN, there is no need to route the USB power to it since you aren't dealing with an intermediate chip like a CP2102. In my setup, I just route the D-/D+ and it works fine.

USB functionality is built into the chip NXP processor chip. If you want to keep the USB conversion on the baseboard, you can pick up the D-/D+ USB lines on pads under the bottom of the Teensy as shown here. Pogo pins can be used on the...

Great thanks for the suggestions Ken. I hadn't thought of the pogo pins. One question about the Vbus connection. Is it truly not needed to route these to the Teensy board at all? I don't know much about the specifics, but I know with the...

I am planning to integrate the Teensy4.1 onto a larger PCB. (a Eurocard-like 'motherboard') I would like to be able to communicate and program it via the virtual com port as usual but do not want to use the built-in micro-USB. What are my...