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Hi, Im working on a project which involves sending serial commands from a raspi 4 to a teensy 4.1 pins 0 and 1 (serial1 i think). Current using unshilded 3 core ribbon cable twisted and its about 25cm if that. One of our concerns is not dropping serial bytes. We are planning on running a...

Lol. I had actually been trying to get a routine that was specifically not doing any Interupt stuff and just waiting so I could be sure that odd results weren't due to wierd Interupt stuff I had no hope of tracking down. As it happens, for this particular part of the program there's probably not...

Well, had mixed success with your suggestions. I've been having a nightmare with serial dropping. Everything seemed to work well until a Windows update and now it'll work great for a bit, then I have to start resetting the teensy and reprogramming, then sometimes restarting serial monitor. Then...

brilliant, thanks, ill let you know how i get on.

actually, looking more closely at your results, have you any idea why the first 2 seem to be just largely junk but the third seems consistently spot on?

hmm, thats interesting. I couldnt get anywhere close to that. That would be more than good enough. Ill revisit freqMeasure and give that ago. Does this example basically stay with the measurement loop until its done and then continue? I think when i tried freqMeasure, my code (not the code...

Hi, Im currently working on an analog polysynth and one of the most crucial things is tuning of vcos. They will need quickly tweaing as the thing gets used and teperature changes. As good as some of these vco chips are, theyre not digital! I have managed to use freqMeasure to successfully tune...

Ok, I did see that (p#4), but the pennys only just dropped. I think i see what you mean now. ok. Ill look into that. Thanks

That sounds like ground loop or cheap psu somewhere on your pc, Have you a battery powered laptop you can try with? Chances are you wont get that 60hz mains loop in your car unless you maybe have a mains inverter in there.

Thats answered a lot of questions about the device for me and. i can largely stop digging now. I take it that your last comment about version numbers is so that you can reuse the calibration values or whatever else is stored more easily as my firmware update could then rewrite the data to...

Thats inspired! I like that a lot. Thanks.

Thanks all, Well, I did a little more digging. Turns out EEMEM for AVR does do what i would like but is part of avr/eeprom.h I cant seem to find an equivalent. The blank eeprom does appear to be written 0xFF. I've decided for now that if address 0 > 0 then i'll run calibration. As im loading...

Hi, I have a calibration routine I want to run the first time the teensy 4.1 is turned on. I figure i want to set a boot flag in eeprom, probably at address 0. Check whether this is set to (lets call it is_calibration_set for ease) is_calibration_set == 0, run calibration then set calibration...

Hi that sounds great. Where would i find this library?

From another page on this forum havinf searched about spi cs pins that is largely the same topic as here, but i didnt want to hijack someone elses thread.... Say Im using one master teensy (4.1), plus 2 slave teensy's (4.1) and 1 slave ADC all connected to: pin 11 mosi pin 12 miso pin 13...

Thank you KurtE, I think this is going to take a little while to digest, but that's pointed me exactly where i need to be. Regards.

Hi, That largely answers my question. I am using 8 dacs going into multiplexors for CVs for a large synthesizer system. /LDAC sync is not needed. I am aware of the !CS limits and so am using an addressing and buffering system using various logic devices like active low 3 to 8 line decoders...

Hi, Im working on a fairly complex project and one of the things it does is write to a bunch of SPI dacs and read from an SPI adc. The write speed of the spi dacs are rated at 20Mhz clk (although before I realised this, I tested them up to 80Mhz and settled on 48Mhz) but the adc spi bus is...