If you're reading serial via USB — which I take to mean you are using USB serial adapters with a USB type A plug on one end and something like an RS232 9-pin connector on the other — the Pi3 UART change does not affect you. If this is the case, it might be better to start another thread to ask for help with it.Max_G wrote:I am gob smacked... just bought 2 Pi3 to run a python script reading serial via USB and it does not work...
Well put... thanks! This clearly demonstrates that I should not be talking about things I do not understand.PhilE wrote:It's either because ttyAMA0 is the more capable UART with larger FIFOs and a clock which is immune to core frequency changes, or because we hate you - pick whichever suits your world view.
In those days you were hitting hardware interrupts directly, and were running a single-tasking OS barely capable of network access. Linux and Unix does make serial port access more complex because you're abstracted away from the hardware. You can't guarantee realtime I/O any more, and too much of the DOS-age code relied upon that.Mane wrote:"In the good old days" PCs had such and they were accessible. Nope today. The USB -RS232 converters just make a simple thing over complicated
Out of interest, how were you connecting the 3.3V micro to the laptop, and did you try the same method with the Pi?scootergarrett wrote:I have a micro controller sending the alphabet one letter a second. My laptop with minicom works fine but when I use a Pi3 with Jessie and /dev/ttyS0 the pi seems to miss a lot of data.
Do you have a getty (serial login manager) running? If getty and minicom are both reading from the same port, it is non-deterministic which one gets any particular byte. Getty echoes, because it is intended for remote interactive use.I don't know why the pi is sending info back to the microcontroller
I addedDo you have a getty (serial login manager) running?
Code: Select all
sudo systemctl stop serial-getty@ttyS0.service
Of course, it will boot faster. You're not starting and stopping a pointless (for you) service.scootergarrett wrote:I did see the disable option, what would be the advantage? Boot up faster? It's work now so I'm happy