Time keeping with utime

[priis]

Some days ago I bought an esp32 and a pysense board. After several hours of struggling I can now read all the sensors of the pysense board.
However, for the time keeping I would like to measure time in seconds with at least one decimal.
I tried
start=time.ticks_ms()
followed by
print( time.ticks_diff(start, time.ticks_ms()))

only resulting in the following error message (and a lot more garbage):

Guru Meditation Error of type LoadProhibited occurred on core 0. Exception was unhandled.
Register dump:
PC : 0x400ed168 PS : 0x00060f30 A0 : 0x800fd348 A1 : 0x3ffc6120
A2 : 0x00000000 A3 : 0x00060f23 A4 : 0x00060f20 A5 : 0x00000002
A6 : 0x0000002a A7 : 0x3ffc62f0 A8 : 0x00000000 A9 : 0x3ffc6110
A10 : 0x00000000 A11 : 0x00060f23 A12 : 0x00060f20 A13 : 0x00000000
A14 : 0x0000000a A15 : 0x3ffc62d0 SAR : 0x0000000c EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000000 LBEG : 0x4000c46c LEND : 0x4000c477 LCOUNT : 0x00000000

Backtrace: 0x400ed168:0x3ffc6120 0x400fd348:0x3ffc6140 0x400ef3d9:0x3ffc6160 0x400eb9d8:0x3ffc6180 0x400eba40:0x3ffc61a0 0x400f75b8:0x3ffc61c0 0x400ef48b:0x3ffc6260 0x400eb9d8:0x3ffc62f0 0x400eba05:0x3ffc6310 0x400d948e:0x3ffc6330 0x400d972f:0x3ffc63d0 0x400d885f:0x3ffc6410

================= CORE DUMP START =================
9CEAAAoAAABsAQAA
QET8P2Bg/D+oZfw/
AGL8P0Bl/D+mswIAUEH8P1BB/D9ARPw/SEH8PxQAAAAAAAAAAAAAAEBE/D8AAAAA
BQAAAKxF/D9NaWNyb1B5AAAAAAAAAAAAAAAAAKhl/D8AAAAAIQAGAAUAAAABAAAA
AAAAAAxt/D8AAAAAAAAAAAAAAACYZPk/eGT5P1hk+T8AAAAAAAAAAAEAAAAAAAAA
pM5CPwAAAABIHQBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAA==



I also tried utime with no better results.
How can I get an accurate time keeping with micropython?

[Roberthh]

That seems to be the wrong forum for your questions, since pysense is a Pycom product. You may better ask at forum.pycom.io.
Besides that, it is not clear why ticks_ms and ticks_diff should cause a core dump. Please post also you firmware version and the ESP32 board model.

[priis]

I use esp32-20180920-v.1.9.4-560-g185716514.
I thought that micropython is micropython but I have seen so many strange errors (some times my programs run perfectly, other times the very same programs crash with mysterious error messages). So now I have the suspicion that I use the wrong firmware for my esp32 pycom wipy3.0 wifi Bluetooth module. But what is then the correct firmware? And where can I find it?

[jickster]

I use esp32-20180920-v.1.9.4-560-g185716514.
I thought that micropython is micropython but I have seen so many strange errors (some times my programs run perfectly, other times the very same programs crash with mysterious error messages). So now I have the suspicion that I use the wrong firmware for my esp32 pycom wipy3.0 wifi Bluetooth module. But what is then the correct firmware? And where can I find it?

http://micropython.org/download#esp32

[priis]

... Sorry, my firmware is
MicroPython v1.8.6-621-g17ee404e on 2017-05-25; WiPy with ESP32

[jickster]

... Sorry, my firmware is
MicroPython v1.8.6-621-g17ee404e on 2017-05-25; WiPy with ESP32

But what’s your hardware?


Sent from my iPhone using Tapatalk Pro

[pythoncoder]

If you're running PyCom hardware you should run their firmware: MicroPython is customised to specific hardware platforms. You'll get more knowledgeable answers to questions on PyCom kit if you raise them in the PyCom forum.

[priis]

And how to flash it?
I tried ESP8266 flasher but that didn't work.
Next, I tried the following from a DOS terminal window:
esptool.py --chip esp32 --port COM7 write_flash -z 0x1000 esp32-20180511-v1.9.4.bin
but I get an error message:
epstool: error: argument operation: invalid choice: 'esp32' (choose from 'load_ram' ...).

What is the exact syntax?

[Roberthh]

You should get a recent copy of esptool.py, e.g. from this place: https://github.com/espressif/esptool

[priis]

Thanks, I have done that. But again, what is the exact syntax of the esptool command?
I have tried several variations of
esptool.py --chip esp32 --port COM7 write_flash -z 0x1000 esp32-20180927-v1.9.4-584-g57a7d5be9.bin
- none of them works.