MicroPython Forum (Archive)

well, i've made some progress sending in 512 byte chunks from the host and using the following program to recv, I am receiving 1 million bytes + # from teensy receive_test /dev/ttyACM0 # recv is blocking (timeout 5000ms), read is not import pyb msg = 'nothing' sw = pyb.Switch() sw.callback(lambda:ua...

I have measured USB performance (latency, read rate) on various MCU's (teensy, DUE, maple, UNO) using the framework described at http://www.pjrc.com/teensy/benchmark_usb_serial_receive.html Using the same host harness (on Ubuntu laptop), I used the following pyboard program to measure latency # from...

dang, I keep forgetting all things in firmware directory are not in firmware .... copied sdcard.py, and things are better ... working on OSError: no SD card Edit: I get the "no SD card" the first time i do >>> sd = sdcard.SDCard(pyb.SPI(1), pyb.Pin.board.X5) if i do that again, then it works and i c...

Using a standalone SD breakout board, I confirmed quiescent SD currents of 100ua (varies depending on make and mode of SD or microSD) .... The pyboard supports external SD cards in SPI mode: I must be having a senior moment, I tried to get the SPI SD driver to work using hint in firmware source driv...

there was more discussion on http://forum.micropython.org/viewtopic.php?t=598
including adjusting the frequency using calibration registers ...

your "10 seconds per 24 hours" is 115ppm, about what others have been measuring.

thanks, I didn't realize you could directly access the special ADC channels. I edited my whining earlier in this thread.

I get 29ua in standby mode on my pyboard IF the microSD card is not inserted. if I insert the microSD card, the current climbs to 190ua. Is this from the quiescent current of a microSD card? I assume the media sense switch on PA8 (in PULLUP mode) is disabled (not drawing current) in standby. if i re...

moose wrote:Is there any way to reduce the amount of time and/or current required to come out of pyb.standby()? I ran a do-nothing program to determine how much current (actually, charge) is consumed during the bootup after pyb.standby():

@moose what did you use to measure/plot current?

How would you use the information about the total number of GCs? A way that might work for you is to disable auto GC using gc.disable() then force a GC yourself in your main loop with gc.collect(). Then just increment your own counter. GC is a mystery to me, and the fact that it consumes more than ...

Ah, looks likes the new os.uname() does what I needed ... >>> import os >>> os.uname() (sysname='pyboard', nodename='pyboard', release='1.4.2', version='v1.4.2-16-gfd787c5-dirty on 2015-04-23', machine='PYBv1.0 with STM32F405RG') thanks. my other wish is that gc_collect() keep a running count of the...