Search found 13 matches

by andreo
Fri Feb 08, 2019 6:05 am
Forum: Pyboard D-series
Topic: Questions and wish list about Pyboard D
Replies: 35
Views: 2009

Re: Questions and wish list about Pyboard D

>>> import gc
>>> gc.collect()
>>> gc.mem_free()
178880
by andreo
Thu Feb 07, 2019 7:51 am
Forum: MicroPython pyboard
Topic: Pyboard D reviews
Replies: 8
Views: 1386

Re: Pyboard D reviews

The pyboard D was presented this week-end at FOSDEM Brussels, and MC-HOBBY was there too.
See https://fosdem.org/2019/schedule/event/ ... rs_python/
there is even a video.
Excellent presentation.
by andreo
Thu Mar 08, 2018 3:01 pm
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter and chuckbook, chuckbook wrote Most likely the buffer op-amp of the port is damaged. This would explain the symptoms. On top of that, my pyboard doesn't behave the same way as when I signalled the problem and is somewhat erratic. After resetting the board and restarting, it seems DAC 2 is g...
by andreo
Wed Mar 07, 2018 11:04 am
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter and chuckbook, I turned output buffering off with DAC_CR = 0x40007400 BOFF2 = 0x00020000 stm.mem32[DAC_CR] = stm.mem32[DAC_CR] | BOFF2 and it worked . See RM0090 Reference manual www.st.com/resource/en/reference_manual/dm00031020.pdf Digital-to-analog converter (DAC) chapter 14 page 433 Bit...
by andreo
Tue Mar 06, 2018 6:36 pm
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter, Some news: just reading the DAC registers with stm.mem32 changed the results !!! the files are in https://www.proximuscloud.be/web/app/share/invite/pijdmt6mbj The 2 signals are (almost) as expected, but DAC 2 seems to use the analog buffer and has a reduced voltage. Only explanation is tha...
by andreo
Tue Mar 06, 2018 9:50 am
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter, The mystery is still there... ( I got the same behavior with the DAC.triangle() function .) It has been a pleasure to have your help and it definitively raised my interest in the pyboard. I'll keep this one with my collectibles, with my old Apple II, a 1983 IBM PC, a prototype 8087... As I...
by andreo
Mon Mar 05, 2018 7:58 pm
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

chuckbook,

These data are in the zip file on https://www.proximuscloud.be/web/app/sh ... 8s7ru3yYNX

Andre
by andreo
Mon Mar 05, 2018 2:47 pm
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter, Here are the results: https://www.proximuscloud.be/web/app/share/invite/8s7ru3yYNX I used a signal with a strong DC component. My good old meter is telling me the same as the scope and the Bitscope meter. Same with only one channel at a time. dma.c is not saying more than dac.c. I'll buy a...
by andreo
Mon Mar 05, 2018 10:33 am
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi Peter, Sorry about that misleading sentence: I have only one pyboard. But as it behaves always the same way, I can still work with it. I spent all the morning changing parameters, 8 to 12 bits, all available timers for DAC,... and reading dac.c. Same results. But using DAC.write , instead of writ...
by andreo
Sun Mar 04, 2018 6:02 pm
Forum: MicroPython pyboard
Topic: opposite polarities on the 2 DACs
Replies: 21
Views: 7521

Re: opposite polarities on the 2 DACs

Hi pythoncoder, Thanks a lot for your answer. Surprising behavior from my pyboard... When I used your code for the first time, it worked as expected. A few minutes later, I got back the same inverted signal, and I couldn't get your result anymore. I did reset fully the filesystem, working only from ...