Search found 91 matches

by chuckbook
Thu Jan 03, 2019 9:20 am
Forum: MicroPython pyboard
Topic: LCD example library? (it's for a birthday present)
Replies: 4
Views: 290

Re: LCD example library? (it's for a birthday present)

Did you have a look at https://www.youtube.com/watch?v=OOz9U_YdstM ?
If there is a demo that matches your needs I will provide you with that code.
by chuckbook
Thu Jan 03, 2019 9:16 am
Forum: MicroPython pyboard
Topic: Save data on power down
Replies: 14
Views: 717

Re: Save data on power down

A CR2032 provides ~220mAh capacity. Assuming VBAT consumption is ~10 µA this would give ~3 years of operation.
At 1/256 s RTC tick frequency typical Pyboard VBAT consumption is more like 1.5 µA. This will result in a shelf life of >10 years.
With RTC disabled VBAT is << 1 µA.
by chuckbook
Wed Jan 02, 2019 4:01 pm
Forum: MicroPython pyboard
Topic: Save data on power down
Replies: 14
Views: 717

Re: Save data on power down

With a Pyboard either RTC backup registers or static backup RAM (4kByte) can be used for such tasks.
For a simple ODOmeter something like:

Code: Select all

import stm
stm.mem32[stm.RTC+stm.RTC_BKP9R] += 1
would do the job.
As long as VBAT is powered the content of RTC_BKP9R will be valid.
by chuckbook
Mon Dec 03, 2018 11:55 am
Forum: MicroPython pyboard
Topic: Is there a way to increase RAM?
Replies: 7
Views: 526

Re: Is there a way to increase RAM?

There are 192kB of SRAM on the F405. A PYBV11 shows: >>> micropython.mem_info(1) stack: 484 out of 15360 GC: total: 102656, used: 1440, free: 101216 64 kB SRAM is used for filesystem cache and ~30kB SRAM for static variables and stack (depending on build options). Using 64k as file system cache is a...
by chuckbook
Tue Nov 27, 2018 4:36 pm
Forum: Drivers for External Components
Topic: pinout for the Colour LCD skin LCD160CRv1.0H
Replies: 10
Views: 722

Re: pinout for the Colour LCD skin LCD160CRv1.0H

Note that LCD160CR needs to be turned on by pulling X4 high. It's also worth mentioning that LCD160CR supports UART communication, but there is no HW flow control. Minimal interface in I2C mode is: VIN, GND, SCL, SDA and X4 to turn on the display. Instead of X4 the 3.3V input on the 10-pin connector...
by chuckbook
Wed Nov 07, 2018 6:46 pm
Forum: General Discussion and Questions
Topic: javascript time stamp to python date
Replies: 1
Views: 153

Re: javascript time stamp to python date

Use:

Code: Select all

UNIX_TIME = 946681200
mpy_ts = js_ts - UNIX_TIME*1000
by chuckbook
Sat Oct 27, 2018 4:15 pm
Forum: MicroPython pyboard
Topic: Camera integration
Replies: 13
Views: 6225

Re: Camera integration

Don't worry to use high UART baudrates on pyboard. Most of the time 115200 baud are used. We also successfully used baudrates of up to 921000.
by chuckbook
Fri Oct 19, 2018 11:41 am
Forum: Other Boards
Topic: persistent memory?!?
Replies: 6
Views: 477

Re: persistent memory?!?

On a pyboard there are 4Kbytes of NVRAM. It survives a power cycle as long as VBACK is active.
by chuckbook
Thu Aug 30, 2018 9:49 am
Forum: MicroPython pyboard
Topic: SPI initialization not working
Replies: 2
Views: 312

Re: SPI initialization not working

Note that STM32 SPI cannot provide all baudrates. In fact if a specific baudrate is requested, MPY selects the available baudrate <= requested baudrate. Also note that available baudrates vary with SYSCLK frequency. All of the above is only true for HW SPI, SW SPI might give finer granularity at low...
by chuckbook
Sat Aug 25, 2018 4:07 pm
Forum: General Discussion and Questions
Topic: Calculation benchmark of micropython in different hardware
Replies: 14
Views: 1267

Re: Calculation benchmark of micropython in different hardware

pythoncoder wrote:
Sat Aug 25, 2018 4:23 am
chuckbook wrote:
Fri Aug 24, 2018 11:10 am
...without warranty: 216M, 1.547, 1.721, 2.839, 4.116 :-)
Impressive figures.

But to quote from Basil Fawlty
where did you get that?
;)
To quote from Dr. Franklyn
I would love to tell you, but then, of course...
;-)