Search found 98 matches

by chrismas9
Mon Jun 03, 2019 11:12 pm
Forum: General Discussion and Questions
Topic: PyBoard Timer Question
Replies: 7
Views: 264

Re: PyBoard Timer Question

If you can't find a software solution you could add an analog switch to select the input (PWM) or output waveform to the same ADC. Just stream the ADC as fast as you want and switch to output after enough time to capture some input cycles. Knowing the sample rate you can calculate the average phase ...
by chrismas9
Tue May 21, 2019 4:11 am
Forum: Other Boards
Topic: [STM32F412RG] porting micropython flash memory problems
Replies: 5
Views: 138

Re: [STM32F412RG] porting micropython flash memory problems

I recently did the F413 port. Unless you need Ethernet consider using it instead, or try using it as a starting point instead of F411. It needed a few changes to the port source files, not just a custom config. For example the generic F4 startup file does not support some interrupt vectors like SPI ...
by chrismas9
Tue May 21, 2019 3:46 am
Forum: Other Boards
Topic: STM32F401CCU6 SUPPORT
Replies: 3
Views: 144

Re: STM32F401CCU6 SUPPORT

MicroPython runs on the L432 with 256k/64k. Have a look at it's linker script and mpconfigboard.h. You will see quite a few features turned off, eg pyblegacy, to make it fit. You might be able to have a 16k filesystem. There is room for 26k in L432 but I doubt you will get 32k. You will need 16k ram...
by chrismas9
Thu Apr 25, 2019 4:50 am
Forum: Hardware Projects
Topic: How to expand the size of spiflash?
Replies: 9
Views: 309

Re: How to expand the size of spiflash?

The F411 does not have a hardware QSPI controller. You will need to use 1 bit SPI mode with hard or soft SPI. Have a look at STM32L476DISC port for example.
by chrismas9
Sun Apr 21, 2019 4:14 am
Forum: General Discussion and Questions
Topic: Safety of KY-019 relay
Replies: 4
Views: 150

Re: Safety of KY-019 relay

All domestic room heaters have a tilt switch and thermal cutoff that is independent of the thermostat. I suggest an independent cutout that does not rely on software. A suitable thermal cutoff is something like Digi-Key 317-1127-ND. These are available with different trip temperatures. It must be cl...
by chrismas9
Sat Apr 20, 2019 7:03 am
Forum: MicroPython pyboard
Topic: code in internal flash and mounting sd card as usb mass storage
Replies: 7
Views: 237

Re: code in internal flash and mounting sd card as usb mass storage

Have you considered using frozen byte code? The source code won't be on the system at all and will be better protected than hiding it on an non visible drive. To protect code on a non visible drive you would also have to disable REPL to stop people running their own code to read yours.
by chrismas9
Tue Apr 16, 2019 11:39 pm
Forum: MicroPython pyboard
Topic: Will 3.6 volts fry my pyboard
Replies: 2
Views: 121

Re: Will 3.6 volts fry my pyboard

Not all STM32 pins are 5V tolerant. The DAC pins PA4 and PA5 are not 5V tolerant even in digital IO mode. On some STM32s other pins are not (sometimes PA3 and maybe more). Always check the data sheet. Most analog pins, eg PA0, are 5V tolerant at reset and in digital IO mode. In ADC mode the inputs a...
by chrismas9
Tue Apr 16, 2019 11:25 pm
Forum: General Discussion and Questions
Topic: Season of Docs proposal for MicroPython
Replies: 9
Views: 367

Re: Season of Docs proposal for MicroPython

That's a great idea. I have a couple of suggestions for the library documentation. 1. Where there is a port specific additional feature add a hyperlink in the common docs to the port specific docs. That will allow you to work from the common docs without having to check the port specific docs every ...
by chrismas9
Sun Apr 14, 2019 1:22 am
Forum: General Discussion and Questions
Topic: Other Micropython forums
Replies: 3
Views: 222

Re: Other Micropython forums

High activity is not necessarily a good sign. I use a commercial PCB CAD package and its forum is alive with activity - nearly all complaints about bugs and feature changes. I find MicroPython just works and is easy to understand. I don't need to ask for help often. What is important is that there a...
by chrismas9
Sun Apr 14, 2019 1:11 am
Forum: General Discussion and Questions
Topic: best practice for erasing /flash after updating firmware
Replies: 2
Views: 122

Re: best practice for erasing /flash after updating firmware

Usually updates preserve the filesystem. However some updates affect the filesystem and you need to do a filesystem reset using the USR switch at reset. Hold down USR and press RST. After releasing RST the green and yellow LEDs will count in binary. Release USR at 3 - both LEDs on. The red LED will ...