Search found 101 matches

by chrismas9
Sat Oct 15, 2016 2:13 pm
Forum: General Discussion and Questions
Topic: Pyboard noise
Replies: 21
Views: 6904

Re: Pyboard noise

Hi Bob, @roberthh and @pythoncoder give good advice about grounding and using a star ground. This is not always enough. It helps to understand all the ways noise can get into sensitive circuits. I do a lot of mixed signal design and I will explain how I analyse noise sources and optimise PCB layouts...
by chrismas9
Sun Aug 28, 2016 1:41 am
Forum: MicroPython pyboard
Topic: connecting pyboard to CAN BUS
Replies: 45
Views: 16661

Re: connecting pyboard to CAN BUS

I use the Microchip MCP series DIP CAN transceivers regularly with STM32. They are a 5V device but fully compatible with 5V tolerant 3.3V MCU's. No level translator is required. The transmitter input requires <0.8V and >2V for logic 0 and 1 respectively which the STM32 can do. The receiver output gi...
by chrismas9
Sun Aug 28, 2016 1:26 am
Forum: MicroPython pyboard
Topic: Unstable value when use analog imput on pyboard v 1.1
Replies: 3
Views: 1737

Re: Unstable value when use analog imput on pyboard v 1.1

A good test would be to run the Pyboards off 3 or 4 Alkaline cells (4.5V - 6V). If the analog results are good for both boards your power supply is noisy. Pybv1.1 requires slightly higher voltage on Vin and may be more susceptible to switching spikes from a switch mode power supply. The changes to t...
by chrismas9
Sun Aug 28, 2016 1:12 am
Forum: MicroPython pyboard
Topic: many VIN and GND pins
Replies: 2
Views: 1178

Re: many VIN and GND pins

The multiple PWR & GND pins are for convenience of connecting multiple things to the board. These include: - two half size skins, eg AMP and LCD, - as Dave said; four hobby servo motors, - four analog inputs with their own quiet GND pin, - main power from battery or power supply, - backup battery fo...
by chrismas9
Sun Jun 05, 2016 7:44 am
Forum: MicroPython pyboard
Topic: SD Card not working on v1.1 HW?
Replies: 6
Views: 2270

Re: SD Card not working on v1.1 HW?

I always use Saferinse after Safewash when I do aqueous cleaning and haven't had any residue problems. Alternatively I have found hot water rinsing and compressed air drying works well. It depends on how good your tap water is.
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by chrismas9
Sun Mar 06, 2016 12:19 am
Forum: Other Boards
Topic: Clock configuration and SYSCLK for STM411RE
Replies: 2
Views: 1139

Re: Clock configuration and SYSCLK for STM411RE

I believe you can't derive the 48MHz USB clock when you set the PLL to 100 MHz
by chrismas9
Sun Jan 31, 2016 3:29 am
Forum: ESP8266 boards
Topic: MicroPython on ESP8266 Kickstarter
Replies: 91
Views: 40393

Re: MicroPython on ESP8266 Kickstarter

Congratulations, you made the top 25 on Kicktraq today :D You deserve it for all the hard work you put into MicroPython.
by chrismas9
Fri Jan 29, 2016 3:19 pm
Forum: Other Boards
Topic: Porting uPy to STM32F446
Replies: 3
Views: 1881

Re: Porting uPy to STM32F446

I guess I am most interested specifically in the STM32F446RET6 The F446 does not have PB11. It requires another cap in the pin for the core voltage regulator. The F411 is the same. Hence you might find it easier to modify pyblite which uses F411. You will loose I2C from pins Y9 and Y10 because the ...
by chrismas9
Wed Dec 16, 2015 11:40 pm
Forum: Development of MicroPython
Topic: Micro Python development wish list
Replies: 52
Views: 19553

Re: Micro Python development wish list

MTP does not allow file editing, only transfer or open read only. Verified with Android 4 and Windows Phone 8 connected to WIN7 and WIN8. Differences between MSC (memory stick) and MTP (phone) under Windows. 1. Phone does not mount with a drive letter. 2. Windows explorer does not have "New --> Text...
by chrismas9
Wed Dec 16, 2015 12:46 pm
Forum: Development of MicroPython
Topic: Micro Python development wish list
Replies: 52
Views: 19553

Re: Micro Python development wish list

I would like to see a more robust file system and host file sharing than FATFS and MSC. A journalling, wear levelling file system is much more robust. The first step would be to replace MSC which accesses sectors with a file sharing or transfer protocol. Henrik Solver suggested MTP (Media Transfer P...