Search found 106 matches

by chrismas9
Thu Dec 27, 2018 9:03 am
Forum: MicroPython pyboard
Topic: Simple Newbie LED Question...
Replies: 2
Views: 244

Re: Simple Newbie LED Question...

There is a good example in the signal class of the machine library: http://docs.micropython.org/en/latest/library/machine.Signal.html This refers to active high and active low LEDs. Active high LEDs have the Anode connected to the MCU pin directly or through a resistor. Active low LEDs have the cath...
by chrismas9
Sun Nov 25, 2018 6:52 am
Forum: General Discussion and Questions
Topic: RS-485 flow control for Modbus RTU
Replies: 1
Views: 417

Re: RS-485 flow control for Modbus RTU

What is your target MCU? The STM32L4 series (L476, etc) have built in Driver Enable mode for the RTS pin. It's not supported in MicroPython but you could probably enable it with direct MCU register access.
by chrismas9
Sun Oct 28, 2018 9:53 am
Forum: General Discussion and Questions
Topic: Windows development enviroment/IDE?
Replies: 8
Views: 1127

Re: Windows development enviroment/IDE?

Try Thonny. It has an editor with run button that loads scripts directly to ram without needing to write to flash. It has a REPL window with auto detect of serial and USB-serial ports. When you finish debugging you can download your script to flash. It installs Cpython by default but comes with plug...
by chrismas9
Mon Oct 01, 2018 1:47 am
Forum: MicroPython pyboard
Topic: Avoiding the Cargo Cult: R19 and VBACKUP
Replies: 5
Views: 534

Re: Avoiding the Cargo Cult: R19 and VBACKUP

Under certain startup conditions the STM32 can momentarily connect Vbat to Vdd. The resistor protects the battery when this happens.
by chrismas9
Sun Sep 30, 2018 4:45 am
Forum: MicroPython pyboard
Topic: Documentation for pyboard v1.1?
Replies: 4
Views: 533

Re: Documentation for pyboard v1.1?

U2 is the 8 pin chip you refer to. It is an MCP1703 in DFN8 package with thermal pad (pin 9 on the schematic). When you click on U2 in Acrobat Reader it shows the correct manufacturer and Digikey part numbers for the DFN8 package. See screen shot attached.
by chrismas9
Thu Sep 13, 2018 12:25 pm
Forum: MicroPython pyboard
Topic: Updating firmware on a PyBoard
Replies: 8
Views: 1092

Re: Updating firmware on a PyBoard

If you reset the Pyboard the USB virtual com port disappears and comes back. Putty does not recover. With Putty you have to disconnect before the reset and reconnect after the port is re-established. I use Hyperterminal. It usually lets you disconnect and reconnect after a reset. I don't know of any...
by chrismas9
Mon Sep 10, 2018 12:22 pm
Forum: MicroPython pyboard
Topic: Updating firmware on a PyBoard
Replies: 8
Views: 1092

Re: Updating firmware on a PyBoard

Since you are talking about COM1 I suspect you are using Windows. Download the DfuSE demo from ST.com and use it to program the STM32 over USB. There is more information here: https://micropython.org/resources/Micro-Python-Windows-setup.pdf Windows 10 has built in drivers so ignore the driver sectio...
by chrismas9
Mon Sep 10, 2018 12:01 pm
Forum: MicroPython pyboard
Topic: Avoiding the Cargo Cult: R19 and VBACKUP
Replies: 5
Views: 534

Re: Avoiding the Cargo Cult: R19 and VBACKUP

This is a UL requirement for use of coin cells. See this post: https://www.embedded.com/electronics-blogs/break-points/4430499/UL-coin-cell-requirements- Pyboard uses the second circuit with two diodes and a resistor where the two diodes are replaced by an active MOSFET changeover switch in the STM3...
by chrismas9
Thu Aug 23, 2018 5:26 am
Forum: General Discussion and Questions
Topic: Best way to debug with no USB
Replies: 6
Views: 561

Re: Best way to debug with no USB

The ESP8266 does not have USB either so various programs have been developed to download scripts to flash over the REPL serial port using raw REPL mode.

Dave Hyland's rshell is well regarded but there are others like mu, Ampy, etc