Search found 82 matches

by chrismas9
Fri Feb 08, 2019 7:40 am
Forum: General Discussion and Questions
Topic: Terminology: upload vs download
Replies: 4
Views: 151

Re: Terminology: upload vs download

The most consistent use is on the Internet where upload and download are with respect to yourself. You always download a movie (to yourself) and upload a web page (from yourself) to a web server.

So you would download a log file from a pyboard and upload a new main.py to it.
by chrismas9
Sat Feb 02, 2019 12:10 am
Forum: The MicroPython pyboard
Topic: CANbus bitrate and frame loss
Replies: 7
Views: 268

Re: CANbus bitrate and frame loss

This may not affect packet loss but I see two hardware issues that may affect reliability. There is no GND connection between the two devices on the bus. Without a GND you rely on the ESD clamp diodes to try and maintain the signals within the common mode range which is not reliable. There is no ter...
by chrismas9
Fri Feb 01, 2019 11:47 pm
Forum: General Discussion and Questions
Topic: Pyboard not working. Red, yellow and blue leds are shining.
Replies: 4
Views: 114

Re: Pyboard not working. Red, yellow and blue leds are shining.

Try the following: 1. Jumper P1 (Boot0) to X15 (3V3) 2. Plug USB into Windows computer. 3. You should get a ding ding noise if USB recognised. 4. Look in device manager. You should see STM32L4 device in DFU mode listed, probably under USB. If that works your STM32 chip and USB port are ok and you sh...
by chrismas9
Tue Jan 29, 2019 10:11 am
Forum: Other Boards
Topic: STM32F3 ports
Replies: 41
Views: 2200

Re: STM32F3 ports

IMO the F3 has been superceded by the F4 and L4. I would not start a new design around an F3. For similar price the F4 or L4 are faster, have more RAM and are better integrated. For example F3 needs 2 transistors and 6 resistors for USB. F4 needs 2 resistors. L4 needs nothing. There is not likely to...
by chrismas9
Tue Jan 22, 2019 12:53 pm
Forum: The MicroPython pyboard
Topic: spi and chip select
Replies: 2
Views: 99

Re: spi and chip select

Yes, you can use any GPIO in SPI master mode and you can have multiple devices on same SPI buss each with their own GPIO CS. SS is only needed in slave mode where it is an input to the SPI block.
by chrismas9
Fri Jan 04, 2019 11:37 pm
Forum: The MicroPython pyboard
Topic: PYBv1.1 V+ range
Replies: 7
Views: 235

Re: PYBv1.1 V+ range

All automotive systems suffer from alternator load dump which generates positive and negative spikes in the +/-60 to 80 V range. If the alternator is supplying 10A to the headlights and you turn them off the 10A keeps flowing, slowly reducing as the field current collapses. This causes the alternato...
by chrismas9
Thu Dec 27, 2018 9:03 am
Forum: The MicroPython pyboard
Topic: Simple Newbie LED Question...
Replies: 2
Views: 102

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: 134

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: 6
Views: 613

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: The MicroPython pyboard
Topic: Avoiding the Cargo Cult: R19 and VBACKUP
Replies: 5
Views: 315

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.