Search found 147 matches

by chrismas9
Wed Nov 13, 2019 1:10 pm
Forum: Development of MicroPython
Topic: [Solved]screen /dev/ttyACM0 on STM32L4R9IDISC
Replies: 17
Views: 1628

Re: screen /dev/ttyACM0 on STM32L4R9IDISC

The board has two USB connectors, one on top and one on bottom side. You will need two USB cables to get USB REPL to work. You need power into STlink port. It can be from phone charger or PC. The second cable must go from USB port labelled USB FS OTG to PC. You should then see. Virtual com port on y...
by chrismas9
Tue Nov 12, 2019 10:41 pm
Forum: General Discussion and Questions
Topic: CAN on STM32F4xx
Replies: 12
Views: 1288

Re: CAN on STM32F4xx

I used a similar CN transceiver from Microchip. Yours needs dual supplies and enable, mine had slope control. Shouldn't make any difference as long as all 8 pins are connected. I presume you are using STM32F439 port as a starting point for your board. Are you using the same pins as specified in mpco...
by chrismas9
Tue Nov 12, 2019 10:08 pm
Forum: Development of MicroPython
Topic: [Solved]screen /dev/ttyACM0 on STM32L4R9IDISC
Replies: 17
Views: 1628

Re: screen /dev/ttyACM0 on STM32L4R9IDISC

Have you enabled USB? If so short BOOT0 to 3V3 and plug USB into PC. Use the USB OTG-FS port with power to the STlink port. The board should appear as STM32 in DFU mode (or something similar, not sure how it appears in Linux). Thus will verify your USB. If USB is enabled your REPL will be on USB vir...
by chrismas9
Tue Nov 12, 2019 5:31 am
Forum: General Discussion and Questions
Topic: CAN on STM32F4xx
Replies: 12
Views: 1288

Re: CAN on STM32F4xx

I have used that test script on several Nucleo boards. What board and MicroPython version are you using? If it's custom post your mpconfigport.h What CAN transceivers are you using? Are they powered from 3.3V or 5V? What is the logic 1 input threshold on the MCU side? TTL compatible parts are 2 to 2...
by chrismas9
Mon Nov 11, 2019 12:47 am
Forum: General Discussion and Questions
Topic: CAN on STM32F4xx
Replies: 12
Views: 1288

Re: CAN on STM32F4xx

Do you have a termination resistor on the CANbus? CAN tranceivers are open collector and won't work without a termination resistor to define the recessive state. If you just connect two tranceivers together without a bus a single 50 to 100 ohm resistor should work. Here is the test script I used to ...
by chrismas9
Mon Nov 04, 2019 5:26 am
Forum: Other Boards
Topic: nucleo F401RE cannot import name Servo
Replies: 7
Views: 1094

Re: nucleo F401RE cannot import name Servo

The easiest way to build MicroPython is to load Ubuntu from the Microsoft Store. Type bash in the search box to launch a Ubuntu bash shell using WSL (Windows subsystem for Linux). Then follow the MicroPython readme for building under Ubuntu. I use Tortoise Git and a Windows programmer's editor to ma...
by chrismas9
Sun Nov 03, 2019 10:15 am
Forum: General Discussion and Questions
Topic: Shift Register PWM
Replies: 6
Views: 1019

Re: Shift Register PWM

If the supply voltage is less than the reverse breakdown voltage of the LEDs you may not need individual transistors on the shift register outputs, just one transistor or MOSFET on the common GND side of the LEDs driven by a PWM signal. If you only want say 16 levels of brightness you may be able to...
by chrismas9
Sun Nov 03, 2019 6:46 am
Forum: MicroPython pyboard
Topic: LiPo powering and charging
Replies: 2
Views: 579

Re: LiPo powering and charging

There is no on board Lipo charger and no connector pins to add one without soldering directly to a diode or IC pad. Q1 acts as a diode. When Vbus is absent the Pyboard is powered from the main battery (VBAT). Initially power goes through the body diode. If VBUS is disconnected resistor R22 will turn...
by chrismas9
Thu Oct 24, 2019 9:39 am
Forum: General Discussion and Questions
Topic: Is there some successful MicroPython products?
Replies: 6
Views: 966

Re: Is there some successful MicroPython products?

I use MicroPython in commercial products. I haven't had a problem with performance. MicroPython has interrupt and timer call backs and cooperative multi tasking (uasyncio) to help get good response to time critical events. If you want Wi-Fi or BLE the ESP8266 and ESP32 run MicroPython or C/ASM at th...
by chrismas9
Sun Oct 13, 2019 10:15 am
Forum: Other Boards
Topic: STM32F103C8T6 Data Acquisition board
Replies: 3
Views: 682

Re: STM32F103C8T6 Data Acquisition board

STM32F103C8T6 only has 64K flash. That's not enough. The smallest working port for STM32 is L073 at 192K. I have managed to get it down to 149K but I gave up trying to get to 128K.