Search found 1522 matches

by Pito
Sun Oct 15, 2017 12:26 pm
Forum: Custom design boards
Topic: Alternative BluePill sized F4
Replies: 14
Views: 176

Re: Alternative BluePill sized F4

indeed good idea :) Do use a larger package with Vdd regulator (ie SOT-223 or Dpack - a package with a heatsink fin) - with large copper around/beneath the heatsink fin. Use a lot of vias to thermally connect the top/bottom copper. Read the chapter 10.1. carefully: http://www.ti.com/lit/ds/symlink/...
by Pito
Sun Oct 15, 2017 12:00 pm
Forum: Custom design boards
Topic: Alternative BluePill sized F4
Replies: 14
Views: 176

Re: Alternative BluePill sized F4

Heat around the voltage regulators. You have got a large gnd plane beneath them, but you do not have any vias for a thermal connection to that plane (the heatsink). Calculate the temperature of the Vdd chip (look for the topic I posted few weeks back). That sot23 package will smoke with 5V input and...
by Pito
Sun Oct 15, 2017 11:47 am
Forum: Custom design boards
Topic: Alternative BluePill sized F4
Replies: 14
Views: 176

Re: Alternative BluePill sized F4

1. use an 800mA voltage regulator for Vdd
2. do use more vias (heat, grounding)
3. wait on stm32H743/753 in 100pin flatpack
by Pito
Thu Oct 12, 2017 11:33 am
Forum: General discussion
Topic: Power LED questions
Replies: 10
Views: 210

Re: Power LED questions

The aprox. current taken by an LED is following (3.3V power voltage, R is the series resistor): 1. Red LED I = (3.3V - 1.7V) / R 2. Yellow, Green LED I = (3.3V - 2.0V) / R 3. Blue, White LED I = (3.3V - 3.0V) / R Example: Green LED and 500ohm resistor I = (3.3V - 2.0V) / 500 = 2.6mA From my measurem...
by Pito
Wed Oct 11, 2017 2:40 pm
Forum: General discussion
Topic: [SOLVED] pin state Hi-Z (floating)
Replies: 2
Views: 80

Re: pin state Hi-Z (floating)

Set the pin to INPUT:

Code: Select all

pinMode(PC7, INPUT);
by Pito
Tue Oct 10, 2017 1:43 pm
Forum: General discussion
Topic: "bit bang" SPI pins STM32F1
Replies: 23
Views: 438

Re: "bit bang" SPI pins STM32F1

Set/Clear GPIO pins: // Set A6, A7, A15 // digitalWrite(PA6, HIGH); // digitalWrite(PA7, HIGH); // digitalWrite(PA15, HIGH); GPIOA->regs->BSRR = 0b1000000011000000; // Clear B6, B7, B15 // digitalWrite(PB6, LOW); // digitalWrite(PB7, LOW); // digitalWrite(PB15, LOW); GPIOB->regs->BRR = 0b10000000110...
by Pito
Mon Oct 09, 2017 3:15 pm
Forum: General discussion
Topic: "bit bang" SPI pins STM32F1
Replies: 23
Views: 438

Re: "bit bang" SPI pins STM32F1

Comment out all delays if you need more speed (bitBangedSPI.cpp): // clock high digitalWrite (sck_, HIGH); // delay between rise and fall of clock delayMicroseconds (delayUs_); // clock low digitalWrite (sck_, LOW); // delay between rise and fall of clock delayMicroseconds (delayUs_); } // end of fo...
by Pito
Mon Oct 09, 2017 10:35 am
Forum: General discussion
Topic: "bit bang" SPI pins STM32F1
Replies: 23
Views: 438

Re: "bit bang" SPI pins STM32F1

In order to save 4 tons of your time: https://github.com/nickgammon/bitBangedSPI I've been using it with max7219 and BluePill and it works. Something like this (not tested this way, you have to spend some pounds of time to elaborate): // bitBangedSPI (const int mosi, const int miso, const int sck, c...
by Pito
Mon Oct 09, 2017 10:12 am
Forum: General discussion
Topic: "bit bang" SPI pins STM32F1
Replies: 23
Views: 438

Re: "bit bang" SPI pins STM32F1

You may bitbang any pins with bitbanged SPI.
by Pito
Sat Oct 07, 2017 6:02 am
Forum: General discussion
Topic: i2c overclocking up to 1Mhz
Replies: 13
Views: 255

Re: i2c overclocking up to 1Mhz

There are such I2C slaves, ie ADS11xx - up to 3.4MHz clock (and there are other chips sure). They communicate 100/400kHz (Standard/Fast Speed) from init(), but the High-Speed mode (up to 3.4MHz) needs to be activated (a command sent to the master). It seems you have to be able to change the clock on...