The wiki for pills is not very detailed.
A1. Not for now...
This post helps. Use google search site:stm32duinoforum.com/forum
Q2. Is there any reference website or blog which could act as a good dictionary for a newbie like me?
http://www.gammon.com.au/forum/bbshowpo ... pic_id=123 is very helpful. Any similar blog or website concerning more about Bluepills?
A2. Not for now.
But I've found https://github.com/rogerclarkmelbourne/ ... STM32/wiki check the list on the right.
This wiki uses BP for an example many times.
Q3. What's the VB used for? Is it not the same as VRAW on Arduino boards? What's its voltage safe range?
I got 2 STM32F103C8 Bluepills. They look like Arduino nano. But what confuses me is the VB port (means VBattery).
I read the pin map gif. It shows that VB port can't stand a voltage as high as 5v (not a black dot, it's a white dot or circle).
I saw a regulator on the back of Bluepill which looks like the one on Arduino Pro Mini's which could be 3.3v(5v)~12v. But I'm not a hardware expert.
No VRAW pin, it accepts 5v input by USB and the 5v pin. If both are used together, may cause problems.This meant to be used with the RTC peripheral so you can power down the device but maintain the RTC settings. Search this site for RTC V Battery and read about the warnings about it. You want to use this only with 3v3. Feeding it anything else will blow your stm32 chip.
The VB pin is not a main power input pan. Cause couple of days later, I got some bigger boards with a tiny battery onboard, I think the PB's VB pin may be used like that way.Read the link I posted above about powering the device. You can either power it via the USB or the 5v pin but not both at the same time. This 5v input goes to a tiny 3.3v regulator (I do mean tiny so don't over load the 3.3v pins too much). The board it'self runs on 3.3v but can tolerate 5v intputs on some pins.
Q4. What's the right way to use 128kb flash? Just open a sketch of 100kb with the STM32F103C8 64kb option selected, then simply click upload?
The wiki says STM32F103C8 could have 128kb flash just like STM32F103CB, but there could be an exception case.
So how to set the chip option to make it 128kb? Should I choose the STM32F103CB 128k option?
I noticed when choosing STM32F103C8 64kb the upload log always display a flash of 128k.
Q5. What's the internal pull-up resistor's value of the Bluepill and total minimize pull-up resistor for I2C?Just select 128k option and use it. I don't think anyone has a bluepill that doesn't have 128k. Obviously if you were making a commercial product you would buy the stm32f103cb if you needed the 128k, but as a hobbyist obviously you don't care and just want bonus stuff for free. If it doesn't work, you just switch back to 64k. If it does work, Win!
Arduino active the internal pull-up resistor when Wire.begin(), is it the same for Bluepills?
I'm not an expert. Actually, I just learn the knowledge of pull-up resistor and frequency for Arduino lately.
Q6. Should all pins shared by Serial1/Wire1 be avoided? And does Serial1 conflict with Wire1(share PB6 PB7)?You want to use external resistors with a bluepill. On top have having high resistance internal pullups, the 3V3 voltage will round your I2C square waves to become useless. So you want to use a lower value than you would use on a 5V Arduino. So if you used to use a 2.2k on a 5v, you want to use ~1k5 on 3v3.
Cause Arduino did not recommend using 0 and 1 which is used by Serial Communication. The pinout gif of Bluepill shows that PA9 PA10 PB6 PB7 are all used by RX1 TX1, should I avoid using all of them when Serial1 is in use?
And PB6 and PB7 are also used by I2C Wire1. When Serial1 functioning, can Wire1 be used? And seems PB8 PB9 is shared with Wire1...will they be banned, too?
I'm quite confused about so many shared PINs for the communication functions.
Q7.I've found my Bluepill's LED_BUILTIN is reversed. And I search the forum and found this postIf you want to use the Serial1 pins as GPIO pins, fine do it. Same with Wire1.
This post explains the Bug of the LED_BUILTIN.
Does this Reversed LED Bug happen to any other pin of Bluepill?
A7. Couples of days passed, answer this myself. Yes, cause my STM32F103RE and STM32F407VE arrived and they both got a reversed onboard LED.
Answers mainly provided by Rick Kimball, thanks to him. And other kind members here.