Search found 1697 matches

by Pito
Wed Jan 17, 2018 10:03 pm
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 626
Views: 11859

Re: F405 & F411 versions of the BluePill

Yea, that fmax is for a straight wire of length l, I think. Such big loop of wires is like a planar transformer :)..
Anyhow, I have to stop with seeing the :twisted: in the details ..
by Pito
Wed Jan 17, 2018 5:23 pm
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 626
Views: 11859

Re: F405 & F411 versions of the BluePill

or anyone sees an advantage on having the panel? They do not provide Vcut within a panel when the individual board is less than 80x80mm.. (do select "Panel Separating Way:") So the only option is, for example, to buy Single PCB, 60pcs 64x16mm, $19 as of today. PS: It seems they are steadily increas...
by Pito
Wed Jan 17, 2018 2:39 pm
Forum: Libraries & Hardware
Topic: Stm32f103C8 External Dac
Replies: 21
Views: 342

Re: Stm32f103C8 External Dac

You may write an R2R DAC sample in 4 clocks (~56ns) with any pins on PortA and PortB (ie. up to 32bit R2R) - see my previous post.. :)
It requires to write a sketch for generating the DAC sample's "source code" sequence (writing the sketch is left as an exercise to the OP)..
by Pito
Wed Jan 17, 2018 2:19 pm
Forum: Libraries & Hardware
Topic: Stm32f103C8 External Dac
Replies: 21
Views: 342

Re: Stm32f103C8 External Dac

The fastest way would be to generate a set of DAC "commands" like .. sample_delay(); // *********************** Output the Sample N. 345 ************************ //Set A2, A12, A13 (HIGH) GPIOA->regs->BSRR = 0b0011000000000100; //Clear A3, A11, A15 (LOW) GPIOA->regs->BRR = 0b1000100000001000; //Set ...
by Pito
Wed Jan 17, 2018 7:56 am
Forum: Projects
Topic: Time interval counter (13ns resolution)
Replies: 4
Views: 146

Re: Time interval counter (13ns resolution)

The GPSes 1Hz tick is not precise short term, but long term. Based on module and conditions short term jitter could be XXns- Xuseconds. Thus the tick itself cannot be used as the base for a counter for example. You have to discipline a quality OCXO with the 1Hz tick to get precise output. The sawtoo...
by Pito
Tue Jan 16, 2018 10:47 pm
Forum: Libraries & Hardware
Topic: Stm32f103C8 External Dac
Replies: 21
Views: 342

Re: Stm32f103C8 External Dac

Try to order the changing the DACvalue bits from the highest bit to the lowest (as I did in my code above). Like in your code: for (byte i=7; i >=0; i--) { byte state = bitRead(num, i); digitalWrite(DPINS[i], state); } I would recommend to you to use my code above as it is much faster. Also you may ...
by Pito
Mon Jan 15, 2018 6:00 pm
Forum: Libraries & Hardware
Topic: Stm32f103C8 External Dac
Replies: 21
Views: 342

Re: Stm32f103C8 External Dac

He may apply an algorithm, where the bits between the DAC samples change such the turmoil at the output will be minimal :)
by Pito
Mon Jan 15, 2018 2:48 pm
Forum: Libraries & Hardware
Topic: Stm32f103C8 External Dac
Replies: 21
Views: 342

Re: Stm32f103C8 External Dac

You may set the bits individually. First set the individual pins to outputs, then write the DACvalue: pinMode(PA0, OUTPUT); .. pinMode(PB12, OUTPUT); .. // write the DACvalue 0-255, 8bit digitalWrite(PA4, (DACvalue & 0x80)); // the highest DACvalue bit7 digitalWrite(PA3, (DACvalue & 0x40)); digitalW...
by Pito
Mon Jan 15, 2018 2:44 pm
Forum: STM32generic
Topic: SPI.transfer of byte crashes F407VET6?
Replies: 10
Views: 135

Re: SPI.transfer of byte crashes F407VET6?

SPI transactions are the most simple you may imagine. It just clocks out 8 bits and reads 8 bits in. That is all. The only issues I can imagine with using SPI with two or more different chips hanging on it: 1. wrong chip selects manipulation (you activate both chips during a transaction) 2. the chip...