Search found 1643 matches

by victor_pv
Tue Oct 17, 2017 4:52 pm
Forum: Custom design boards
Topic: Alternative BluePill sized F4
Replies: 14
Views: 169

Re: Alternative BluePill sized F4

Racemaniac, this article from Linear can provide some information on using several LDOs to share the load: http://www.linear.com/solutions/5759 About voltage regulators, I just noticed this one in Mouser, listed as new: LDL1117S33R Only 250uA quiescent current, and 350mV dropout Still the AP2114 Squ...
by victor_pv
Sun Oct 15, 2017 12:31 am
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 161
Views: 1924

Re: F405 & F411 versions of the BluePill

From the 405/407 reference manual, section 34.3.2: Pull-up/pull-down resistor ECN circuit. The DP pull-up consists of 2 resistors controlled separately from the OTG_FS as per the resistor Engineering Change Notice applied to USB Rev2.0. The dynamic trimming of the DP pull-up strength allows for bett...
by victor_pv
Sat Oct 14, 2017 7:03 pm
Forum: Code snipplets
Topic: Unique device ID (and flash size)
Replies: 18
Views: 4443

Re: Unique device ID (and flash size)

In fact if the MCU is "STM32F103CB" as you wrote, that should have 128KB according to the specs. The STM32F103C8 (note is a number 8 not upper case b) is supposed to have only 64KB. So if you have a CB with 128KB, you are exactly within specs. If you have a C8 with 128Kb, then as Dannyf pointed is c...
by victor_pv
Sat Oct 14, 2017 6:57 pm
Forum: New users MUST post here first, and let us know a bit about you and your projects
Topic: minimal Custom board for STM32F103C8T6
Replies: 4
Views: 118

Re: minimal Custom board for STM32F103C8T6

any idea we should keep or remove below components from the MCU section? 1)C3,C4,C10,C11 <- any idea use for what purpose?? 2)Y3,C9,C12 <- any idea use for what purpose?? 3)C13,C14,Y2,R6 <- i think this one is the main crystal right? 1) Those are needed, decoupling and filtering capacitors, one of ...
by victor_pv
Sat Oct 14, 2017 4:43 am
Forum: USB bootloader
Topic: What Baudrate using stm32 arduino bootloader
Replies: 1
Views: 67

Re: What Baudrate using stm32 arduino bootloader

The baud rate is irrelevant when using the USB peripheral. The transfer is managed thru a handshake process involving acknowlegments, when an acklodgement is not received from the other end, the transfer pauses. So the host will send data as fast as the maple mini can read it from the usb peripheral...
by victor_pv
Sat Oct 14, 2017 4:33 am
Forum: New users MUST post here first, and let us know a bit about you and your projects
Topic: minimal Custom board for STM32F103C8T6
Replies: 4
Views: 118

Re: minimal Custom board for STM32F103C8T6

The chrystal is only really necesary for USB, because the internal RC oscillator is not precise enough across the full temperature range. But some people has even tested and used USB without and external crystal, it's just not guaranteed to work. If you don't use USB, you should be totally find with...
by victor_pv
Thu Oct 12, 2017 8:31 pm
Forum: New users MUST post here first, and let us know a bit about you and your projects
Topic: Greetings From Dallas
Replies: 5
Views: 140

Re: Greetings From Dallas

Didn't know there were so many members in Austin :)
by victor_pv
Wed Oct 11, 2017 1:42 pm
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 161
Views: 1924

Re: F405 & F411 versions of the BluePill

The price is also quite high (around $15), especially since that a TaoBao price not an inflated AliExpress or eBay price Right, the price doesn't compare, that's why I didn't save it the first time I saw that board, had to look for the link again. Hopefully between racemaniac and lkcl something can...
by victor_pv
Tue Oct 10, 2017 5:48 am
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 161
Views: 1924

Re: F405 & F411 versions of the BluePill

I had been looking for this link since I saw this conversation started, but just found it again. It's an F405 board similar to a bluepill (although likely larger, I haven't compared). Just for reference: https://world.taobao.com/item/553628950823.htm?fromSite=main&spm=a230r.1.14.12.76bf523j7Ovvn&ns=...
by victor_pv
Sun Oct 08, 2017 11:43 pm
Forum: Code snipplets
Topic: Unique device ID (and flash size)
Replies: 18
Views: 4443

Re: Unique device ID (and flash size)

If I remember right there is some write once bytes, so you can program your own ID.
Can't remember it for certain though.