ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Generic boards that are not Maple or Maple mini clones, and don't contain the additional USB reset hardware
zmemw16
Posts: 1685
Joined: Wed Jul 08, 2015 2:09 pm
Location: St Annes, Lancs,UK

Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by zmemw16 » Sun Jan 28, 2018 6:26 pm

unfortunately i discovered with a cz_ministm32f103 that the 2.1mm external psu connection is a good fit to a 12v wall wart, missed the silk screen indicating it's for a 5v one wry :)
not a good result

a very long time ago, i used a transformer 6v ac winding, full diode bridge and a 6v dc capacitor for smoothing.
i also discovered i could navigate 3 floors of stairs to the water tap with my eyes shut.
then again i've never repeated it either.

when looking at the schematics, we need to work out how the designer sees the peripheral devices.
it maybe that they don't see them as straight out interfaces, but in order to get the required devices to meet their specifications they've used that ability to remap ( move ) them to different pins.
so we read the schematic and because of remapping means they've moved spi1 to the spi3 pins and i2c1, spi2, i2c2 ... ... etc as an example they might need both 3v3 & 5v tolerant spi interfaces, moving spi1 (portA 3.3v) to spi3 (portB 5v)
also they might as all the outside world (us) uses them rename(renumber) the interfaces spi1->sp3 spi2->spi1 etc
stephen

flodejr
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Joined: Sat Sep 16, 2017 2:46 pm

Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by flodejr » Fri Feb 02, 2018 4:44 pm

The USB on my board doesn't seem to want to work. Checked the resistor values and they are correct, 20R to PA11 and PA12 and 1.5K pull-up to 3.3V. What could be wrong? I just received this board recently.

stevestrong
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Location: Munich, Germany
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Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by stevestrong » Fri Feb 02, 2018 5:13 pm

If you got blue pills, then do not wonder, 2 out of 10 cheap boards are statistically "bad", showing not working USB, or not starting crystal.

flodejr
Posts: 37
Joined: Sat Sep 16, 2017 2:46 pm

Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by flodejr » Fri Feb 02, 2018 5:31 pm

stevestrong wrote:
Fri Feb 02, 2018 5:13 pm
If you got blue pills, then do not wonder, 2 out of 10 cheap boards are statistically "bad", showing not working USB, or not starting crystal.
After some inspection, it seems that pin 1 and pin 2 on the micro-usb connector seems to be shorted. Looks like I have to reflow that connector and see if it works properly after that.

stevestrong
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Location: Munich, Germany
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Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by stevestrong » Fri Feb 02, 2018 5:53 pm

First two pins are both tied to GND, that is normal.

electrobling
Posts: 24
Joined: Fri Jan 26, 2018 9:28 pm

Re: ebay 103c8t6 oled, nrf24, esp8266 + empty pads

Post by electrobling » Mon Feb 05, 2018 11:21 am

Are you sure the bootloader is installed correctly?

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