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: 1808
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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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
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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 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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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: 77
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?

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

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

Post by electrobling » Sun Mar 25, 2018 12:56 am

I got 2 boards. I have to say, I'm impressed. Some things I like: UART1 comes out on a connector so you can install a bootloader without any soldering. There is an EEPROM chip factory installed (although I'm using the flash EEPROM emulation library at the moment). The compatible connections make it possible to add a cheap 64x128 OLED and ESP-01 and NRFL01 without any hardware mods or kludgy wiring. They provisioned the 32kHz oscillator and didn't burden the crystal with external I/O connections. There are mounting holes, yay! Here is a shot of a clock project running:
CIN_1296.jpg
CIN_1296.jpg (209.07 KiB) Viewed 606 times
I assembled the above one "backwards" to mount the OLED almost flush with the board. I populated the 32Mb flash IC position but haven't played with it yet. I ordered an additional 4 boards, these could become my "go to" board. Assembled the normal way:
CIN_1293.jpg
CIN_1293.jpg (206.19 KiB) Viewed 606 times
Last edited by electrobling on Sun Mar 25, 2018 1:19 am, edited 2 times in total.

electrobling
Posts: 77
Joined: Fri Jan 26, 2018 9:28 pm

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

Post by electrobling » Sun Mar 25, 2018 1:13 am

Here are some board shots:
CIN_1279 (1) .jpg
CIN_1279 (1) .jpg (230.94 KiB) Viewed 603 times
CIN_1280 (1) .jpg
CIN_1280 (1) .jpg (204.21 KiB) Viewed 603 times

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zoomx
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Location: Mt.Etna, Italy

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

Post by zoomx » Sun Mar 25, 2018 6:28 pm

I have populated the microSD slot.

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

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

Post by electrobling » Sun Mar 25, 2018 10:54 pm

zoomx wrote:
Sun Mar 25, 2018 6:28 pm
I have populated the microSD slot.
Great. I have 10 holders on order. I placed D3 so that VBAT is powered from VCC, even if there is no battery. That should improve LSE stability. If you use the LSE, and plan to never place a battery, the pads could be shorted to do that. I will pull a pin from the ESP socket and jumper CH_PD to PB14 so I can shut down the ESP-01 when it is not in use.

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