Arduino Primo has STM32F103R8 – but only uses it for USB !

…at the first look it looks to me like STM32F103xxx are so cheap, that they are used for 2nd or 3rd level “support jobs” like USART to USB converter.
on a second view the list is longer:

• USB/Uart converter
  CMSIS-DAP
  GPIO expander
  Board power management
  IrDA

but the whole primo design looks a little bit strange to me, like a ESP32 “wanna be” or a (sorry for the german phrase, and there is definitely no translation for this word) “Eierlegendewollmilchsau”
…and why they didn’t implement an additional 433mhz module the get the whole RF spectrum?

…but wait:
Laut Aussage auf der maker faire Hannover wird er ca. 30 € kosten
Ok, for 30 bucks this could be a real nice toy to play

Seems a bizarre mash-up

Its not open source hardware but there is a leaked block dia

I suspect they use the ESP8266 for the GPIO and everthing else is a slave, and the STM32 is just for USB etc, (perhaps so they can separately flash the ESP8266 and the nRF52

The nRF52 is a Cortex M3 device and almost as fast as the STM32 and could easily be used as the main device as well.

Edit.

Actually, if the block diagram is correct, It looks like the nRF52 is the main processor.

The STM32 is being used for SWD programming of the nRF52, I wonder if they are using the BlackMagic Probe code for that.

The ESP8266 seems to just connect via UART, so they probably use the AT command set

Not really related to the STM32 but as the nRF52 is the main processor, I presume Arduino.cc will be writing a Arduino core for this.

I know that Sandeep Mistry was writing a nRF52 core, and I think he now works for Arduino, but I was under the impression that his core was not an official one.

I’ll post an issue to clarify this

RogerClark wrote: I presume Arduino.cc will be writing a Arduino core for this.

@zoomx

Sorry. I should have updated my post.

I realized its Arduino.org, so I have sent an email to Francesco to find out who is developing the Core for the nRF52

To be very evil:
On this board we have 3 MCU’s with “Arduino IDE” support.
But why they choose the (nearly) “weakest” one as “main processor”? (ok, Cortex-M4, but very less pins for the user: Analog I/O Pins
6 + 1 DAC )
I assume that Nordic will settle down in “Arduino Land”

So please don’t understand me right, the NORDIC nRF52832 looks like a really cool MCU, but with this combination? That’s totally odd for me.

off-topic thinking: …and why is the new OTTO-STAR board with a STM32F4xxx and not with STM32F7xxx? This could be a really game changer.

I will be interesting to see how much the board will cost.

As although the nRF52xxx is a great MCU its quite expensive. I took a look on Aliexpress and the cheapest nRF52 board I can find is $22.
And the same company make an nRF51 board for approx $5.

So in terms of the whole package of the Primo, virtually the same functionality could be produced by using a GD32F103RET, nRF51 and the ESP8266.

Or perhaps an STM32F4 as the main processor.

Of course this would not have RFID but I think perhaps a modular approach would be better for the whole design, as I am not sure who really needs all those radio interfaces.

For RFID you better use your (middle class) smartphone or use those cheapo RC522 kits.
…and as I wrote: The ESP32 will be released soon and I guess this would be the hardest competitor for the Primo.
And with all those junk you never be a able to produce a low power device out of it, so the nRF52xxx is reduced to absurdity.

I presume the board must be aimed at the education market where they don’t need to worry about real world problems like power usage.

I found that the Texas Instruments boards take care of power consumption despite they are educational too.
You can disable onboard LEDs using jumpers.
Furthermore programming part of the board (and power) can be separated by jumpers too so you can play with low power.