STM32?

[gohan]

Well I probably confused with another Arduino board 😌

[VaZso]

@alowhum I use the same board as dev board and it works well, I had no problems with it using STM32's own libraries.
It has I2C, SPI, UART, even USB and 5V-tolerant inputs and so on.
I like it. :)

[gohan]

but for a battery powered sleeping node it is better a mini pro that hasn't the usb chip that drains power, right?

[scalz]

@gohan
This ST32 board doesn't have any usb chip, and doesn't need one, because the mcu already includes this feature.

[alowhum]

This board just keeps getting better and better.

Is there a way to try out this new functionality? I coincidentally could really use a 3.3 volt Arduino with micro-USB port.

I don't like that the Pro Mini doesn't have a micro usb port for powering it. The Digispark Pro does have it, but I don't know if MySensors supports it. More importantly, it's twice as expensive.

[mfalkvidd]

@alowhum a bit off topic, but I've bought a few micro usb connectors to be able to use the ubiquitous phone chargers to power Pro Minis.

To try out the new functionality, order a few STM32. Then use the master MySensors branch from github. https://github.com/mysensors/MySensors/pull/795 will probably have been merged by the time your boards arrive :) If they haven't you can use tekka's branch.

[scalz]

Also, little sidenote, it's low power mcu i think, maybe not pico like 328p. And i don't know about the mysensors sleep functions (not implemented yet i think).
But that said, it's a nice competitive alternative, like others ARM mcus which are very versatile :yum: (a bit more advanced than simple 8bit 328p) .

Big thx to @tekka for his work on this nice addition, you rock :+1:

Digispark pro may run mysensors, for very simple, no big memory task as it's using a smaller mcu than 328p for instance (i don't remember if attiny85 implementation has already been released).

[alowhum]

Cool! I'll try that with the one I have already. In my sketches I try to make a non-sleep option, so the lack of sleep should not be a problem. Heh, funny sentence.

Will I also need to install the STM32 library?

[scalz]

@alowhum
this is starting to be a problem for me..the lack of sleep :smile:

yes, i think you need to follow the howto you linked (for installing the core files)

[VaZso]

@gohan Regarding of battery powered system...

From STM32CubeMX power consumption calculator, it has the following current requirements:

In RUN mode:

• at 72MHz bus frequency, it needs 27 mA
• at 16MHz and HSI PLL, it needs 6.8 mA
• at 8 MHz and HSI, it needs 4 mA
• at 1 MHz and HSI, it needs 900 μA
• at 125 kHz and HSI, it needs 480 μA

---

In STANDBY mode with all clocks off, it needs 2 μA

---

In SLEEP mode:

• at 125 kHz bus frequency and HSI, it needs 410 μA
• at 1 MHz bus freq. and HSI, it needs 440 uA
• at 8 MHz, it needs 600 μA

---

Enabling the following peripherals, additional consumptions are (as for example):

• GPIOA needs 833.75 nA
• GPIOD needs 816.25 nA
• I2C needs 1.25 μA
• SPI1 needs 590 nA
• TIMER1 needs 2.92 μA
• TIMER2 needs 4.06 μA
• TIMER4 needs 3.99 μA
• USART1 needs 1.49 μA
• USART3 needs 1.53 μA
• USB needs 2.22 μA
• Window watchdog needs 312.5 nA
• Independent watchdog needs 1.71 μA
• ADC1 needs 162.19 μA

These are just some examples, not all possibilities and frequencies are listed here...

There are also lower power STM32 series anyway.

[gohan]

I'm curious because I saw these boards few months ago but I figured that community support was still in the early stages so I kind of didn't pay much attention to them and I preferred old but tested technology 😁

[alowhum]

The patch has just been added to the Mysensors Development branch, so it's easier to try out.

I've created a guide on how to get started on the SMT32Duino forum.

[alowhum]

Heh, the STM32 doesn't have a digital pin 2 it seems. Where is the NRF supposed to connect to instead?

[mfalkvidd]

@alowhum looks like PA3: https://github.com/mysensors/MySensors/pull/795/commits/ac432acca3d7c58eb7c8f569dc562860605ea09f#diff-58c572256858a37808c4ebd0922b4060R50

[alowhum]

That's odd. I thought I had it just figured out. I'm about to test this at the top of a sketch:

#define MY_RF24_CE_PIN PB0
#define MY_RF24_CS_PIN PA4
#define MY_RF24_MOSI_PIN PA7
#define MY_RF24_MISO_PIN PA6
#define MY_RF24_SCK_PIN PA5
#define MY_RF24_IRQ_PIN PB10

The fun thing is all the pins are almost in a row. Almost. And if the IRQ is A3, then one more pin would line up..

According to this image the IRQ is pin PB10 though:
http://wiki.stm32duino.com/images/a/ae/Bluepillpinout.gif

[mfalkvidd]

@alowhum sorry I misread your question. Don't know why, but I didn't see that you were talking about the NRF.

IRQ is not used for the NRF on Arduino, so I supposed it is not used for STM32 either. There is nothing about IRQ in https://github.com/mysensors/MySensors/pull/795/commits/ac432acca3d7c58eb7c8f569dc562860605ea09f#diff-cf14b6301beb3a4dbaded9b95bb190feR487

[alowhum]

Really? On the Arduino nano I'm always connecting it to pin 2. It says to do so in the guide?

Anyway, I haven't been able to get it to work. Perhaps some of the developers van shed some light on how it's supposed to work?

[tbowmo]

@alowhum

Its first in recent (develop branch?) that interrupt usage with nRF24L01 have been enabled, and only in certain scenarios.

[tekka]

@alowhum The MySensors RF24 driver is a polling driver (unless RX queuing is enabled), hence no IRQ required.

I've successfully tested the RF24 radio with this wiring on a BluePill board using MySensors 2.2.0-beta:

CLK -> PA5
MISO -> PA6
MOSI ->PA7
CSN -> PA4
CE -> PB0

do not forget to set:

#define MY_RF24_CE_PIN PB0

[alowhum]

Hmm, that's pretty much what I had.

Could you perhaps share your example sketch?

// It's working now! Turns out I had to set the radio to low power..