IB8000/IB3710 STM32 Overview

Revision and Notes

Date

Owner

Revision

Notes

Date

Owner

Revision

Notes

Apr 18, 2022

 

1.0

Initial release

Table of Contents

 

STM32 / MCU

Hardware

Overview

The STM32 family of 32‑bit Flash microcontrollers based on the ARM® Cortex®‑M processor is

designed to offer new degrees of freedom to MCU users. It offers a 32‑bit product range that combines very high performance, real-time capabilities, digital signal processing, and low‑power, low‑voltage operation while maintaining full integration and ease of development.

The SR IB-E8000 and IB-N3710 got the STM32F042K4U6 on the MicroSom.

Documents

Link

Documents

Link

STM32 reference manual

Download

STM32 datasheet

Download

The STM32F042x microcontrollers incorporate the high-performance ARM Cortex-M0 32-bit RISC core operating at a 48 MHz frequency, high-speed embedded memories (up to 32 Kbytes of Flash memory and 6 Kbytes of SRAM), and an extensive range of enhanced peripherals and I/Os. All devices offer standard communication interfaces (one I2C, two SPIs/one I2S, one HDMI CEC and two USARTs), one USB Full speed device (crystal-less), one CAN, one 12-bit ADC, four general-purpose 16-bit timers, a 32-bit timer and an advanced-control PWM timer.
(source: datasheet)

STM32 supports HDMI CEC and other features.

STM32 Schematics on the MicroSom

  • MCU_BOOT0 – selects boot from USB or normal – GPIO 349

  • MCU_RESET – resest the MCU – GPIO 351

  • Both signals are natively pulled up high from the processor

Code-Example for controlling the GPIOs via Linux

cd /sys/class/gpio echo 349 > export cd gpio349 echo 0 > value echo 1 > direction cat gpio349

MCU Wakeup circuit

The MCU got the ability to wake up the CPU from sleep mode.
Notice that this is an example implementation on the SolidPC carrier.

Level shifts through resistors from 3.3v to 1.8v

Testpoints

Notice that this is an example implementation on the SolidPC carrier.
MCU: STM32: PA1..PA4 pins

Testpoint TP19,TP20 and TP18 is located next to UART1 (covered when the Som is assembled)
TP21 (left one) can be found on the opposite side of the PCB.
Additional Testpoint-information: SolidPC Testpoints

Software

Thanks to our community developer GDA who created a working firmware for the stm32.

The firmware, libcec port, RainshadowAdapter-work is not maintained by Solid-Run.

Firmware STM32

The latest .bin file can be found here:

https://github.com/gdachs/cecbridge/raw/rainshadow/Debug/CECbridge.bin

LibreElec (Kodi)

All work concerning LibreElec can be found here:

https://github.com/vpeter4/LibreELEC.tv/commits/solidpc

The easiest way to get CEC running under Kodi is to use the latest SolidPC LibreElec image here:

flash it to your storage and run

The flash process will take some time.

After a reboot cec functionality should work.

Rainshadow/RainConf

RainConf communicates directly with the STM32. (All processes need to be stopped which use LibCEC)

How to build rainconf:

Hint: RainConf needs P8-Platform library
Which can be found here: https://launchpad.net/~yavdr/+archive/ubuntu/main

LibCEC

SolidRun Ltd.