KLST_SHEEP (v0.1) is a hand-held-sized development board with a TFT-Display, 2 push-button encoders, 16 LEDs and 2 serial ports, based on STM32H743VI MCU. it aims to facilitate the development of smaller audio applications. the board can be connected to other KLST_SHEEP boards via the serial IDC connector. it can be programmed via the Arduin IDE through the USB connector ( DFU mode ) or with an external programmer ( SWD mode ).

KLST_SHEEP--schematics

# FUNCTION DESCRIPTION
01 16 programmable LEDs LED_00 – LED_16 user programmable + dimmable LEDs
02 2× rotary encoders with push buttons
03 4× mounting holes M3 diameter
04 Display Connector mount for SPI connection to TFT display, usually fitted with a 2,8” TFT display with 240×320px resolution
05 3.3/5V power pins power in-+output pins. can either be used to power the board or to power peripherals if board is powered via USB
06 16× GPIO pins programmable GPIO pins, 3.3V tolerant only
07 JTAG/SWD interface 14-pin interface for external programmer ( e.g STLINK-V3 ) includes a dedicated serial debug line
08 programmer button sends board into DFU mode ( LEDs blink in pattern )
09 STM32H743VI MCU microcontroller ( MCU ) with 480MHz, 864KB RAM, 2048KB Flash
10 SD card reader Micro SD card reader, SPI-based
11 audio input, line-in 3.5mm, line level input for audio signals ( e.g vconnection to computer audio output )
12 audio output, line-out 3.5mm, line level output for audio signals ( e.g connection to HiFi systems )
13 headphones + mic 3.5mm, 3 ring audio jack with stereo output and mono input. can be used to connect e.g a headset.
14 IDC connector w/ power + UART SERIAL_01, can be used to connect e.g to other KLST_SHEEP boards, see 26
15 USB-A USB port for connecting USB Devices to board as USB host e.g computer mouse or keyboard
16 1× I2C I2C interface
17 1× SPI SPI interface, also used in Display Connector see 04
18 2× ADCs + 2× DACs additional ADCs + DACs w/ 12BIT resolution
19 audio in-+output + line-in+out same as 11 + 12
20 1× UART ( serial ) pin out for serial port, same ports as 07
21 1× SPI SPI interface
22 reset button resets board
23 boot flash button select boot mode. if button is held down during reset board starts in DFU mode
24 WM8731 Audio Codec audio DAC+ADC w/ 16BIT resolution and up to 48KHz sampling rate
25 power LED  
26 IDC connector w/ power + UART SERIAL_00 can be used to connect e.g to other KLST_SHEEP boards, see 14
27 USB-B micro + PWR USB port for connecting board as USB device. can also be used to program and power the board

Debugging

KLST_SHEEP features a dedicated serial port for debugging which is connected to the STLINK-V3 programmer. once connected to a computer the programmer creates a virtual serial port ( e.g on macOS it might look like this /dev/tty.usbmodemXXXXXXX ).

this port can be used e.g to exchange debug information with a USB Host e.g a computer running the Arduino application.

the example program below can be used to test the serial port:

#include "Klangstrom.h"

void setup() {
    Serial.begin(115200);
}

void loop() {
    Serial.println(".");
    delay(1000);
}

the 2 UART ( serial ) ports as well as the USB Device port can be used for other applications in parallel.

Feature List

  • STM32H743 MCU with 480MHz, 864KB RAM, 2048KB Flash
  • WM8731 audio codec with 2× audio DAC + 2× audio ADC ( 16/24BIT )
  • 1× LINE OUT ( stereo )
  • 1× LINE IN ( stereo )
  • 1× HEADPHONE + MIC ( mono )
  • 2× ADC ( 12BIT, opt 6 extra channels )
  • 2× DAC ( 12BIT )
  • 2× UART ( serial )
  • 16× GPIO
  • 1× USB Host
  • 1× USB Device ( + Power Supply )
  • 1× I2C
  • 1× SPI
  • 2× rotary encoders with push buttons
  • 16× programmable LEDs with PWM + 1× power LED
  • 1× SD card reader
  • 1× JTAG/SWD interface + serial debug ( 14-pin )
  • programmer + reset + boot flash buttons
  • 4× Mounting Holes

Errata

see Known Issues ( Application )