CANDis

Overview

Name	CANDis
URL	Link
SW-Project	Link
HW-Rev	v0.1.x
Docu	20220210
MCU	STM32G441KBT6
FLASH	128kB
RAM	16kB
HSE/LSE	8MHz/-
Display	DEM240320K-TMH / ILI9341V
Touch-controller	TI TSC2007; #253
NAND-Flash	GD25Q16CSIG; 16MBit; #233
RTC	MCP7940N; #254

CANDis is an small display-unit with touch display and CAN interface. USB is also available but not at the same time as CAN due to MCU limitations. The device can be flashed via USB.

PCB

Top	Bottom

Connectors

Debug

The board can be connected to an ST-Link of an Nucleo-64 board with the adapter “NUC64DEBUG”-Adapter. It fits to connectors CN3+CN4 of the Nucleo board. Use an 10 Pin, 0.5mm pitch, typ B FPC, both sides contacts on bottom (shipped with NUC64DEBUG). The connector on CANDis is hidden behind the lower middle plastic shaft which can be removed by removing the corresponding screw.

Connector-pin	MCU-Pin	Function
1	VDD	VDD Target
2	PA14	SWCLK
3	-	GND
4	PA13	SWDIO
5	NRST	NRST
6	-	NC (Reserved for SWO)
7	PA2	UART TX
8	PA3	UART RX
9	-	VIN 5V
10	-	BOOT0

CANBUS (JST 4 PIN)

Connector-pin	Function
1	GND
2	VDD
3	CAN-L
4	CAN-H

UI

Component	MCU-Pin	Function
LED D5 Green	PB7	Heartbeat
LED D2 Amber	PB8	LED User/Traffic
LED D1 Yellow (backside)	PB6	SELECT; ON:CAN; OFF:USB
LED D3 Green (backside)	VDD	LED Power
SW1, “B”	BOOT0	Boot Select
SW2, “R”	nReset	Reset

Errata

USB Bootloader

The STM32G441 has an internal USB bootloader. To enter it following procedure must be performed:

press and hold the BOOT button “B”
press and release the Reset button “R”
release the Reset button “B”

If the PC runs an Linux based operation system “lsusb” can be used to verify the presence of the STM32-Device

~$ lsusb
[...]
Bus 003 Device 029: ID 0483:df11 STMicroelectronics STM Device in DFU Mode
[...]

The application “STM32CubeProgrammer” can be used to flash the device. It is available on the homepage of ST.

Bringup software

The preinstalled bringup-software is intended to test basic functionality of the board. It shows an clock on the display, blinks LEDs and beeps when display is touched.

The MCUs RTC is synced with the external I2C-RTC only at startup. So a big drift can be observed while running. Resetting the board eliminstes the RTC drift.

An command line interface is available via USB.