bfh_electronics.md

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Electronics

Introduction

Based on EKI-LM3S6965 dev board (ARM Cortex-M3), now owned by TI: link

datasheet

Not recommended for new designs!!!

> This MCU is obsoleted and not recommended for new designs.
>
> This board was chosen because I had one sleeping on my desk.
> HW and FW are done so that they could easily be ported to another
> TI-based MCU/dev board, or any ARM Cortex-MCU.

Key Features

• 50MHz clock
• 256KB embedded flash
• 64KB embedded RAM
• 10/100 Ethernet port (MAC + PHY)

Block Diagrams

Pinout

The dev board has two breakout connectors. Some of the pins have a dedicated usage on the dev board. Some of the dev board features (and thus pins) are used, like the OLED display, buzzer, navigation buttons, etc.

If an alternate use of the pin is required, a soldering bridge can be cut to free the pin from its dedicated usage.

The following tables show the allocated usage for each breakout connectors.

Comment	EK Usage	Description	Pad No	Pad No	Description	EK Usage	Comment
Cat feed pad out.		PD4/CCP0	34	33	PB4/C0-		BLE CSn
		PD6/FAULT	32	31	PD5/CCP2
		GND	30	29	PD7/CCP1
		ADC1	28	27	ADC0
		ADC3	26	25	ADC2
SmartCard SPI CSn signal.	CARDCSn	PD0/IDX0*	24	23	GND
		PD2/U1RX	22	21	PD1/PWM1*	SOUND	Speaker.
		PG1/U2TX	20	19	PD3/U1TX
Data/Control#	OLEDDC	PC7/PHBO*	18	17	PG0/U2RX
		PC5/C1+	16	15	PC6/CCP3*	EN+15V	OLED +15V enable.
		GND	14	13	PC4/PHA0		Manual feed pad out.
		+3.3V	12	11	PA0/U0RX*	VCP_RX	USB Stuff. Don't touch.
USB Stuff. Don't touch.	VCP_TX	PA1/U0TX*	10	9	PA2/SSI0CLK*	SSICLK	SPI Clock signal.
RTI OLED display SPI CSn signal.	OLEDCSn	PA3/SS0FS*	8	7	PA4/SSI0RX*	SSIRX	SPI Rx signal.
SPI Tx signal.	SSITX	PA5/SSI0TX*	6	5	PA6/SCL1		RTCC SQW.
RTCC CSn		PA7/SDA1	4	3	GND
		GND	2	1	+5V

---

Comment	EK Usage	Description	Pad No	Pad No	Description	EK Usage	Comment
		+12V	35	36	GND
Motor controller BIN2.		PB5/C1-	37	38	PB6/C0+		Motor controller BIN1.
	JTAG	PB7/TRSTn	39	40	PC2/TDI*	JTAG
	JTAG	PC3/TDO*	41	42	PE3/PHA1*	RIGHT_SWn	Right Button.
Left button.	LEFT_SWn	PE2/PHB1*	43	44	GND
Up button.	UP_SWn	PE0/PWM4*	45	46	PE1/PWM5*	DOWN_SWn	Down Button.
Reserved for I2C.		PB2/SCL0	47	48	PB3/SDA0		Reserved for I2C.
BLE IRQn		PB1/PWM3	49	50	GND
Select button.	SELECT_SWn	PF1/IDX1*	51	52	PB0/PWM2		Motor controller PWMA input.
RJ45 Link/Activity LED.	LED0	PF3/LED0*	53	54	PF2/LED1*	LED1	RJ45 Link/Activity LED.
		GND	55	56	OSC32
		GND	57	58	OSC32
Status LED.	LED2	PF0/PWM0*	59	60	+3.3V

> In tables above, an asterisk (*) by a signal name (also on the EVB PCB) indicates the signal
> is normally used for on-board functions.
>
> Normally, you should cut the associated jumper (JP1-15) before using an assigned signal
> for external interfacing.

Adapter Board

An adapter board has to be build for interfacing the MCU dev board with all the various 3rd-party extension/breakout boards.

Adapter board construction

3rd-Party Extension/Breakout Boards

Touch sensors

Manual Feed Pad is done with a toggle capacitive touch sensor from AdaFruit. It is based on AT42QT1012.

Cat Feed Pad is done with a momentary capacitive touch sensor from AdaFruit. It is based on AT42QT1010. It is installed away from the main board, linked to it via a connector.

PWM motor controller

The DC/Stepper motor controller breakout board is the one from AdaFruit. It can control two motors. It is build around TB6612 motor driver. Only motor controller half 'A' is used.

RTCC

The RTCC breakout board is from SparkFun. It is build on the DS3234.

It was selected because of its accuracy (temperature compensated), alarm capabilities and its battery-backup'ed RAM. It is used by FW to store settings

RFID Detector

The RFID controller from AdaFruit is installed remotely of the board using a connector.

Bluetooth Low Energy (BLE)

The BLE board is from Adafruit. This version uses an SPI interface to communicate with the MCU.