PUGAUGE - Low Power Display Processor

The PUGAUGE is intended to be a base platform for devices to display Information in an environment where low power requirements are mandatory.

Examples are:

• Bike computers
• Thermometers
• mobile measurement devices

Hardware

• 8-Character Segmented LCD 14-segment Display
• Atmel AVR ATmega6490A AVR microcontroller

Software

Platform

The PUGAUGE is intended to be Arduino-compatible. The application software shall benefit from the ease of use, familiarity of many developers and availability of many libraries for sensors and other peripherals.

Therefore, an extension to the Arduino IDE is developed to allow the PUGAUGE being selected as a board type in the Arduino IDE. This should not be too complicated, as the PUGAUGE processor is an Atmel AVR processor closely related to the Atmel AVR processors used in the Arduino UNO and MEGA.

Additionally the optiboot bootloader for the Arduino is being modified to run on the PUGAUGE and allow Arduino sketches to be uploaded onto the PUGAUGE.(zu ergänzen)

Application

A special LCD library is being developed that provides easy access to the on board LCD ( 8 characters, 14 segments plus decimal point and apostroph).(zu ergänzen)

Build notes

Connection of ATmega6490

In the first development version all circuitry is mounted on a solderless breadboard:

• The ATmega6490 is mounted on the BBR.
• LCD-Voltage Buffer Capacitor: 3x220nF FKC in parallel from ATmega6490 Pin 1 / BBR Pin 76 to GND
• System Status LED: Port line PB0 (ATmega6490 Pin 19 / BBR Pin 94) to 330 Ohm to yellow LED to GND
• In-System-Programmer (IST) USPasp connected to 10-pin 2x5 100mil-spaced Connector:

See also http://nerdyelectronics.com/usbasp-tutorial/ :

                                                           Connector seen on board pins
USBasp pin number USBasp pin MCU Pin                          +---+---+---+---+---+
1 	          MOSI       MOSI                             | 2 | 4 | 6 | 8 |10 |
5                 Reset      Reset                            +---+---+---+---+---+
7                 SCK        SCK                              | 1 | 3 | 5 | 7 | 9 |
9                 MISO       MISO                             +---+---+---+---+---+
10                GND        GND
2                 Vcc        Vcc

Signal name	description	10-pin-conn pin number	ATmega6490 pin name	ATmega6490 pin number	BBR pin number
MOSI	data from programmer to MCU	1	MOSI	21	96
Reset	reset pulse to MCU	5	Reset	30	5
SCK	serial clock to MCU	7	SCK	20	95
MISO	data from MCU to programmer	9	MISO	22	97
GND	Ground reference	10	GND	99,11,32,81	74,86,7,56
VCC	+5V supply from programmer	2	VCC	100,10,31,80	75,85,6,55

• Serial-USB Adapter, connected to TXD/RXD of UART0 of ATmega6490:

Signal name	description	FT323-adapter pin	ATmega6490 pin name	ATmega6490 pin number	BBR pin number
GND	Ground reference	GND	GND
TXD	data from USB to MCU	TXD	RXD/PCINT0/PE0	2	77
RXD	data from MCU to USB	RXD	TXD/PCINT1/PE1	3	78

TQFP-100 Breakout board

When soldering the AVR6490 Chip in the TQFP-100 case to it's breakout board, I made an error:

I turned it 90 degrees to the right. Therefore Pin 1 of the chip appears at Pin 76 of the breakout board.

The algorithm to find the BBR pin when knowing the pin number on the TQFP-100 package of the ATmega6490 is:

BBR-pin = (TQFP-pin + 75) MOD 100

There will be a translation table on the PUGAUGE tables page.

Connection from the D301 LCD to the PUGAUGE MCU is documented on the PUGAUGE Tables page.

Font made visible

Likewise, a graphic depiction of the 14-Segment font is to be found on the PUGAUGE Tables page.