PUGAUGE - Low Power Display Processor

Hardware

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

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		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

This table provides a correction lookup:

Pin of TQFP-100 ATmega6490A	Pin of breakout board	Pin of TQFP-100 ATmega6490A	Pin of breakout board
1	76	51	26
2	77	52	27
3	78	53	28
4	79	54	29
5	80	55	30
6	81	56	31
7	82	57	32
8	83	58	33
9	84	59	34
10	85	60	35
11	86	61	36
12	87	62	37
13	88	63	38
14	89	64	39
15	90	65	40
16	91	66	41
17	92	67	42
18	93	68	43
19	94	69	44
20	95	70	45
21	96	71	46
22	97	72	47
23	98	73	48
24	99	74	49
25	100	75	50
26	1	76	51
27	2	77	52
28	3	78	53
29	4	79	54
30	5	80	55
31	6	81	56
32	7	82	57
33	8	83	58
34	9	84	59
35	10	85	60
36	11	86	61
37	12	87	62
38	13	88	63
39	14	89	64
40	15	90	65
41	16	91	66
42	17	92	67
43	18	93	68
44	19	94	69
45	20	95	70
46	21	96	71
47	22	97	72
48	23	98	73
49	24	99	74
50	25	100	75

Connecting D301 LCD to ATmega6490 MCU

LCD pin name	pin functions	MCU pin name	MCU pin number	BBR pin number
pin_1	function/plane digit segment com1 1 seg_x com2 1 seg_f com3 1 seg_e com4 1 seg_d	SEG2	72	47
pin_2	function/plane digit segment com1 1 seg_i com2 1 seg_j com3 1 seg_k com4 1 seg_n	SEG3	71	46
pin_3	function/plane digit segment com1 2 seg_s com2 2 seg_f com3 2 seg_e com4 2 seg_d	SEG6	68	43
pin_4	function/plane digit segment com1 2 seg_i com2 2 seg_j com3 2 seg_k com4 2 seg_n	SEG7	66	41
pin_5	function/plane digit segment com1 3 seg_s com2 3 seg_f com3 3 seg_e com4 3 seg_d	SEG10	63	38
pin_6	function/plane digit segment com1 3 seg_i com2 3 seg_j com3 3 seg_k com4 3 seg_n	SEG11	58	33
pin_7	function/plane digit segment com1 4 seg_s com2 4 seg_f com3 4 seg_e com4 4 seg_d	SEG14	55	30
pin_8	function/plane digit segment com1 4 seg_i com2 4 seg_j com3 4 seg_k com4 4 seg_n	SEG15	54	29
pin_9	function/plane digit segment com1 5 seg_s com2 5 seg_f com3 5 seg_e com4 5 seg_d	SEG18	51	26
pin_10	function/plane digit segment com1 5 seg_i com2 5 seg_j com3 5 seg_k com4 5 seg_n	SEG19	50	25
pin_11	function/plane digit segment com1 6 seg_s com2 6 seg_f com3 6 seg_e com4 6 seg_d	SEG22	47	22
pin_12	function/plane digit segment com1 6 seg_i com2 6 seg_j com3 6 seg_k com4 6 seg_n	SEG23	46	21
pin_13	function/plane digit segment com1 7 seg_s com2 7 seg_f com3 7 seg_e com4 7 seg_d	SEG26	43	18
pin_14	function/plane digit segment com1 7 seg_i com2 7 seg_j com3 7 seg_k com4 7 seg_n	SEG27	41	16
pin_15	function/plane digit segment com1 8 seg_s com2 8 seg_f com3 8 seg_e com4 8 seg_d	SEG30	38	13
pin_16	function/plane digit segment com1 8 seg_i com2 8 seg_j com3 8 seg_k com4 8 seg_n	SEG31	37	12
pin_17	function/plane digit segment	COM3	75	50
pin_18	function/plane digit segment	COM2	76	51
pin_19	function/plane digit segment	COM1	77	52
pin_20	function/plane digit segment	COM0	78	53
pin_21	function/plane digit segment com1 8 seg_a com2 8 seg_b com3 8 seg_c com4 8 seg_p	SEG28	40	15
pin_22	function/plane digit segment com1 8 seg_h com2 8 seg_g com3 8 seg_l com4 8 seg_m	SEG29	39	14
pin_23	function/plane digit segment com1 7 seg_a com2 7 seg_b com3 7 seg_c com4 7 seg_p	SEG24	45	20
pin_24	function/plane digit segment com1 7 seg_h com2 7 seg_g com3 7 seg_l com4 7 seg_m	SEG25	44	19
pin_25	function/plane digit segment com1 6 seg_a com2 6 seg_b com3 6 seg_c com4 6 seg_p	SEG20	49	24
pin_26	function/plane digit segment com1 6 seg_h com2 6 seg_g com3 6 seg_l com4 6 seg_m	SEG21	48	23
pin_27	function/plane digit segment com1 5 seg_a com2 5 seg_b com3 5 seg_c com4 5 seg_p	SEG16	53	28
pin_28	function/plane digit segment com1 5 seg_h com2 5 seg_g com3 5 seg_l com4 5 seg_m	SEG17	52	27
pin_29	function/plane digit segment com1 4 seg_a com2 4 seg_b com3 4 seg_c com4 4 seg_p	SEG12	57	32
pin_30	function/plane digit segment com1 4 seg_h com2 4 seg_g com3 4 seg_l com4 4 seg_m	SEG13	56	31
pin_31	function/plane digit segment com1 3 seg_a com2 3 seg_b com3 3 seg_c com4 3 seg_p	SEG8	65	40
pin_32	function/plane digit segment com1 3 seg_h com2 3 seg_g com3 3 seg_l com4 3 seg_m	SEG9	64	39
pin_33	function/plane digit segment com1 2 seg_a com2 2 seg_b com3 2 seg_c com4 2 seg_p	SEG4	70	45
pin_34	function/plane digit segment com1 2 seg_h com2 2 seg_g com3 2 seg_l com4 2 seg_m	SEG5	69	44
pin_35	function/plane digit segment com1 1 seg_a com2 1 seg_b com3 1 seg_c com4 1 seg_p	SEG0	74	49
pin_36	function/plane digit segment com1 1 seg_h com2 1 seg_g com3 1 seg_l com4 1 seg_m	SEG1	73	48