This is revision A of the AVR Adaptor Board and it is currently a work in progress.

EMDP1 AVR Adaptor Board (Rev. A)

Table of Contents

Introduction

There is a PDF version of this file available.

The AVR Adaptor Board is used to program Atmel® AVR microcontrollers. Most chips are programmed serially. The ATtiny28 is programmed using a parallel mode.

In order to serially program an AVR one of two serial programming methods is used. The SPI programming method is entered by applying 0 volts to RESET* and talking to the chip using the SPI protocol. The AVR serial programming method is entered by applying 12 volts to RESET*.

This adaptor board directly supports the AVR microcontrollers that are in 8, 20, 28, and 40 pin DIP (Dual Inline Package) packages. Any surface mount AVR microcontrollers will need an alternative adaptor; since I am perfectly happy to use DIP packaging for all of my projects that use AVR microcontrollers, I am in no particular hurry to design an adaptor for surface mount AVR chips.

My going in design decision was that there was going to be a single 40-pin ZIF (Zero Insertion Force) socket and that I would always place pin 1 of each AVR microcontroller in the upper left corner of that socket, irrespective of whether the chip is in an 8, 14, 18, 28, or 40 pin DIP package. The investigation of how this all works is done up on the index.html.

Schematics

The schematic for the AVR Serial Adaptor is shown below:

AVR Serial Schematic
The parts list is kept in a separate file.

Printed Circuit Board

The various printed circuit board files are listed below:

avr_artwork.png
The artwork (silk screen) layer.
avr_back.png
The back (solder side) layer.
avr_front.png
The front (component side) layer.
avr.gal
The RS274X "Gerber" artwork (silk screen) file.
avr.gbl
The RS274X "Gerber" back (solder side) file.
avr.gtl
The RS274X "Gerber" top (component side) file.
avr.gml
The RS274X "Gerber" mask (solder mask) file.
avr.drl
The Excellon drill file.
avr.tol
The drill rack file.
avr.ptl
The parts list (bill of materials) file.

Tables

The EMDP1 connector is listed below:

Pin Label Connected To
1 SCL Serial EEPROM
2 GND Plug Pin 8
3 SDA Serial EEPROM
4
5
6 +5V Serial EEPROM & pull ups
7
8 BD0 Program LED
9 BD1 ZIF40 Pin 13
10 BD2 ZIF40 Pin 12
11 BD3 Plug Pin 10
12 BD4 ZIF40 Pin 27
13 BD5 Plug Pin 12
14 BD6 ZIF40 Pin 28
15 BD7 Plug Pin 14
16 BD8 ZIF40 Pin 29
17 BD9 Plug Pin 16
18 BD10 ZIF40 Pin 37
19 BD11 Plug Pin 18
20 BD12 ZIF40 PIn 38
21 BD13 Plug Pin 20
22 BD14 ZIF40 PIn 39
23 BD15 Plug Pin 22
24 BD16 ZIF40 Pin 14
25 BD17 Plug Pin 24
26 BD18 ZIF40 Pin 3
27 BD19 Plug Pin 26
28 BD20 ZIF40 Pin 2
29 BD21 Plug Pin 28 (ID3)
30 BD22 Plug Pin 27 (ID2)
31 BD23 Plug Pin 30 (ID1)
32 BD24 Plug Pin 29 (ID0)
33 BD25 Ground
34 BD26 Ground
35 BD27
36 VAR1 Plug Pin 32
37 VAR2 Plug Pin 34
38
39
40

Pin Label Connected To
1 P19 ZIF40 Pin 19
2 P20 ZIF40 Pin 20
3 P31 ZIF40 Pin 31
4 P30 ZIF40 Pin 30
5 P34 ZIF40 Pin 34
6 P32 ZIF40 Pin 32
7 P35 ZIF40 Pin 35
8 GND Ground
9 P11 ZIF40 Pin 11
10 BD3 N1 Pin 11
11 P10 ZIF40 Pin 10
12 BD5 N1 Pin 13
13 P9 ZIF40 Pin 13
14 BD7 N1 Pin 15
15 P8 ZIF40 Pin 8
16 BD9 N1 Pin 17
17 P7 ZIF40 Pin 7
18 BD11 N1 Pin 26
19 P6 ZIF40 Pin 6
20 BD13 N1 Pin 21
21 P5 ZIF40 Pin 5
22 BD15 N1 Pin 23
23 P4 ZIF40 Pin 4
24 BD17 N1 Pin 25
25 P36 ZIF40 Pin 36
26 BD19 N1 Pin 27
27 ID2 N1 Pin 30 (BD22)
28 ID3 N1 Pin 29 (BD21)
29 ID0 N1 Pin 32 (BD24)
30 ID1 N1 Pin 31 (BD24)
31 P40 ZIF40 Pin 40
32 VAR1 N1 Pin 36 (VAR1)
33 P1 ZIF40 Pin 1
34 VAR2 N1 Pin 37 (VAR2)

Issues

Any fabrication issues will be listed here.


Copyright (c) 2001-2002 by Wayne C. Gramlich. All rights reserved.