The upgraded part is only the PCB,
the software remains the same as in original project which you can find
at Easy
Downloader V 1.1
Here you have a single side version
of PCB of the Easy-Downloader
V1.1 by Wichit
Sirichote. The board is 10x4cm in a full size. That new
PCB has some small modifications comparing to original scheme. It has an
MAX232
(or similar) instead of DS275, one LED (green) for 5Vcc indicating
(instead of straight voltage in), also one LED for write process
(red LED on the right top of PCB), one DB9F connector for serial
access (can connect here a serial DB9F to DB9M cable [3 wires, pin 2 to
pin2, pin 3 to pin 3, pin 5 to pin 5] - that connector can be removed
if not needed, board can be cutout following the light blue line between
the DB9F connector and rest of the board, in that case you will solder
the wires on 3 pins small RS232 connector which is in the top-left side
of the board), reset switch for Master uC (can connect a switch at X1 SIP
connector (top middle) for reset operation).
All can be easy done in ONE SIDE PCB with only 3 short straps! I recommend
to print the GIF picture (using a laser printer at least 300DPI) at right
scale (you can do some experiences on normal paper to find the correct
scale for printing [you can place over the holes on the paper an 20 pins
IC to see if it match over the holes, once is matching, the other parts
will also do, and you can print it and print it on a full transparent UV
sheet of plastic (transparent plastic sheet for laser printers will be
OK) and than, using the Positive spray technology (spray, UV exposure,
developing, etching), to transfer the GIF on the copper side of board (the
GIF is bottom side view from top, so, turn it [mirror] before put it on
board).
Also, the board can be done by hand draw, taking care about inter-pins
crossing tracks. Take care for short circuits! A good idea is to mount
all ICs on sockets (not only the slave uC, but also the rest), in that
case if something is going wrong is very easy to replace the defective
part! Also, there are 2 parts (R11 and D4) which are mounted under the
Master uC, so you can mount them below (inside) the uC socket or, if not
possible, you can mount them on the other side of PCB (bottom side).
The power supply for the programmer is somewhere at +15Vcc and the input
is protected with a 1N4001 diode for reverse polarity. Around LM317 are
3 resistors which require very precise values, I had not, so, I tried and
combined several parts until I measured right voltages (+12Vcc +/-0.5 when
2N2222 is OFF and +5Vcc +/-0.1 when 2N2222 is ON), you can also put 2 pots
instead of R2 and R3 (5k and 2.5K pots). Better disconnect power
supply before manipulating uC! Also, Zener diode between base of 2N2907
and ground is optional (if it exist, we'll have always 12Vcc/5Vcc on pin
1 of ZIF socket, so, better without; reason for that diode is to stop the
12Vcc go to LS373, but not necessary). LS373 chip is pin 1 down (!), cause
of easier PCB in this way...
Figure 1: Circuit Diagram of Easy-Downloader
V1.2
Figure 2: An PCB Overview
from component side [click to enlarge]
(blue=bottom layer, red=top layer or straps,
yellow=components[silkscreen overlay])
[click to enlarge]
Figure 3: PCB bottom layer overview
(from component side) and holes (185 pads)
[click to enlarge]
Figure 4: Bottom layer
in 2 colors, ready for printing
Click on image for good resolution GIF ready
for printing
Bottom layer is viewed from component side
(top)
[click to enlarge]
Figure 5: An components
side overview, straps (or top layer=red) and components values
[click to enlarge]
Figure 6: An ready-to-run board overview
Also here you have the PCB (Protel 2.7.1) easypuiu.pcb
Here is the BIN file
for AT89C2051 Master
Visit 
