Very Easy Single-Side PCB for Easy-Downloader V1.1

         Puiu Chiselita,

    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 Easy Downloader V 1.1  (original file)

For any questions and more details email to Puiu Chiselita