Very Easy Single Side PCB for
Easy-Downloader V2.2
        Original version by Wichit Sirichote at   Easy Downloader V 2.0.
Upgraded version by Puiu

    The upgraded part is only the PCB, the software remains the same as in original project which you can find at  Easy Downloader V 2.0
    Here you have a single side version of PCB of the Easy-Downloader V2.0 (by Wichit Sirichote). The board is 8.5x7cm 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, also one LED (red) for 12/5Vcc, 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]. All can be easy done in ONE SIDE PCB with only 1 (one) strap! 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 40 pins IC to see if it match over the holes, once is matching, the other parts will also do, and you can print it or use the pcb file which is included] 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). Take care for short circuits! A good ideea is to mount all 3 ICs on sockets (Master, Slave - of course! and MAX232), in that case if something is going wrong is very easy to replace the defective part! Also, there are some parts which are mounted under the Master and Slave uC, so you can mount them below (inside) the uC socket. The power supply for the programmer is somewhere at +15Vcc and the input is via a bridge diode. 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  R12V and R5V (5k and 2.5K pots). Better disconnect power supply before manipulating uC!

Figure 1: Circuit Diagram of Easy-Downloader V2.2

Figure 2:     An PCB Overview from component side
(blue=bottom layer, red=top layer or strap, yellow=components[silkscreen overlay])
[click to enlarge]

Figure 3:   PCB bottom layer overview (from component side) and holes
[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 ready-to-run board overview

Also here you have the PCB (Protel 2.7.1) easy52.pcb
Here is the BIN file for AT89C51 Master

Visit Easy Downloader V 2.0 (original file)
For any questions and more details email to Puiu