EchoMp3 v3.1

TechDesign Electronics

  last updated: February 23, 2011.

KIT step-by-step construction guide:

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 PCB, top view (picture)

These parts are already presoldered (PCB top:)

  • IC2: preprogrammed PIC microcontroller 18F46K20-I/PT
  • Micro joystick for user controls
  • ICSP connector X1
  • A coil, resistors and capacitors.

 

PCB size = 66,50 x 54.90 mm

Double sided and 100% tested PCB with plated-through-hole connections (vias.)

All holes are drilled already.

 

PCB version: January 2011.

 

 PCB, bottom view (picture)

 

These parts are already presoldered (PCB bottom:)

 

  • IC9: DC-up chip TPS61080 (for +14V OLED voltage.)

  • A diode, some resistors and capacitors.

 

 

  Step 1: PCB bottom (drawing)
Overview of presoldered components.
  • In the left red rectangle: 1 chip, 3 resistors and 2 capacitors:

     

    • IC9: DC-up chip TPS61080 (for +14V OLED voltage.)

    • R1: 100R (100 ohms) / 0402 SMD package

    • R3: 470k / 0402

    • R7: 47k / 0402

    • C50: 47n / 0603

    • C51: 33p / 0402

 

  • In the bottom yellow rectangle: 1 diode and 1 resistor:

  • D2: 1N4148 SMD SOD80C package

  • R10: 10k / 0402

 

These components are presoldered to the PCB to do the full PIC preprogramming and testing.

  Step 2: PCB bottom (drawing)
1 chip, 2 resistors and 1 capacitor

Solder these small parts very carefully. You'll probably need a lot of patience, so take your time to do it. Due to the small sizes of the chips, this is by far the most difficult part of the whole construction.

Use a magnifying glass and a very fine soldering iron to do the soldering. First pre-solder the chips by adding a bit of solder to all pins. Then place the chips onto the PCB and make sure pin 1 is well placed. The purple arrows on the drawing point to pin 1 of  the chips. On the PCB, there is a small "1" etched.

TIP#1: In case you make a short (with the use of too much solder for example) Stay cool (!) and then desolder with 3S-WICK desoldering braid.

TIP#2: Try to presolder one pad on the pcb, then place the part on the pcb with a pair of tweezers. Hold it in place with a wooden toothpick and solder on the presoldered side. Then solder the other side.

 

  • IC7: chip BZA408 (on chip marking 'Z8') Pin 1 marked by white dot and purple arrow on the drawing.

  • R21: 10R / 0402 resistor

  • R25: 0R / 0805 resistor

  • C44: 47n / 0603 capacitor

 

NOTE: please solder the components in the order as suggested here (from step 1 and on.) Some smaller pads might be impossible to solder if bigger components are solder first.

 

 

PCB, bottom view after step 2 (picture)

This is how the PCB bottom should look after these first steps.
There are various techniques to solder SMD parts.

Have a look here if you need some additional help.

TIP#3: Use some PCC (printed circuit board cleaner to get rid of the flux.) Do away of excess fluid with an absorbing paper.

  Step 3: PCB bottom (drawing)
 1 Transistor, 6 resistors and 4 capacitors.
  • T1: FMMT717 transistor
  • 5 Resistors; R15 + R26...R29: 10k / 0402
  • C17: 10F CER / 0805
  • C32: 100n / 0402

 

  • In the top  green rectangle: 2 capacitors and 1 resistor:

  • C12 and C13: 22p / 0402

  • R4: 1M / 0402

 

 

PCB, bottom view after step 3 (picture)

This is how the PCB bottom should look after these steps.
 
  Step 4: PCB top (drawing)
  Overview of presoldered components.
 

 

  • In the  blue rectangles: 1 chip and 3 capacitors:

     

    • IC2: preprogrammed PIC microcontroller 18F46K20-I/PT

    • C55 and C56: 100n / 0402

    • C45: 4,7F/25V / SMD case B

 

  • In the  yellow rectangles: 1 coil and 1 resistor:

  • L4: 4,7...10H coil / SMD case B

  • 0R / 1206 resistor to bypass the optional ON/OFF switch. Remove this resistor and replace by a switch to have this functionality.

  • ICSP connector X1 for programming and testing.

  • Micro joystick for user controls

 

 

These components are presoldered to the PCB to do the full PIC preprogramming and testing.

 

 
  Step 5: PCB top (drawing)
  3 chips.
 

 
  • IC5: LP2985-18DBV
  • IC6: VS1053 mp3 chip
  • IC8: MCP1640B; DC-up regulator chip

 

TIP#1: In case you make a short (with the use of too much solder for example) Stay cool (!) and then desolder with 3S-WICK desoldering braid.

 

PCB, top view after step 5 (picture)

 
This is how the PCB top should look after these steps.

 

 

 

 

 

Step 6: PCB top (drawing)

 1 Coil, 3 resistors and 3 capacitors.

  • In the  blue rectangle: 1 coil, 2 resistors and 2 capacitors:

     

    • L2: coil 4,7H SMD
    • R17: 976k / 0402
    • R18: 562k / 0402
    • C53: 4,7F CER / 0805
    • C54: 10F CER / 0805

    In the  yellow rectangle: 1 resistor and 1 capacitor:

     

    • R12: 0R / 0805
    • C48: 10n / 0402

     

 

 

PCB, top view after step 6 (picture)

 

This is how the PCB top should look after these steps.

TIP#3: Use some PCC (printed circuit board cleaner to get rid of the flux.) Do away of excess fluid with an absorbing paper.

 

Step 7: PCB top (drawing)

 7 resistors and 16 capacitors.

  • R5, R8 and R9: 100k / 0402
  • C6, C7, C40 and C41: 10n / 0603
  • R23 and R24: 10R / 0402
  • R14 and R20: 22R / 0402
  • C2, C3 and C25...C28: 100n / 0805
  • C4, C5, C24: 1F CER/ 0805
  • C9, C30,C31: 10...33F/6V / case B tantalum

 

NOTE: Tantalum capacitors: + is marked with a white or coloured band.

 

PCB, top view after step 7 (picture)

This is how the PCB top should look after these steps.
 
 
 

Step 8: PCB top (drawing)

 Various parts.

  • Q2: 25 MhZ crystal (through-hole.)
  • U$1: SD card connector:  press lightly on top to click in place. Solder the four corners first, then the smaller pads on top.
  • C18 and C19: 47...100F / 16V electrolytic for optimal sound quality output
  • X4, headphone connector PG203J, 3,5mm stereo
  • JP9, 8-pins display connector.

 

TIP#1: In case you make a short (with the use of too much solder for example) Stay cool (!) and then desolder with 3S-WICK desoldering braid.

 

PCB, top view after step 8 (picture)

 

This is how the PCB top should look like after these steps.

Almost done!!

Now, let's test the circuit (without display.)

  1. Insert the MMC or SD(HC) card. The MMC/SD(HC) card has to be formatted as FAT (=FAT16) or FAT32.
  2. Connect your headphones.
  3. Apply power +2V4...+3V maximum, see on the left for the polarity. RED is +  whilst BLACK is minus.

 

You're now ready to rock 'n roll ! (Or anything else you want to listen to....)

Hearing some music: great! If not: disconnect power asap and check for shorts.

 

 

PCB, top view after step 9 (picture)

If the above steps are all successful, connect the display (OLED) module.

Check up/down carefully first!! See the picture on the left for correct emplacement.

First disconnect from power and reconnect after the display has been fitted.

 

 
 
 
   

Step 10:  PROJECT BOX (picture)

 

  • In case you bought the project box: coming soon.

  • You also might want to make the joystick a little longer. You might as well put a pinhead in it...

 

 

 

That's it! Have lots of fun building it!

 
 

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