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Finger Board assembly instructions.

Construction notes: This kit requires good soldering techniques due to its small size.
Tools necessary: A fine tip soldering iron and a good wire cutter.
Recommended tools: Mechanical clamp-known as a third hand, fine solder wick to remove excess solder.

Caution: Integrated circuits are static and heat sensitive. Do not apply too much heat with your soldering iron when installing these parts. Please take precautions while handing IC's. To protect against static electricity, ground your body before handling these parts.

Finger Board parts Finger Board parts list.
Schematic in Acrobat PDF format.
Manual in Acrobat PDF format. This is a large file, about 1.2megs.
A Windows Help file to facilitate connections.
Silkscreen and parts placement layout
Frequently Asked Questions FAQ list.
Step 1 Step 1

Start by installing the IC's. Observe proper orientation for pin 1. You may install an IC socket for U7 and U8 but do not socket U5. The installation of a socket for U5 will interfere with U3, the 256kbit ram, which will require the need for a socket. We normally do not install sockets for these IC's.

U5 - 74HC573
U7 - 74HC138
U8 - 74HC00

Note: On the parts list, there is a second part also referenced as U8. This is a MAX232 IC that is to be installed on the Communications board. Do get this mixed up with the 74HC00 IC that is installed here.
Step2 Step 2

Install capacitor C6 and the 28 pin IC socket for U3. You may need to snip off the center plastic section of the IC socket so it will fit over U5.

C6 - .1uf monolithic capacitor. The printed value on the capacitor will normally be 104, denoting a .1uf value.
U3 - 28pin IC socket
Step3
resister
Step 3

Install the resistor R1, R2, R3, R5 and R6. Bend the resistor as shown on left so that it may stand end up on the PCB.

R1, R5, R6 - 10K ohm
R2 - 47K ohm (a 10K ohm may be substituted)
R3 - 1 Meg ohm
Step 4 Step 4

Install the 52pin PGA IC socket for U4. Observe proper orientation for pin 1 before soldering.
Step 5 Step 5

Install resistor R4. This is a bussed 47K sip resistor. Observe proper orientation for pin 1 before soldering. Pin 1 is usually marked with a dot. You may end up with the more common 9 resistor sip package, just cut off the last pin (pin10) before installation.

R4 - bussed 47K ohm sip resistor.
Part # 9-1-473 or 10-1-473
Step 6 Step 6

Install capacitor C3 and C4.

C3, C4 - 22pf capacitor (20pf may be substituted)
Step 7 Step 7

Install capacitor C1, C2, C3. Observe the polarity for C1 and C13. Place positive side closest to the silkscreened "+" symbol.

C1 - 1uf tantalum, 25 volts or greater
C2 - .1uf monolithic. The printed value on the capacitor will normally be 104, denoting a .1uf value.
C13 - 10uf tantalum, 6.3 volts or greater
Step8crystal Step 8

Install crystal Y1. Cut a small piece of Mylar or thin cardboard insulation to prevent a short on the pc board. Punch two small holes for the crystal leads so the insulator can fit against the bottom.

Y1 - 8Mhz crystal
Step 9 Step 9

Install reset IC U1 and 5 volt regulator U2. Observe the silkscreened symbols on the PCB for proper placement.

U1 - MC34064 (Motorola)
U2 - LM7805

A low drop-out (LDO) voltage regulator can be substituted for the standard LM7805 regulator. Applications that require low current use such as a solar cell powered Finger Board or running off 4 cell batteries may need a LDO regulator.
Step 10 Step 10

Install capacitor C5.

C5 - .1uf monolithic capacitor. The printed value on the capacitor will normally be 104, denoting a .1uf value.
Step 11 Step 11

Install capacitor C7 on the bottom side. Bend the leads over and cut to short length before soldering.

C7 - .1uf monolithic capacitor. The printed value on the capacitor will normally be 104, denoting a .1uf value.
Step12header Step 12

The following headers are normally installed on the top side of the Finger Board. Depending on your actual application, these headers can be placed on the bottom.

Headers are usually purchased in longer lengths (shown left) and cut down to the size needed. Use headers with a contact lead length of .230"(shorter style).

JP1 - Header 4x1. This should be a connector with a key to prevent installing backwards since this is where the Finger Board gets its DC input supply voltage.

JP2 - Header 7x2
JP6 - Header 2x2
JP10, JP12, JP13 - Header 2x1
JP14 - Header 3x2

Note: If you have the Finger Board PCB with attached communications board, you can hardwire JP15 and JP14 together. An easy way to do this is to hardwire one row from the top and the second row from the bottom of the board. Just make sure pin 1 goes to pin 1, etc. Be careful of shorts when placing the wires.
Step13 Step 13

The following headers are normally installed on the bottom side of the Finger Board so that prototyping boards can be used. Depending on your actual application, these headers can be placed on top.

JP4 - Header 4x2
JP7 - Header 8x2
JP9 - Header 9x2
JP11, JP8, JP16 - installed as one Header 11x2
Pull-up resister Step 14

For “Interactive C” users who intend to run Finger Board without the Communications board connected.

Once you remove the Communications board, you must short pin 1 to pin 6 on JP14. You are essentially tying the receive pin high. You must remove this short when you connect back the Communications board. Without this connection, receive pin is left floating, your program might stop because of electrical noise. Interactive C is continuously polling the receive pin for commands. If it thinks a command is sent, it will then wait for a complete message while your program is stopped. You can create a modified IDC ribbon cable connector with pins 1 and 6 connected. Use this to plug into JP14 once the Communications board is disconnected. A more permanent solution is to solder a 10K pull-up resistor between pins 1 and 6 of JP14 on the bottom side of the board. If you leave the Communication board connected you will not have any of these problems.

The 10 K pull-up resistor is shown with heat shrink tubing surrounding the resistor to prevent shorts.
top Step 15

You should wash and clean the completed board before installing U3 and U4. We use water soluble flux solder here at EAS. This permits easy board cleaning. Radio Shack sells flux removing solvent made for pc board cleaning. Take a close look at all solder joints and touch-up any joints that look bad. A 2x or 3x magnifying glass helps to find any solder bridges.

When installing the 68HC11 cpu, observe pin one polarity. It should easily be pushed in. Also observe proper pin placement when install the memory module.

U4 - MC68HC11A1FN CPU
U3 - DS1230AB/Y Dallas 256kbit (32Kbyte) battery backed static ram. Substitute a DS1244Y if a real time clock is needed. You can also use a Dallas DS1216D 28pin lithium battery socket but will need separate 256kbit 62256-100LP static memory chip

Some 52pin PGA sockets are wider than normal and the memory may not be able to fit correctly. Place a second 28 pin IC socket on top of the first to raise the memory so it can clear the right edge of the PGA socket.

Place a couple of jumper shunts on JP6. This is the A/D reference input voltage. Install a shunt across pins 1 and 2 to tie VRH to 5 volts. Install a shunt across pins 3 and 4 to tie VRL to ground.
Step 15 Step 16

Install U8 on the Communications printed circuit board. Observe proper orientation for pin 1. If you want, you can install a IC socket for U8.

U8 - MAX232CPE (Maxim)
Step16 Step 17

Install capacitors C8, C9, C10, C11, C12. Observe the polarity of the capacitors before soldering.

C8, C9, C11, C11, C12 - 10uf tantalum 16 volt. 1uf tantalum can be substituted due to the newer MAX232 specifications.
Step 17 Step 18

Install resistor R7 and LED D1. The shorter lead on LED D1 is the cathode. If D1 is installed backwards, the communications board will not operate. Place the cathode side of the LED to line up with the silkscreened bar on the PCB.

R7 - 1K ohm
D1 - HLMP1790 LED

The LED is rated for 2ma. If a higher current model is substituted, the Communications board will not work. You can decide not to install the LED, since it just indicates download mode. The download mode will also be indicated on your computer screen while Interactive C is sending out the pcode.
Step 18 Step 19

Install switch S1. This is a momentary push button switch that is normally-open.

S1 - Momentary normally open push button switch.
Step 19 Step 20

Install connector P1 and header JP15.

P1 - Female DB9 pin connector
JP15 - Header 3x2

Note: If you have the Finger Board PCB with attached communications board, you can hardwire JP15 and JP14 together. An easy way to do this is to hardwire one row from the top and the second row from the bottom of the board. Just make sure pin 1 goes to pin 1, etc. Be careful of shorts when placing the wires.
IDC Step 21

To connect the main CPU board to the Communications board, you will need a short length of ribbon cable and two female IDC connectors (3x2). When making the cable, make sure pin 1 line up together on both connectors. The ribbon cable length should be no more than 1 foot or communication errors may take place.
LCD Step 22

When using Interactive C, the Finger Board supports a 16x2 line LCD module connected to header JP2. To connect the LCD module, you will need a short length of ribbon cable and two female IDC connectors (7x2). When making the cable, make sure pin 1 line up together on both connectors. The ribbon cable length should be no more than 1 foot.

If you cannot locate a LCD module, you can purchase one directly from EAS. The cable is included in the price.