Formica Build Instructions

Elaborated instructions for building a formica robot. If the part is on the top (with the printed names) or on the bottom (without the printed names) side is noted on the List of Parts.
Also necessary are the layouts for the top and the bottom side of the PCB.

You will need a variety of tools to build a Formica:

  • soldering iron
  • fine tip and a bigger tip
  • flux
  • solder
  • solder wick
  • tweezers
  • wire cutter
  • double sided tape

For the microcontrollers a solder tip with a cavity is helpful

Most parts of the formica are surface mounted.
What you need to know about smd soldering for building a formica robot:

Some general instructions for smd soldering can be found here:

First populate the IC1 (MSP 430) and the IC2 (Battery Charger).

These chips have many pins and there are three basic methods for soldering them:

  • Use a fine tip and solder each pin separately
  • Use a bigger tip, solder all pins at once and remove the excessive solder with the solder wick.
  • Use a special tip which contains a little cavity for solder.

We recommend the later method as it produces the best result. If you don't have one of these special tips for your soldering iron the next best method is using the big tip.

Top

brezn.muc.ccc.de_lilafisch_formica_thumb_6.jpg

Careful with the orientation, the marking on the controller has to show in the same direction as given on the PCB. You can be quite generous with the flux here.

Top

brezn.muc.ccc.de_lilafisch_formica_thumb_9.jpg

Again keep the orientation in mind. On each side two pins are connected with a solder bridge. If more are connected use the solderwick to remove the solder bridges. This can get easier if you first add some more solder to the bridge.

Now most of the other smd parts with more than two pins will be populated.
If you haven't been using it already change to the small solder tip now.

Bottom

brezn.muc.ccc.de_lilafisch_formica_thumb_12.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_22.jpg

On this side there are no markings for the orientation, so have a look at the layouts or orient on the pictures.

Top

brezn.muc.ccc.de_lilafisch_formica_thumb_29.jpg

The arrow marking on the LED is supposed to point in the direction of the MSP430.

Q4-8: Top

brezn.muc.ccc.de_lilafisch_formica_thumb_31.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_49.jpg

Q9: Bottom

brezn.muc.ccc.de_lilafisch_formica_thumb_53.jpg

Special attention is necessary when soldering Q7 and Q8. I recommend starting with Q7, the pin next to R18.

Bottom

brezn.muc.ccc.de_lilafisch_formica_thumb_55.jpg

nurnbild

unmarked
C8,9: bottom
C10: top

brezn.muc.ccc.de_lilafisch_formica_thumb_61.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_64.jpg

3 black dots or yellow line
C1,2,3:bottom
C4: top

brezn.muc.ccc.de_lilafisch_formica_thumb_74.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_77.jpg

1 blue mark
top

brezn.muc.ccc.de_lilafisch_formica_thumb_80.jpg

Resistors

The resistors are sometimes so close that you can't see at first glance which two pads will be connected by the resistor. Better check twice ;)
Some resistors are connected parallel and therefore their pads are connected. So sometimes the solderbridges are on purpose. If you're not shure check on an empty PCB.

2 red dots
top

brezn.muc.ccc.de_lilafisch_formica_thumb_83.jpg

1 green dot
top

brezn.muc.ccc.de_lilafisch_formica_thumb_r23.jpg

3 green dots or green line
R11,16,17: top
R8,9,10,12,13,14,15: bottom

brezn.muc.ccc.de_lilafisch_formica_thumb_90.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_92.jpg

3 red dots
R5,6,7: bottom
R24,25: top

brezn.muc.ccc.de_lilafisch_formica_thumb_94.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_95.jpg

1 black dot
top

brezn.muc.ccc.de_lilafisch_formica_thumb_99.jpg

1 red dot
bottom

brezn.muc.ccc.de_lilafisch_formica_thumb_101.jpg

2 green dots
R4: bottom
R1,2,3: top

brezn.muc.ccc.de_lilafisch_formica_thumb_103.jpg brezn.muc.ccc.de_lilafisch_formica_thumb_106.jpg

I reccomend changing to a bigger tip after soldering LED1,2,3

Position the LEDs so the circular part points away from the PCB (that's the actual LED, which will be used for communication between the robots)

brezn.muc.ccc.de_lilafisch_formica_thumb_108.jpg

After soldering the switch you should be careful with the vise, there is an overlap, don't break the switch.

brezn.muc.ccc.de_lilafisch_formica_thumb_109.jpg

Position the Photodiodes so the halfsphere points away from the pcb.

brezn.muc.ccc.de_lilafisch_formica_thumb_109.jpg

Optional. These Parts offer the possibility to experiment with different materials and shapes of legs.

Remove the plastic. So now you have 4 parts instead of two.
If you haven't changed yet - now you will have to use the big tip.
Make shure that the front side is pointing away from the PCB. Make a good connection between the part an the solder. The sides should be parallel to the border of the PCB or there will be short cirquits. Attach the inner parts first.

One of the corners of the sensor is flattened a bit. This corner points towards the switch (have a look at the picture).

You can bend the connectors a little more away from the motors (without breaking them…). Now add some solder in the middle of the outer pad. Attatch the motor with an angle of about 30° between the PCB and the motor. Now attach the other contact.
For the second motor do the same. The angle doesn't have to be exactly the same, the connectors give in a bit.

If you haven't done it before cut alle the legs on the bottom side of the PCB to make room for the battery (even the short legs of the switch).
Cut the wires of the battery a bit, so they are about 2cm long. Solder the contacts on. Red wire goes to B+, black wire to B-.
Be careful, never shortcircuit the contacts on the battery!
Now put some double sided tape on the PCP and attach the Battery.

final steps

Sometime now or after flashing the formica you can put some wheels on the motors and put in the contacts you want to have.

And now its time to flash the robots.

  • en/formica_hw_lang.txt
  • Last modified: 2021/04/18 12:35
  • (external edit)