CATkit board assembly

For a schematic, see the attachments at the bottom of this page.

• Solder the small components first: this includes
  • the output resistor network (R7=220k,R8=47k)
  • the reset resistor (R9=10k)
  • the IC power supply decoupling capacitor (C1=100nF)
  • the reverse polarization protection diode (D1=1N4004).

The resistors and capacitor are not polarized. The protection diode is. Looking at the diode's package, you can see a marker on one side. This marker has to align with the marker on the circuit board.

• Solder the IC socket (optionally), or solder the IC directly to the board.

Beware to align the IC correctly. An IC and IC socket contains a 'half moon' marker that needs to be aligned with the corresponding marker on the circuit board.

• Connect a 6-pin header to the footprint marked as SERIAL.

Given the chip is programmed with a boot monitor, at this point the board should be functional, and can already be tested. The remaining steps are optional.

• Solder the reset switch (S4).
• Connect digital inputs or input switches to the remaining digital input ports (S1-S3)
• Connect analog inputs or potentiometers to the analog input ports (R1-R5=10k)
• Connect the line-out mini jack to pin 4 and 5 of the PANEL port.

For the port connectors: Pin 1 is indentified by a bar on the silk screen. Also, the hole of Pin 1 is square.

• For standalone operation a BREAK resistor (R10=100k) needs to be installed between the serial RX pin and ground, respectively Pin 4 and 1 of the SERIAL port. This resistor needs to be mounted on the solder side of the board. There are no holes provided.

Some images to illustrate the process. Two sides of the board:

The board with the essential components: the IC socket, reset switch and its pullup resistor, protection diode, power supply decoupling capacitor, and the serial port header.

If this is your first time soldering, start with the smaller components: the capicitor, the restor and the diode.

Then solder the switch and the IC socket.

After that, solder the remaining resistors. optionally the ICD2 programming header (not necessary if you have a programmed chip), the remaining switches, the mini jack output and the rotary potentiometers.

Here is a detail for the serial break resistor necessary if you want to operate the board stand-alone. It also shows where the wires to the minijack go.