How it Works
USB-Mini Connector, this provides both the power and the serial data communication from the computer to the Reactor Core programmer.
USB/Serial FT232RL, the communication IC chip by FTDI. It converts the USB signal to 5 volt TTY serial for the
microcontroller level communication.
S1-Power Switch, simple 2 pole single throw slide switch. It connects the 5 volt line on the board to the 5 volts
from the USB-Mini connector. After the switch are a 500mA PTC and a 5.5 V varistor for circuit protection.
Power On LED, this LED will light up once the power is switched on.
Comm. LEDs, these LEDs are powered by the FT232RL chip. They indicate the direction of the communication.
Serial Header, the header connects directly to the FT232RL chip.
Jumpers-Serial, from the serial header there is a set of jumper points to the internal ATmega328P chip. The TX line requires a jumper. Serial communication out from the header must have the TX jumper removed; otherwise the communication from the internal ATmega328P will interfere. Leaving the RX jumper in place will write data to internal ATmega328P, but this does not affect external programming. The RX line has a trace that can be broken.
ISP Header, In-System Programmer interface is a communication interface used by Atmel for many of their
S2-PROG. Direction, the ISP header can be used to either bring the signal into the internal ATmega328P for burning its bootloader, or it can switch to send out the signal to the header and ZIF socket. The reset line is what has to change from RESET for incoming signals to pin 10 for outgoing signals.
Internal Atmega328P, this is the 32-pin TQFP version of the microcontroller used on the Arduino Uno board. It uses the same device ID for burning bootloader as the Uno.
S3-Device Selector, this 16 pin switch swaps which inputs go to the ZIF socket. Left is for the Atmega328P. Right is for both the ATtiny 84 and 85 microcontrollers.
S4-ATtiny85-Xtal, this switch makes the second crystal connection between Q3 and the ZIF. All other connections are done with S3. This should be switched to the left for programming ATmega328P.
Chip Insertion Graphic, a pictogram that shows which direction the microcontrollers should face and where to
install the ATtinys.
When soldering SMD (surface mounted devices) electrical components, you should start with the smallest parts first and if possible work your way from one side to the other or top to bottom. This would usually mean starting with the resistors and ceramic capacitors.
For hand soldering, always keep the soldering iron wetted with some fresh solder. When you press against the part with a soldering iron it will want to move. It is best to fix one end before soldering the rest. One method is to melt a little solder onto one of the pads. Then place the part and hold it over the pads. Use your soldering
iron to heat both the part and the solder below. Once you have one pad soldered and secured, it is easier to solder the rest in place normally.
If you have any have any solder bridges, this is especially true when working with parts with multiple small pins, add flux to the pins and use solder braid/wick to draw off the extra solder.