Step 3: PCB and partlist
The PCB is a 2-layer design with small traces and separation (10mil) around the 64pin TQFP PIC chip. We prepared gerbers and sent them to Seeed Studio's PCB service for open source works. Extra PCBs from our order are available in the Seeed Studio shop. If you buy our extra PCBs be sure to get the HanRun ethernet jack that fits the board.
Since the mounting holes on 20x4 LCDs vary, we didn't try to fit the PCB to the LCD holes. We made it as small as possible, like SparkFun's serial LCD backpack, so it stays out of the way of the original holes. As a side effect, it's not too terribly awkward behind some smaller screen like this 16x2 LCD at Adafruit.
Click for a full size placement image [PNG].
Part | Value | Package
IC1 PIC 18F67J60 TQFP-64
C1-3 10uF tantalum capacitor, 10volts+ SMC_A
C4,5 33pF capacitor 0805
C10,11,C14-23 0.1uF capacitor 0805
ICSP 5x 0.1" male pin header
J1 2.1mm SMD power jack SMD
J2 HR911105A ethernet jack RJ-45
L1, L2 Ferrite bead, 200ma+ 0805
NPN1 NPN transistor, 250hfe+, 800ma+ SOT-23
Q1 25MHz SMD crystal HC49UP
R2(A) 10K single turn trim resistor 3mm SMD or through hole
R3 240 ohms resistor 0805
R4-6 390 ohms resistor 0805
R7 2,260 ohms resistor, 1% 0805
R10-21 10,000 ohms resistor 0805
R30-33 49.9 ohms resistor, 1% 0805
VR1 LDO 3.3volt regulator (LD1117) TO-220
VR2 7805T 5volt regulator TO-220
HD44780-LCD 20x4 HD44780 character LCD