This analysed can be used to troubleshoot a reluctant proprietary application or to ‘reverse engineer’ existing applications. The device communicates with a PC via a USB link configured as a virtual port (COMx) and so is powered directlyfrom the USB, avoiding the need for an external mains adaptor (or even batteries).
Resistors
R1,R2 = 8kΩ2
R3,R4 = 1MΩ5
R5,R6 = 330
R7,R13 = 470
R8 = 4kΩ7
R9,R10 = 10k
R11,R12 = 1k
R14,R15 = 27
R16 = 1kΩ5
Capacitors
C1,C2 = 1nF
C3,C4,C10 = 100nF
C5-C8 = 22pF
C9 = 10nF
C11,C12 = 33nF
Semiconductors
D1 = LED, 3mm, red
D2 = LED, 3 mm, green
T1,T2 = 2N7000
IC1,IC2 = 4538
IC3 = PIC18F4520, programmed, Elektor shop item # 070600-41
IC4 = FT232BM (FTDI)
Miscellaneous
K1 = 6-way RJ-11 socket (vertical)
K3,K4,K5 = 6-way RJ-11 socket (horizontal)
K2 = USB socket, male, type B
L1 = ferrite bead
X1 = 20MHz quartz crystal, HC 49/4H case
X2 = 6 MHz quartz crystal, HC 49/4H case
S1 = miniature pushbutton
S2,S3 = ‘D6’ pushbutton (red and black)
JP1 = 3-way SIL pinheader with jumper
PCB, item # 070600-1
PCB artwork, free download from www.elektor.com
Project software (PC executable and .hex file), item # 070600-11
Informative articles
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