BOB-4 Quick-Start Guide ~ Copyright © 2012 by Decade Engineering ~ Page 2
Cautions!
Be certain that you have a stable 5VDC power supply, regulated to ±5% or better, BEFORE proceeding with
BOB-4 operation. Applied voltage must never exceed +5.500V under any circumstances, however briefly.
Excessive voltage and poor regulation can damage the BOB-4 module, and such damage is not covered by
the warranty. Power supply voltage overshoots must not occur at turn-on or turn-off time, or when power
supply load conditions change. Application circuits should include an electrolytic bypass capacitor of
100~470uF near the +5V power supply input pin to BOB-4. Switch-mode power supplies should include at
least one extra L/C filter stage beyond the basic L/C components required for operation. Residual switching
spikes should be suppressed to no more than 10 millivolts at BOB-4’s power supply input pin.
BOB-4 Hookup
Header Connectors for BOB-4H
Here are a few example part numbers for ‘BergStik’ style male pin headers to mate with BOB-4H. These are all
conventional THT (thru-hole technology) 40x2 pin headers with .025” square pins and .100” spacing that divide into
a pair of 20x2 headers:
NSH-80DB-S1-TG (Robinson-Nugent)
2380-6121TG (3M)
517-6121TG (Mouser)
PH2-80-SGA (Adam Technologies)
SIMM Sockets for BOB-4S
Jameco catalog number 100302 has been tested with good results. 30-pin SIMM sockets are bundled with BOB-4S
modules sold by Decade Engineering when the purchase quantity is 1~9 (only). Additional sockets may be ordered
under Decade Engineering part number SIMM-30.
Hookup Notes
The drawings below show typical BOB-4 hookups to a PC using the asynchronous serial ‘TTL-232’ main port at
9600 bps. Many additional BOB-4 features are available through hookup options explained in the BOB-4
Application Guide. One option that can be especially useful during application development is a hookup to BOB-4’s
debug port, which is easily implemented with unused portions of the RS-232 interface IC in these drawings.
ACR0~ACR3 and CTSI are configuration shunt options. Install ACR3 and CTSI shunts or wire as shown.
BOB-4’s primary ground pins must be linked through a PCB ground plane or other very-low-impedance connection.
Use 22 AWG or larger wire (or multiple wires) in hand-wired installations.
PC COM port pin assignment is for a standard male/female 9-pin modem cable with all pins wired straight through.
This hookup will not work with null-modem cables. The PC’s data flow control signals are looped back in these
examples, so that PC application programs may ignore handshake setup issues. The only PC COM port
connections actually required are serial data in/out and ground. BOB-4 does support hardware and software flow
control schemes, however.
Analog Devices’ ADM3202ANZ is supplied in a conventional DIP-16 package (available from Decade Engineering).
Substitutions are available from other manufacturers, but older RS-232 interface chips that are not specified for use
on 3.3V power will not work correctly.
