Oricom Technologies BOT40 Features

Return to: BOT40 main page. BOT40 Controller Features

General Features

Voltage regulator
---- 5v, 1-1.5A, 7805-equiv TO-220, with heat-sink.
---- power-in connector and switch header.
---- 2nd connector-diode arrangement for charger input (can be used as brown-out prevent circuit).
CPU - 40-pin PIC, DIP package (see compatibility table)
---- main oscillator - 1 - 20 Mhz, crystal or ceramic resonator.
ICSP interface
---- 6-pin header for in-circuit serial programming (Vpp-Vdd-gnd-RB7-RB6-RB3).
CPU Port usage
---- A = analog signals and general I/O
---- B = servo control and high-current drivers
---- C = RS232, I²C, PWM to h-bridge (speed control), general I/O
---- D = h-bridge control
---- E = general I/O
EEPROM
---- layout for 8-pin I²C serial EEPROM chip, up to 32KB (eg, 24C256).
---- use for non-volatile storage of configuration, scheduling information, etc.
---- jumpers J2-J5 allow the EEPROM to be controlled by cpu pins RA4/RA5 for OOPic operation, or by the PIC internal I²C buss [cpu pins RC3/RC4].
RS-232 comms
---- MAX232-type chip with 2 transmit-receive channels, one is connected to cpu UART, and one is spare.
---- spare channel can be used for serial LCD, comm to another board, etc.

---- interface via DB09-F or HDR6 for chan-1, and HDR7 for chan-2.

- Uses of Prototyping Area -
pullups, pulldowns, series R's, zener diodes, digital chips, analog chips, opAmps, EEPROMs, speaker amps, bipolar inverters, MOSFET drivers, pushbutton switches, LEDs, sensor conditioning.

Miscellaneous
---- LEDs - layout for 4 LEDs with pulldowns to ground, non-dedicated.
---- Reset / SW1 - layouts for (2) pushbutton switches.
---- PZ1 - piezo layout, connection non-dedicated.
Prototyping Area
---- large 10x11 hole prototyping area.
---- allows custom circuitry to be added for cpu pins RA2, RA4, RA5, RE0-RE2, and RC0.
---- proto area laid out for ease of build-up, with +5v and ground busses aligned for easy addition of DIP chips, pullups, pulldowns, series R's, etc.
---- can handle up to one 20-pin or two 8-pin DIP chips.
External Headers

---- all 0.1" spacing DIL, except HDR2 & HDR5 TIL.

Having a ground pin next to every signal pin on the headers makes it extremely easy to wire sensors and effectors in such a way as to minimize inductive wiring loops and associated noise problems, since every line can use parallel, twisted, or shielded wires. This way sensors can be shielded against noise pickup, and motors + servos will radiate less EMI.

---- outer rows = all grounds on peripheral headers.
---- usable with DIL ribbon cables or header receptacles with 2 or more pins.
---- layout convenient for making multiple 2-wire (signal+gnd) connections.
---- PWR, CHG, J1 - for external power, charger, and on/off switch.
---- HDR1 = 2x11 DIL - analog & digital I/O, RS-232.
---- HDR2 = 3x4 TIL - switch closures.
---- HDR5 = 3x9 TIL - hi-current drivers, servos, plus +S power.
---- HDR3, HDR4 = 2x(2x5) DIL - h-bridge outputs, plus +M power.
---- HDR6, HDR7 = 2x(2x3) DIL - RS-232 ports.
---- ICSP = 1x6 SIL - in-circuit serial programming.

General I/O Channels - HDR1

Analog
---- up to 7 A/D channels possible, 8-12 bit cpu-dependent.
---- proto area can be used for custom signal conditioning.
Digital I/O
---- up to 19 digital I/O lines possible.
---- up to 12 lines, 0-5v input or 20 mA output (to cpu RC0, RE0-RE2, port B optional).
---- 1 line digital input or open-collector output (to cpu RA4).
---- one analog channel setup with resistor ladder network for sensing 4 switch closures (to cpu RA3).
Configurable Channels
---- 5 channels configurable as either analog or digital I/O (to cpu RA2, RA5, RE0-RE2).
---- 7 channels (cpu RA2, RA4, RA5, RC0, RE0-RE2) terminated at prototyping area, allowing addition of custom interface circuitry.

Driver Channels - HDR5

High-Current Drivers:
---- Circuitry can drive LEDs, relays, motors, solenoids, unipolar stepper motors, etc.
---- Q1-Q3 can be bipolar (pnp or npn) or MOSFET (p- or n-channel), and configured as inverters or pullups, up to 5A.
---- p-MOSFET is especially useful for switching on-off power to large external 5v loads.
---- can be powered from +5v or +S buss on HDR5.
---- driver resistors can be individually-selected.
---- controlled by cpu Port B5-B7.
---- click here for details about: High-Current Driver Hookup
Servo control:
---- HDR5 provides for direct connection of up to 8 Futaba-wired servos (signal-pwr-gnd), or 5 when using Q1-Q3.
---- +S connection on HDR4 allows for servo power separate from other busses.
Configurability:
---- provides for mix and match of port B direct I/O, driver output, and servo drive.
Header rows:
---- inner = driver out or port B out direct.
---- middle = +S power buss.
---- outer = all grounds.

H-Bridge Channels - HDR3, HDR4

circuitry can drive dc motors, unipolar and bipolar stepper motors, etc.
two h-bridge chips provide 8 separate push-pull drive channels, up to 36v and 1A each.
up to 4 complete H-bridge configurations possible.
compatible with both L293D and SN754410 chips.
channels can be tied in parallel for greater loads.
+M power provided from off-board.
8 input lines to h-bridge chips controlled by cpu port D.
the 2 enable lines to each h-bridge chip can be individually-configured, for driving from cpu PWM channels RC1 and RC2 or other cpu pins.
external H-bridges - for control of heavy loads using external electronics, port C & D pins can be wired across to HDR3 or HDR4, either directly, or by removing one or both of the on-board h-bridge chips, and replacing with a DIP header plug with the appropriate pins jumpered together.

Safety and Transient Suppression Features

Driver Load Transient Suppression:
---- layout for suppression diodes, and bypass cap.
Motor Transient Suppression:
---- L293D and 754410 h-bridge chips contain integral clamp diodes.
---- motor circuitry laidout for reservoir cap and hi-V bypass cap, plus tranzorb diode.
Power Buss Isolation:
---- 3 separate power busses total - +5v, +S (servos), and +M (motor).
---- Servos can be configured for operation off +5v buss or external +S power from HDR5.
---- h-bridge loads operate off +M power from HDR3 and HDR4.
+M and +S ground busses physically isolated from microcontroller gnd buss, with 1-point connection via ferrite or inductor.

Power

input power 8 - 15 vdc, up to 1-Amp.
power for servos is provided from off-board, via headers, normally 4.8 - 6 vdc at approx 300 mA per connected servo.
power for Mosfet loads and motors is provided from off-board, via headers, up to 40v allowable.

Physical

3.9" x 3.0" (99 x 76 mm), industrial-quality double-sided FR4 pcb with heavy buss traces, plated-through holes, solder masks and silk-screens.
mounting hole in each corner (#4 screw).

<| TOP