ARMweb Pin Diagrams

Rev 4 and 5

32 pins available to the user, 5 of which can be analog inputs, and one dedicated analog input

With Rev 4 the pin numbering for the ARMweb will reflect the assignment native to the LPC2138. The revision of the board is etched on the backside of the board.

IO7
IO8
IO9
IO10
IO11**
IO12
IO13
IO15
IO17
IO18
IO19
IO20
IO21
IO22
IO23
IO25
--
IO27
IO28
IO29
IO30
IO31++

TXD1
RXD1

AD4, DAout
AD5
AD0
AD1
AD2
AD3

IO7 is connected to LED and PUSHBTTON
as an input the push button is 0 when pressed

**IO11 is open drain when an output (i.e. can not pull up)

IO15 also controls LED (when low, the LED will be lit)

Input/Outputs -- user controlled
0-3.3V level, 4mA drive when configured as Outputs

5V tolerant - use limiting resistor when connecting to a 5V supply

AD5 is always an analog input, IO26 does not exist

10 bit A/D inputs
when used as analog lines, voltage levels should not exceed 3.3V

++IO31 is always an output

B0
B1
B2
B3
B4
B5
B6
B7
RW
CS

BYTEBUS

Input/Outputs -- user controlled

0-3.3V level, 5 volt tolerant, 4ma drive when outputs

this functions as a byte-wide bus with control of RW and CS

Dual Use AD pins

On reset or power up the AD pins are configured as IO inputs. To change those to analog IOs, the user must individually read them as AD(x) commands. After that they will remain analog inputs until the next reset or power up.

PWM pins -- not yet implimented

All pins can be used for the software PWM function, and <TBD> pins can be used for the hardware driven HWPWM function.

Battery Real Time Clock

The ARMweb board is designed to accept a Panasonic ML2020/H1C rechargeable Lithium battery at position BT1. This battery powers the real time clock of the LPC2138. The contents of RAM is not kept alive while running on battery, and the CPU restarts the user program in Flash when power is restored. This battery is designed to maintain power for a few days without power, and will recharge fully in about 1 day.

LED

On the beta units, this is connected to IO(16) not 15. On later units while the LED is connected to IO(7), the silkscreen shows it as connected to IO(15), and the example programs for the ARMmite and ARMexpress use IO(15). So firmware on the board allows IO(15) to also control the LED.

U6 has duplicate connections for IO(17)-IO(20). U6 is designed to accept a ULN2803.

The bottom proto area connects neighboring pairs of pins. In the top proto area near C23, neighboring triplets of pins are connected horizontally.

In addition the ARMweb can be ordered in larger quantities with a switching power supply, which replaces U4, C1 and C9 with U1, D2, L4, C1 and C9

Pin spacing

The spacing in the prototype area is 0.1" and the terminal strip row on the right side is designed for 3.5mm terminal strips.

Rev 2,3

31 pins available to the user, 6 of which can be analog inputs

The revision of the board is etched on the backside of the board.

IO0 IO1 IO2 IO3 IO4 --- IO6 IO7 IO8 IO9 IO10 IO11 IO12 IO13 IO14++	AD0 AD1 AD2 AD3 AD4 AD5	Input/Outputs -- user controlled 0-3.3V level 4mA drive when configured as Outputs 5V tolerant - use limiting resistor when connecting to a 5V supply 10 bit A/D inputs when used as analog lines, voltage levels should not exceed 3.3V ++IO14 is always an output AD5 is always an analog input, IO5 does not exist
IO15		Input/Outputs -- user controlled controls LED (when low, the LED will be lit) as an input also connects to the push button (0 when pressed)
IO16 IO17 IO18** IO19 IO20		Input/Outputs -- user controlled 0-3.3V level, 5 volt tolerant, 4mA drive when output **IO18 is open drain when an output (i.e. can not pull up)
BUS0 BUS1 BUS2 BUS3 BUS4 BUS5 BUS6 BUS7 BUS-RW BUS-CS		Input/Outputs -- user controlled 0-3.3V level, 5 volt tolerant, 4ma drive when outputs this functions as a byte-wide bus with control of RW and CS