What is the difference between the ER21, ER22 and ER25?
The ER21 is the original development board with a PICmicro, WLAN and Ethernet interfaces. The ER22 has the following changes • An address latch has been fitted to free up some PICmicro I/O pins. • 11 PICmicro I/O pins are available on 0.1-inch pitch connector, namely RA0, RB0-RB7, RC0 and RC1. A further 3 I/O pins RC3-RC5, with power and ground, are available on another connector to simplify connection to the i2c bus. • The Microchip ICD 2 can be used for debugging, since RB6 and RB7 are unused • The PCB is 4-layer, with solid power and ground planes to reduce electrical noise. The ER25 is a power-efficient version of the ER22: • Efficient switchmode supply for the WLAN card (5-15V input, 3.
