[30.6.2013]

TOAD4 - RC8.1 Errata

TOAD4 RC8.1 board has three errors that need re-working.

Header J9 pin 10 is not connected

Header J9 pin 10 should have been connected to adjacent J9 pin 5 so that if/when header J9 is mounted on the solder side of the board the AUXIN- signal is connected to the front panel DE9 pin 5.

This can be corrected by bridging pins 10 and 5 of J9 on the PCB with solder.

If J9 is mounted on the component side this fix is unnecessary.

Because this AUX INPUT feature is not currently implemented in software and is thus not used this fix can be left undone.

Resistor R6 is connected to +12 V

R6 which is the pull up resistor for the optically isolated AUX INPUT should have been connected to +5 V but is wired to +12 V.

This can be corrected by leaving the +12 V end of R6 (6.8 kOhm) not connected and wire it to the nearest +5 V or by using a 15 kOhm resistor for R6 which limits the input current to the PIC input pin to a safe level.

Also because this AUX INPUT feature is not currently implemented in software and is thus not used the R6 can be just left out.

+12 V is short circuited to GND near R28

Because of PCB layout and design rule check error the PCB trace leading to R28 is short circuited to the ground copper pour on the solder side of the board.

This needs to be corrected by disconnecting the trace from the copper pour.

The easiest way to do this is to cut the trace leading to R28 on the solder side and wire R28 as illustrated below (left picture):

(click for a larger picture)

Header labels U10 & U11 are crossed

The header labeled U10 is actually U11 and vice versa.

These headers/jumpers are used to configure the drive current for X-channel motor.

The PCB layout for X-motor is correct so it is only necessary to keep this in mind when inserting/soldering the jumpers and rely on physical layout of the jumpers which is correct and identical in all motor drivers.

ICSP not compatible with PICKit 3

The connector J5 pin 2 needs to be connected to Vdd in order for the ICSP to work with PICKit 3. PICKit 2 works with or without this connection. Vdd is available a the other end of R12, the end which is not connected to the J5 pin 1.