This is revision A of the Voice1 module.
The Voice1 module provides a way to record and play back voice quality audio.
This design is pretty much a complete knock-off from an article written by Jack Buffington in the July 2006 issue of Servo Magazine pages 57-59.
Command
NameBit Action Description 8 7 6 5 4 3 2 1 0 Common
Commands0 1 1 1 1 1 1 x x Send Standard common command. See specifications for details. 0 a a a a a a a a Receive Select 1 a a a a a a a a Send Select the module with an address of aaaa aaaa. A time-out indicates that the module is not selected. (FIXME: 0xa5 is currently returned.) 0 0 0 0 0 0 0 0 0 Receive
The hardware consists of a circuit schematic and a printed circuit board.
The parts list kept in a separate file -- voice1.ptl.
The schematic for the Voice1 module is shown below:
As usual, the the RoboBricks CAN bus signals come in on N1-5 and N1-6 and are routed to the CAN bus physical layer IC U2 (MCP2551) on pins U2-7 and U2-6. The transmit and receive signals are routed between U2-4 and U1-5 and also between U2-1 and U1-6, where U1 is PIC16F688 microcontroller running at 20Mhz via the ceramic resonator (X1). The voice playback chip is an ISD4003 (U3) that runs on 3.3 volts supplied from VR1 (LP2950CZ-3.3). The signal to be recorded comes from N2 and is routed into U3-17 and U3-16. The output signal comes out via U3-13 and is attenuated via the voltage divider R1 which acts as a volume control for the audio amplifier U4 (LM386). The output U4-5 is routed to either the on board speaker SP1 via a jumper that shorts J1-1 and J1-2 together or it is routed to N3-1 and N3-2 by shorting together J1-2 and J1-3. There are 6 control wires running between the microcontroller (U1 pins 8-13) and the record chip (U3 pins 1-3, 24, 25, and 28.)
The printed circuit board files are listed below:
The following files are available:
The following fabrication issues came up: