Printer with speaker to indicate print error conditions
View Patent ↗A printer includes a speaker to indicate print error conditions. The speaker is driven by a speaker interface that is responsive to the printer's processor. The speaker interface includes a DMA FIFO circuit that responds to DMA mediated requests, initiated by the processor programming a dedicated channel of its DMA controller, to retrieve sound files stored in memory. A digital-to-analog converter and amplifier are provided to convert retrieved sound files to an analog signal suitable to drive the speaker.
1. A printer including:
a processor;
a speaker interface responsive to the processor;
a speaker driven by the speaker interface; and
a memory device containing sound files, wherein the speaker interface includes a circuit arranged to convert the sound files into an electrical signal to drive the speaker.
2. A printer according to claim 1 including a memory containing instructions to a printer controller to control the speaker interface to indicate printer error conditions by driving the speaker.
3. A printer according to claim 1 , wherein the speaker interface is arranged to retrieve the sound files from memory on the basis of the signals from the printer controller.
4. A printer according to claim 3 , including a direct memory access (DMA) controller responsive to commands from the processor and having a channel dedicated to the speaker interface.
5. A printer according to claim 4 , wherein the speaker interface includes a DMA FIFO mediation circuit arranged to respond to requests from the DMA controller to retrieve the sound files.
6. A printer according to claim 5 , wherein the speaker interface includes an amplifier responsive to the digital-to-analog converter and arranged to drive the speaker.
7. A printer according to claim 4 , wherein the processor initiates operation of the speaker by transmitting a signal on the DMA channel dedicated to the speaker interface.
8. A printer according to claim 3 , wherein the speaker interface includes a digital-to-analog converter to convert the sound files to an analog signal.
9. A printer according to claim 4 , wherein the speaker interface is clocked at a frequency associated with the sound files.