At the beginning of 2018, we developed the first version of the 6-channel speaker selector using PIC16F88 MCU and ULN2803 Darlington transistor array. In this new design, we redesign it with low-cost MCU and Darlington transistor arrays. This design also provides the same functionality as the 6-channel speaker selector switch we designed earlier. This new speaker selector uses STC15W201 MCU. This MCU is a low-cost 8051 MCU designed by STC micro . At the time of this writing, the STC15W201 can obtain for less than US$ 0.8. To drive the seven segments and to control the relays, this design uses the popular 74HC595 8-bit shift register ICs. PCB of the 6-channel speaker selector. To select each speaker channel, we use pair of 12V DPDT relays. These relays interface to 74HC595 through a ULN2001D 3-channel Darlington transistor array IC. This 3-channel Darlington driver IC is functionally equivalent to the famous 8-channel ULN2003 IC. This ULN2001D version is an 8-pin IC and is av
In this project, we developed a 5.1-channel analog audio processor using PT2322 IC. PT2322 is an inexpensive analog audio processor introduced by Princeton Technology Corporation . It contains 6-channel individual channel attenuators, a 3-way tone control system for front-end speakers, and a 3D audio simulation system. Assembled 5.1-channel audio processing board. In this design, we combine PT2322 with Arduino Nano and interface it with PC/embedded computing boards through a USB port. Native GTK UI application provides to control all functions of the PT2322 IC. The Arduino Nano can directly plugin to the PT2322 module. There are three push buttons on the panel itself to control the volume and mute the audio. To reduce the cost and minimize the PCB size, we use both SMD and through-hole-type components in this PCB. The dimension of the PCB is 59mm × 60mm. The PCB of this module can directly order from the PCBWay project page . Using the PCBWay service, you can order high-qual