This board does NOT use the CTS256AL2 text-to-speech chip. [It would seem that both SpeechChips.com and JDR still have some of these chips, though, if you're looking for some.] However, you could easily use this board to hold the SPO chip and amplifier and connect it to your own CTS circuit. All necessary pin connections do have an available solder pad for off-board connections. Additionally, there is a socket for a 12C508/9 PIC which can reduce control pin count down to 2, or even to 1. This would also allow the line-twiddling to be offloaded from the Stamp or whatever else is the master controller. I've done the bulk of the code with some debugging and fine-tuning left. Both the PIC and audio amp [LM386] are optional and there is a provision for adding either an LED on-indicator OR a separate power supply for the amp. Amp gain is 200 and seems to be adequate with 5v supply. There is some room for a trimmer cap for the crystal in case your SPO256 chip is overly sensitive to the clock stability [as one of mine is]. The board can also be fitted with a 5v voltage regulator if you can't provide it with a regulated supply. But this option is not recommended.
Click here to download the full size of the above Circuit.
Click here to download the full size of the above Image.
Design goals: Small board size [hence the nested chips] Few control lines [4] Some construction options High quality circuit board Layed out with ExpressPCB s/w. [Visit Express PCB site (Manufacturing Specifications for Production Service) for more information about their product.] Double-sided, drilled, solder reflowed 4 mounting holes on corners solder mask silk screen. Pretty small [1.5" x 2.5" (ca. 3.8 cm x 6.4 cm)] and fairly densely packed the shift register is UNDER the socket for the SPO-256 bits are clocked out from LSB to MSB This board equires a moderate level of soldering proficiency and a fine soldering iron. Uses shift register to convert serial input [NOT RS232 serial] to parallel for SPO256. Only requires 4 lines to control: C - CLK for shift register [pin 0 in circuit below] I - INA for shift register [pin 1] A - ALD allophone load for SPO256 [pin 2] L - LRQ for SPO256 [pin 3]
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: