Produce the varying sampling clock write strobe pulses. So, I settled with this semi-optimal but working design applying an ATtiny2313 microcontroller from Atmel. For a 10MHz sampling clock, I need a 20MHz clock for the ATtiny2313and hence it needs to be powered at 5V instead of 3. 3V like all the other logic around. So, I had to add these HCT04 inverters for logic level translation of input pins; output pins
Click here to download the full size of the above Circuit.
are no big deal since both the VHC00 on the main board and the CY7C68013A on the USB-FX2 board have 5V tolerant inputs. The CKGEN_SPI 6-pin connector is the standard SPI in-system-programming connector so that the microcontroller can be programmed by my USB-AtmelPrg programmer. JP1 is the connection to the mainboard. The 8051 controller on the USB-FX2 board can program the sampling clock by taking INT1 HIGH, then transferring a command via the serial lines SCK and RxD while reading back status via TxD (also synchronized by SCK) and then taking INT1 LOW again. The clock generator outputs a constant 10MHz sampling clock on the clock0 output pin. This clock will drive the AD converter and latches at constant 10MHz at any time. Since this is also the interface clock for the USB-FX2 (USB_IFCLK), we may never change the frequency and even may never have any glitch or missing pulse. (Yes, I debugged the circuit for a whole day until discovering that a tiny glitch in the USB_IFCLK introduced by the ATtiny2313 firmware while synchronizing the interface clock with the write strobes, made the FX2 stop sending data over the USB link!) Different sampling rates are accomplished by different write strobes on the clock1 pin (USB_RDY1 which is SLWR in slave fifo mode) thereby only committing certain samples to the FIFO and hence to the USB link. So, for full 10MS/s, clock1 is simply pulled LOW, committing all samples, for 5MS/s, it is LOW...
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: