I have designed many small footprint PIC projects (such as, pocket watches and wristwatches) but I cannot make them really portable. To make them portable, I need small power sources. Of course, Coin Cell battery would be the smallest DC source that I can buy. The problem is that a Lithium button cell provides 3 V. which is not enough to drive my projects. I thought about using DC-DC step-up converter to boost 3 V. to 5 V. However, it’s a little bit complex to add DC-DC converter to the projects. Moreover, my projects consume a lot of power as they consist of many LEDs, a button battery will not last for a day. So, I stopped my think at that point.
USB Coin/Button Cell Battery Charger - [Link]
bidouille.org writes: [via]
The Kvarts DRSB-01 (Кварц ДРСБ-01) is a simple consumer Geiger counter. It does not feature a display of any kind like most modern Geiger counters do, but instead each particle detected by the tube make a very characteristic “click”. It was manufactured in the early 1990′s and is not made any more, but you can still find it commonly on places like eBay. I got mine for about 15€ a few years ago, but unfortunately prices have skyrocketed recently after the events in Fukushima brought back the reality that is radioactivity into everyone’s minds.
Geiger Counter USB Hack – [Link]
Here is an easy an popular way to start using USB in your designs without going into learning the complicated USB protocol. This circuit converts normal USART signals from any microcontroller into USB compatible signals which can be directly connected to the PC. If u r designing a circuit and u need pc interface, then this is the best way, use USB, as the RS232 ports are disappearing from PCs and laptops very fast.
USART-to-USB converter using FT232BM chip – [Link]
Auto switching, self powered, USB to RS485 using MCP2200 - [Link]
The FTDI BFF – an enhanced FTDI Friend… [via]
The FTDI Friend is more versatile than the FTDI TTL-232R cable, but I wanted something that could do even more. Sometimes 4 UART signals just isn’t enough. So I took the FTDI Friend design and added the features I needed. All 8 UART signals and 2 CBUS signals are available on a 2×6 connector. There is also a power LED. Edge and thru-hole pads allow for a variety of connection options. Routing the board was a challenge because all the via had to be clear of the pads on the back and all the silk text.
The front of the board has a power LED and the six pin serial connection has been duplicated on rectangular pads.
The FTDI BFF – an enhanced FTDI Friend – [Link]
USB has recently become one of the most popular types of communication for devices ranging from consumer products, to industrial robotics and test equipment. The protocol relies heavily on constant contact with devices for error checking which makes it a bit cumbersome, but the end result is stability and high through-put speeds that operating systems love. With such popularity, understanding how to communicate with a USB host (like on a laptop) becomes an essential piece of information for anyone wishing to build a USB enabled device.
Simple PIC USB Interface – [Link]
Below you see the specifications of the instruments. If you are familiar with oscilloscopes you will see that the DPScope has pretty much all the features you’d expect from a decent lower-end instrument.
If you aren’t a number freak, feel free to skip this page as fast as you can
On the next page I’ll discuss a few of the key specifications.
DPScope – Build Your Own USB/PC-Based Oscilloscope – [Link]
MichaelZ writes: [via]
While poking around SparkFun’s website I found USB Host Shield which is only marginally interesting unless you are an Arduino fan. But the USB host controller chip is interesting. The MAX3421E is a USB Peripheral/Host Controller with SPI Interface. This is an alternate to the FTDI VNC USB host controllers. It has only one USB port vs the FTDI two but for some applications it maybe the way to go. For example it could be used with a CPLD or FPGA as a USB Host. A SPI master is easy to implement in a CPLD/FPGA (similar to the dual ’595′s example). In VHDL a simple state machine could do all of the register control.
MAX3421E USB peripheral/host controller with SPI interface – [Link]