MF PROJECTS HOME TECHNICAL TIPS MOBILE SITE
PIC Projects
WiFi, Ethernet
Doorbell with SD / EEPROM
SD FAT16/32 for .bmp
TFT Egg Timer
LCD TFT Oscilloscope
SD Talking Clock
SD Sound Recorder,
    FAT32 wav Player
LED Thermometer
LED Egg Timer
LCD Egg Timer

Frequency Counters
TFT 10MHz
100KHz For PC
1MHz For PC
8 Digits LED 50 MHz
Scope Screen Display
LCD Module 10MHz
6MHz for Android
USB PIC18F2550
USB TFT display BMP
USB DS18B20 Sensor
USB Thermometer
USB Counter
USB Meter
USB Oscilloscope
USB Input-Output
USB 16x2 LCD

COM & LPT Ports
MCP3201 on LPT
Serial TFT Text
Serial Inputs Outputs
Serial Port LCD
Analogue Signal to LPT
MCP3201 on Serial Port
Serial Thermometer
Analogue Signal to Serial
LCD Display on LPT
Serial Thermostat

Others
Water Softener
HP Stream 7 docking
3.7V to 5V
Solar Charger

Infrared Decoder
PIC Music

Code Lock
Code Lock with LCD

USB FREQUENCY COUNTER AND VOLTMETER

Using PIC18F2550 for connecting analogue and digital signals to USB port . Included Visual Basic 6 code, Visual Studio 2005 C# code, PIC ASM code, PIC C code and a circuit diagram. The PIC microcontroller has 10 bit analogue to digital converter, by selecting 8 bits conversion the 2 LSB are ignored. The circuit is powered by the USB. The interface to the PC is HID class.
The frequency counter has a range of up to 4MHz (24bits). Inputs samplings can be done at rates of 1 per second and 1 every 0.1 second.
HID class (human interface device) is a class of devices like the mouse and the keyboard, the data transfer rate is limited to 64KB/S. The PC already has a driver for HID USB.
C# code is modified Microchip code from the USB framework, Microchip Solutions v2012-04-03.
VB6 code
includes guidance to setting up the PC. The PC register the PID and VID (product ID) of the USB device when it's plugged, the VB code uses these ID's to communicate with the device. For commercial VID it is needed to buy it from USB-IF, but in your lab you can use any number.
The source code is derived from freeware from these sources:
http://janaxelson.com/usb.htm , http://openprog.altervista.org/USB_firm_eng.html
You are free to use the circuit diagram and the VB software with no limitations.

USB FREQUENCY COUNTER AND VOLTMETER FOR ARDUINO

Using PIC18F2550 for connecting analogue and digital signals to Arduino USB port . The Arduino USB port is easily accessed by imitating keyboard mainly because it saves coding in java, a language I can't learn. 
PIC C code is Microchip sample code for USB Keyboard. The file Keyboard.c has the added code for the ADC and the frequency counter from line 900.  The USB sends 1 bytes at a time for each key, the 11 digits of the counter and voltage are sent in 30 bytes. The HEX file is included, the c code can be compiled using C18 v3.43 with MPLAB.
The Arduino app is in BASIC! graphic text. http://mougino.free.fr/rfo-basic/index.html . The app uses graphic screen to displays voltage and frequency. The .apk file is the file that installs manually the app to your phone. For editing the app the .bas file can be imported after you install the RFO BASIC app to your PC and or your Arduino device.
HID class (human interface device) is a class of devices like the mouse and the keyboard, the data transfer rate is limited to 64KB/S. The PC already has a driver for HID USB.

You are free to use the circuit diagram and the software with no limitations.

The Arduino App

The VB6 application is a combined digital and analogue voltmeter.

Circuit Description
See also Technical Tips

PIC18F2550
Pin 3 is the analogue input, voltage range 0 to 5V. Max input voltage is 5.5V .
Pin 11 is the counter input, TTL voltage levels.
Pin 14 is 3.3V internal supply for the USB transceiver. 0.22uF is required for regulation.
Pins 15,16 are the data lines to the USB connector on the PC.
Pin 20 is the PC 5V powering the PIC. It is limited to 100mA by the PC. 0.47uF is for decoupling.
For USB wiring info: http://www.interfacebus.com/Design_Connector_USB.html





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