- #HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE SERIAL#
- #HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE 32 BIT#
- #HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE FULL#
- #HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE CODE#
Many switches packaged in SOT23-5 and SOT23-6 use this footprint, use On Semiconductor NCP380 as a reference. Next picture will be used to explain the details of the power control circuitry.Īrrow A points to the jumper which needs to be cut openĪrrow B shows the position where 0603 0.1uF ceramic capacitor needs to be placedĬ and D show the places for the power switches (only one switch is needed). Current revision of USB Host 2.0 library is needed to support power control. Finally, D is VBUS Power jumper which needs to be opened, as pictured. C is a wire from MAX3421E GPX pin to the ENABLE pin of the power switch. B is 0.1uF ceramic capacitor in 0603 package. A is a power switch IC (in this case, Micrel MIC2004). Also, many power switches incorporate current limiting circuitry allowing VBUS overload detection and prevention.Īn example of populated power switch is shown in the title picture (click on it to make it larger). Some other devices can’t even be initialized reliably without a powercycle. In battery-powered projects the run time can be significantly increased by powering on USB device only when needed. The ability to turn VBUS on and off at will can be very beneficial. However, if you do care about power control, read on.
The board comes with power switch unpopulated and if you don’t care about this feature it can simply be ignored. On this PCB I added a new feature, suggested by Andrew Kroll – a VBUS power switch. In order to see the characters, the display must be biased – a 5K-10K pot with wiper on Vo and other two pins on 5V and ground will provide contrast adjustment.Ĭontinue reading Adding a display to a digital scale using Arduino and USB Host shieldĪbout a month ago I started shipping USB host shields built on PCB bearing revision number 2.0.1. In addition to data lines, 5V and ground must also be connected to the shield’s 5V and GND terminals the RW pin must be grounded – I do it on the LCD itself. In this project, the LCD is connected to the shield’s GPOUT pins, as documented in max_LCD.h header file. It has been tested with Arduino IDE version 1.0.5.
#HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE CODE#
The example code is also hosted at github, as well as in ‘examples’ section of the library under ‘HID’. Scales are standard HID devices with usage table 0x8d, therefore, scales from other brands may work as well with no or minimal modifications to the code
#HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE SERIAL#
If you’re planning to use this sketch for something else, like data logging, the display is optional – all output from the scale is repeated to the serial port
Toshiba HD44780-compatible LCD display, in 16×1 or 16×2 configuration.Standard size board, such as UNO, Duemilanove or Leonardo, will work The secondary objective of this project was to demonstrate LCD support in USB Host shield library. I also wrote a small sketch which polls the scale and outputs the weight. To test this theory I made a simple setup consisting of Arduino UNO, USB Host shield and HD44780-compatible LCD display. However, since the scale is a USB HID device reading data from it should be as easy as from a joystick and Arduino board should be adequate to provide a display function for it. The scale doesn’t have a display making any kind of standalone use difficult. It is a nice little scale which works very well (much better than service itself) while attached to my workstation. I am the proud owner of Model 510 5lb digital scale. The images to the right shows both the pinout for the Teensy 3.0 as well as the Mini USB Host Shield. In order to use the Teensy 3.0 you will need to connect the Teensy 3.0 to the USB Host shield like so: USB Host Shield
#HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE FULL#
If you are planning to use a 5V microcontroller like the Arduino Uno I recommend getting the full sized version of the shield. Note it is very important than you do not connect a 5V microcontroller to the Mini variant of the USB Host Shield, as this might damage the board. Since the Teensy 3.0 is running at 3.3V no logic conversion is needed. To use the Teensy 3.0 with the library I recommend using the Mini variant of the USB Host Shield as it is much more compact and a bit cheaper too. A more detailed overview can be found at the official page. If you are looking for a ARM based board for your next project, I recommend taking a look at the Teensy 3.0. The Teensy 3.0 is created by the Paul Stoffregen which is also a dedicated contributor to the Arduino IDE.
This is a huge increase in speed if you are used to the Arduino Uno running at 16MHz.
#HOW TO USE ARDUINO USB HOST SHIELD AND BLUETOOTH DONGLE 32 BIT#
It is the Teensy 3.0 which features an 32 bit Cortex-M4 ARM processor running at up to 96MHz. I am pleased to announce that the first ARM processor is now supported by the USB Host library.