This commit introduces support for Dallas Semiconductor (DS) 1-wire
compliant device support using an available UART device.
The principle of operation is described in the following Application
note by Maxim Electronics:
https://www.maximintegrated.com/en/app-notes/index.mvp/id/214
with help (1-wire search) from:
https://www.maximintegrated.com/en/app-notes/index.mvp/id/187
It has been tested on Galileo 2 and Edison, with 2 DS 1-wire devices,
the DS18B20 and DS2413 connected to the bus. A UPM driver for the
DS2413 is already complete and a PR will be submitted after this one.
It is important that you use a UART with CMOS/TTL level voltages
(3.3v/5v) RX and TX lines. DO NOT use standard RS232 level voltages
or you are going to have a bad day.
In order for this to work, a simple interface circuit, using a single
diode must be constructed:
(forgive my "Asciihematic" :)
-|
U|
A| TX---|<--+
R| |
T| RX-------o--------o 1-wire data bus
-|
The diode on TX is a 1N4148 (cheap and common), with the cathode
connected to TX, and the anode connected to RX and the 1-wire data
line.
The 1-wire data line requires a pull-up resistor, as the DS 1-wire
spec requires. 4.7-5K is typical for DS 1-wire buses.
NOTE: DHT-type (temp/humidity sensor) 1-wire devices ARE NOT DS 1-wire
compliant, and will not work with this code/circuit unfortunately.
Also note, this will use up one of your UARTs, which cannot be used
for any other purpose (ie: to access true UART-type serial devices).
You can however, connect as many DS 1-wire devices as feasible to this
UART, as it will function as a DS 1-wire bus master.
Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
Example now takes pin number from command line and displays gpio level
when it changes.
Signed-off-by: Henry Bruce <henry.bruce@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
Add support for UP board (www.up-board.org), scoping
the following functions available via 40-pin header:
* GPIO (via sysfs)
* UART
* I2C
* SPI
* PWM
Validated on UP board v0.2, running ubilinux 3.0
Signed-off-by: Dan O'Donovan <dan@emutex.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This works ok if executing the whole file but the node.js interactive
interpreter gets confused when yoy copy and paste the code
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
By default, CMake assumes both a C and C++ compiler are required.
This is not needed for mraa because it only provides C++ header
files. Note that if using SWIG you need one and if using node.js 3+ you'll need
a C++11 compiler
Signed-off-by: Pieterjan Camerlynck <pieterjan.camerlynck@gmail.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
- C API read/write integer functions changed to int to match C types
- C API now has close function to release resources acquired during init
- iio internal type isr_event() function now has args param in signature
- C++ API now supports events with handler interface and new data structure
- C and C++ examples updated to use API changes
Signed-off-by: Henry Bruce <henry.bruce@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
scale and other attributes have to be read individually as they vary quite alot
depending on the channel. We only care/take data from scan_elements
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit creates a new structure inside each _iio device when used and can
then be used to understand the data being read after a trigger is run/executed
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
