I have an Arduino with a 433mhz receiver attached. I've connected this to my computer via a usb to serial cable.
Connected to my laptop (development machine) it works fine with it (>15 metres), but when connecting it to the Raspberry pi (deployment machine) via the same USB cable the range is REALLY poor (<1 metre).
I've tried using another laptop and again it works fine. Suggesting something is wrong/different going on with the Raspberry Pi.
I measured the voltage at the 433mhz receiver and it was slightly lower when it was connected to the raspberry pi. I tried to rule this add by adding a voltage booster circuit but it made it worst if anything.
laptop = 4.88v
raspberry pi = 4.3v
raspberry pi using booster circuit = 4.98v
I've not tried an external power supply yet.
Any thoughts on what might be causing the problem?
Thank you in advance!
I connected up an external power supply to the receiver instead of using the power coming from the Raspberry Pi / Arduino. This made an amazing difference to the range.
For the receiver module I was working with 5.5V - 6V seemed to give the best range. Anything below 5V was pathetic.
Related
I have bought an HC-12 module, but as much as I have investigated I have not found a way that a Raspberry Pi with a bluetooth detector called bluelog can detect it.
What do I have to do so that HC-12 wired to a Arduino can be detected with the bluetooth scanner?
How to set HC-12 in 'discoverable' mode?
Thank you
HC12 is a 433MHz transceiver. Bluetooth operates at 2.4GHz
What you're trying to do is impossible and doesn't make any sense.
There are other modules like HC05 or HC06 that communicate via Bluetooth. Your HC12 does not. You'll need a second of those transceivers to establish a connection between the Arduino and Raspberry PI.
This will give you up to 1km of range at lower bandwidth while Bluetooth only works across several meters.
So pick whatever suits your requirements best. A HC12 alone won't do much.
Maybe you should spend a few minutes on researching how radio transmission works befor you buy any equipment.
I am working on a project which involves to power on/off a Raspberry Pi with an Arduino. In fact the project contains several sensors like a motion sensor and the Arduino will be supplied with a 10kmA battery.
The motion sensor is connected on the Arduino device.
Once the sensor detects a movement, the Arduino will receive the instruction to deliver the 5V to the Raspberry Pi.
How can I supply the Raspberry Pi with the Arduino? GPIO? USB?
I have already seen solutions to power an Arduino with a Raspberry Pi, but never the opposite.
Powering on is easy: just use a small relay that you control with your Arduino, and which switches the 5v from the battery to the RPi.
Shutting down the Pi should be done in two steps:
Setting a GPIO connection to the GPIO header of the Pi, that "sends" the signal to shut down. The RPi must receive this signal as an interrupt on the GPIO and can execute a shutdown-script
The second step should be to wait until the RPi has completely shut down. Maybe you can observe that with the help of the RPi LEDs or something like that (otherwhise, an unclean solution would be to wait XX seconds). After you know that the Pi is shut down, you can open the 5V relay again.
I have the Arduino UNO board and I want to know if it is possible to use both the USB connection (for exchanging data) and the external jack to power supply it.
I will use the following cable: http://ecx.images-amazon.com/images/I/41OMXaj5cPL.SY355.jpg with a AC-DC 5V adaptor in order to power supply the Arduino. However, I want to use also the USB connection in order to send some data from the computer.
Both will be connected at the same time.
In short, I want the Arduino to be able to run even if the computer is OFF and whenever I open the computer to send data to Arduino from USB connection.
Is this possible? Will the Arduino Uno board support it?
Yes. From the official Arduino website:
Power
The Arduino Uno can be powered via the USB connection or with an external power supply. The power source is selected automatically.
External DC power will override USB power if the Arduino detects it. [Source]
as other said, it is absolutely possible to have both usb and power jack plugged in.
but be aware that if you shut down your computer and turn it on after, when reading the usb port you'll restart the Arduino and might loose important data.
yeah both of them can be used. If you want to upload the code in arduino then simply use the usb cable otherwise keep it on adapter. it wont harm the device.
What I personally do is, I keep on plugging the adapter and remove the usb once I am done with uploading and then test it as normally the usb cable is quite small and I normally work on robots so I need long wires.
if you want just plugs it in, it's ok but Arduino board will chose one and usb has priority to other power source.
********* Very important :*****
if you are controlling other circuits, that are connected to an external power supply, with your Arduino and connecting it to your PC's usb, Arduino will have potential difference and it will cause current flow that will damage your PC and Arduino board. if you want to do such thing, you have to shield your Arduino board from your other circuits that you want to control and they have external power source. this could happen with optocouplers for digital ports, non signal analog ports with shield relays, and complex analog circuits for analog signals
Can run simple programs on Arduino without any elese connected. However the minute I add any sensor (eg gas sensor) or module (eg ENC28J60). the usb serial port on device manger disapears.
Actually anything coonected to Vcc (5 v or 3.3V) and ground of the Arduino Nano Mega 328 causes this problem.
I tried changing borad to Mega 168 etc, but same issue.
A couple of things come to mind:
Ground loops. Using a meter (DVM et al) check for a difference in potential between the ground of the USB bus and the ground of the Arduino. Check both AC and DC settings. You shouldn't see much more than millivolts, but if you do - it needs to be fixed.
If you're using one of those el-cheapo 2-prong wall-wart style power supplies, be aware that a lot of them have some serious ripple on them as they're not generally well filtered. Connecting the (-) negative terminal on the output of those to your USB bus can give you all kinds of fun. And not the kind you'd want. Adding a 0.01uF capacitor between Vcc and ground at the power supply output feed will help with filtering noise.
If the device is powered exclusively by the USB port, know that the 2.0 specification only provides for about 500ma (2.5W). If you have other USB devices hanging off the same bus, your current draw may overload and result in the bus shutting down that port.
Don't mix 3.3VDC components with 5.0VDC components. In other words, if you have a 3.3V bus, attaching the bus or driving something requiring 5.0VDC won't work. You need a converter to go between 3.3V powered devices and those running on 5.0V
Many gas sensors require significant current - it sounds like you're running it off the USB port and I suspect that this is what is causing your crash.
I like to build a project to make my gardening work smarter! My goal is to measure soil temperature, soil water content, light intensity and also taking a picture, and then wirelessly upload these datasets to a webpage. I can also control the irrigation system (turn on/off the pump switch) via the webpage.
These sensors are anagogic! However, the Raspberry Pi Face (PiFace) Digital Interface is only able to take care of digital signals. The PiFace comes with the relaies, which is pretty handy for a startup project. I just like to get some premade boards and ensemble them easily without too work.
Can I layer up a Raspberry Pi board, an Arduino bridge shield, an Arduino board and a PiFace (or a relay board) without wiring?
I really need a recommended "shopping list" to start with. What should I choose?
I suggest you try following the steps outlined in Arduino and the Raspberry Pi.
I agree that you should involve an Arduino as your conduit to the outside world. Then do a simple serial connection between the two. If you get any Arduino except for the new Due, you have got to get from 5 V (Arduino) to 3.3 V (Raspberry Pi). I'd suggest Sparkfun's Logic Level converter.
Sparkfun also has a good light sensor, TEMT6000 Breakout Board.
While you're there, you can grab a couple of thermistors to measure temperature, Thermistor 10K.
Also, Make did an article on almost exactly what you intend on doing (from the Arduino side), Microcontroller-assisted gardening.
On the Raspberry Pi side, Pygame will give you a huge head-start on connecting to the Arduino and taking webcam shots. A Halloween Sound Trigger with Raspberry Pi and Arduino should get you started.
According to what you describe, you may achieve this with only an Arduino UNO, an Ethernet Shield, sensors (at least temperature and light) and a cheap CMOS camera.
If you want to take advantage of the two worlds (Raspberry with Arduino I/O capabilities), you may also consider the Raspberry Pi to Arduino shields connection bridge from Cooking-Hacks: they provide both library and tutorial to start with.