- Netduino Forums
- → Scott Green's Content
Scott Green's Content
There have been 34 items by Scott Green (Search limited from 18-May 23)
#17142 Netduino+ WeatherStation / Environment Monitor / Webserver
Posted by Scott Green on 27 August 2011 - 01:58 AM in Project Showcase
#17131 Error Deploying Solution
Posted by Scott Green on 26 August 2011 - 09:34 PM in Netduino Plus 2 (and Netduino Plus 1)
#17129 Error Deploying Solution
Posted by Scott Green on 26 August 2011 - 09:18 PM in Netduino Plus 2 (and Netduino Plus 1)
#16723 OneWire ALPHA
Posted by Scott Green on 14 August 2011 - 11:57 PM in Beta Firmware and Drivers
Not entirely sure I understand your question, so I'll try to answer with some observations/facts.
- You must have this native driver to directly communicate with 1-wire devices (parasitic or not) with the Netduino (alternatively, you can use components like those from Peter Anderson)
- With this firmware, I can read from a mix of DS18B20, DS18S20, DS18B20PAR sensors some connected in parasitic mode (only 2 wires - ground and 1-wire signal) and others connected with the 5VDC (non-parasitic). I currently have 5 sensors connected - 3 are not parasitic and 2 are parasitic. That works fine.
- On occassion, I will get a bad read (think 1 in 50 reads) for whatever reason (possibly because I don't have a MOSFET as recommended), but with the CRC check, you always know, so I handle them easily. And usually, it won't happen twice on the same sensor.
-Valkyrie-MT
Valkyrie,
Can you elaborate on the CRC fix you are using to deal with the bad reads? I am getting some bogus temp readings as well..
Scott...
#16702 OneWire ALPHA
Posted by Scott Green on 14 August 2011 - 06:04 AM in Beta Firmware and Drivers
FANTASTIC! The One-Wire code in the firmware appears solid to me. I haven't seen any issues with it. Although, I really wanted to see a much simpler and object oriented way of working with 1 wire, so I wrote a wrapper class (called OneWireNetwork) out of CW2's sample. I only tested it with my DS18B20 sensors, but I have more coming soon and hopefully will add classes for them. So, what I did was create a collection class of devices that has a "Discover" method to scan the One-Wire network for devices. I hope this can be the start of a One-Wire framework that will make this the easiest One-Wire platform available. I have attached the code to this post. It is a complete replacement for CW2's OneWireTestApp project from the first post. Also, this example works with 1, 2, 3, or more devices, using parasite power or not.
By using the library, the code gets very simple:
public static void Main() { // TODO: Change pin according to the actual wiring var deviceNetwork = new OneWireNetwork(Pins.GPIO_PIN_D0); // Interrogate the devices on the network (adding them to the collection) deviceNetwork.Discover(); while (true) { // Loop through all the discovered devices foreach (var aDevice in deviceNetwork) { Debug.Print("Address: " + aDevice.Address); if (aDevice is DS18B20) Debug.Print("Temp: " + (aDevice as DS18B20).Temperature); } Thread.Sleep(20000); } }
Output:
1-Wire device present Multiple devices present 72000002DC320128 B2000002DC405128 54000002DC577D28 Address: 000002DC3201 Temp: 23.375 Address: 000002DC4051 Temp: 23.4375 Address: 000002DC577D Temp: 23.5 The program '[16] Micro Framework application: Managed' has exited with code 0 (0x0).
Things still to add:
Support for reading and writing to the device memory
Throw Events for device alerts
Robust exception handling
Throw Events for devices being added or removed
Support for a variety of One-Wire devices
Automatic instantiation of classes based on detected device family (should probably use some Reflection here)
I think CW2's firmware should get included into the next Beta. Let's get more people trying to use it...
*** Thanks again to CW2 ***
-Valkyrie-MT
Valkyrie,
I noticed that ever time you call Discover() it causes "foreach (var aDevice in gdeviceNetwork)" to add a new device to gDeviceNetwork...
May be intended, but if you put the discover in a loop, it adds a new device for every 1wire device you have on the network each time you call it. Seems like you should put a CRC check to make sure that the same device is not being added for each call...
FYI: I moved the Discover() call outside the loop, once at the top of Main() and it solved my problem..
Scott...
#16695 OneWire ALPHA
Posted by Scott Green on 13 August 2011 - 07:38 PM in Beta Firmware and Drivers
IMHO the problem is that your oneWire object uses pin D0 that also has alternative function of being RxD of COM1 and it tries to reserve it during its initialization, which results in exception. To resolve the issue, you can use different pin for OneWire, e.g. D2, or switch to COM2 (D2, D3) for serial communication.
CW2, That did it! Thanks!
Scott...
#16689 OneWire ALPHA
Posted by Scott Green on 13 August 2011 - 05:49 PM in Beta Firmware and Drivers
#16603 OneWire ALPHA
Posted by Scott Green on 11 August 2011 - 03:35 AM in Beta Firmware and Drivers
#16599 Netduino Plus Firmware v4.2.0 RC1
Posted by Scott Green on 11 August 2011 - 02:24 AM in Beta Firmware and Drivers
- Netduino Forums
- → Scott Green's Content
- Privacy Policy