Decoding RF signal from Ambient Weather Thermo-Hygrometer

Excellent work.
Can you share the rest of your code?
Cheers Rob

Would be glad to if you can point me to an easy way of posting the code somewhere. It exceeds the 9K character limit of a post for posting it inline and I haven't tackled using git (I'm still back on Subversion).

Also, is there a way of monitoring a thread? I've marked my replies with "Notify me of replies" but I'm not getting email notifications.

Per robwlakes request, <update: link removed, code is attached in my next reply) It is based on the excellent work of others on the Manchester decoding found in the F007th sketches. Apologies for the changes for style - it is simply personal preference. I also modified it to use arrays rather than 7 scalars. And removed the Wifi and Xively code I wasn't using. I plan to soon combine it with the webserver example via the exec library and serve the sensor values via my Ethernet shield.

Hi, use the Attachments and other options, to attach your sketch.

Tom..... :slight_smile:

Thanks for the pointer. Duh!
Here is the full code attached.

Temperature.ino (11.2 KB)

That is looking very good. Very compact, effective coding. Nicely done.

Glad to be of assistance,

Rob

The Ambient F007TH Sensor appears to be the same as the (Australia & NZ) Jaycar XC-0328 kit and the Jaycar XC0329 individual sensor. I just noticed today that they have put both of these on clearance, so this connection is only likely to be of use to those who already have one.

I have been trying to understand the basic parts of the code. I would like to use a NodeMCU ESP8266 or WEMOS equivalent to replace the CC3000 in the existing code.

If I understand correctly, one of the key lines is:

pinMode(RxPin, INPUT);

I can see that "int RxPin = 8; //The number of signal from the Rx"

I don't understand what this corresponds to. Is it the number of potential sensors? Is it the input on the CC3000?

Using a RXB6 receiver module I was able to decode 433MHz codes from a 433MHz RF switch.
The code used for that used
"mySwitch.enableReceive(13); // Receiver on interrupt GPio 13 => that is pin D7"

Would the line become?:
pinMode.enableReceive(13);

Any assistance would be very much appreciated.

pinMode(RxPin, INPUT);

I can see that "int RxPin = 8; //The number of signal from the Rx"

I don't understand what this corresponds to.

Arduino pin 8 is used in this case as an input to read the data output by the receiver. Any cheap 433 MHz receiver should work with the code in reply #33 above.

int RxPin = 8;

means that instead of using the character/number "8" to represent the number of the pin in question, the label "RxPin" can be used instead. Change 8 to another number in that line and that number will be used by the rest of the program wherever RxPin is used. The comment added after the // is quite unhelpful. As jremington suggests the 433MhzRx's output is attached to pin 8 which is the input in this case.

Using a RXB6 receiver module I was able to decode 433MHz codes from a 433MHz RF switch.
The code used for that used
"mySwitch.enableReceive(13); // Receiver on interrupt GPio 13 => that is pin D7"

Would the line become?:
pinMode.enableReceive(13);

This is more confusing to me. mySwitch.enableReceive(13); would be some sort of procedure call either in another part of the same program or a library call. If it is an Arduino it sounds some what unusual as I am not aware that 13 is the interrupt pin on an Arduino. Usually people just make use of Pin13 as an output with a status LED on it.

pinMode() sets the operation of a given pin as either an input or as an output, and should not be considered interchangeable with mySwitch (most likely a library call?).

If you have code working with CC3000 it is unlikely you can swap a NodeMCU ESP8266 or WEMOS in and not adjust your code to the new hardware. Most likely you will need appropriate libraries for the new hard ware and then have to adapt the main program to use the new hardware library.

I hope this helps, R

Thank you both for such helpful and prompt responses.

Looks like I will need to do more research on this topic, but at least I appear to have found working code and a well known name and model number of these sensors.

I wonder if Ambient is going to discontinue these sensors or it is just a decision taken by the local importer/distributor Jaycar?

I had to swap from a "Bios" weather station setup using a USB interface, to my current one with Oregon Scientific + Arduino->USB and it works so much better. I bought a second OS Anemometer as a backup, as that was what broke on the Bios (I had bought 2 Bios systems when they were no longer sold, so third time unlucky). However the swap to the OS+Arduino solution is so much better, forced me to move on. I also have a 3-D printer now so could probably print repairs eg broken cups. :slight_smile:

Good luck...

Just remember to scan the cups before they are broken. If it is broken in a storm, you might not have all the bits to work with.

robwlakes:
int RxPin = 8;

means that instead of using the character/number "8" to represent the number of the pin in question, the label "RxPin" can be used instead. Change 8 to another number in that line and that number will be used by the rest of the program wherever RxPin is used. The comment added after the // is quite unhelpful. As jremington suggests the 433MhzRx's output is attached to pin 8 which is the input in this case.

Thanks for the help again.

I now have the WEMOS D1 Mini reading the data correctly and outputting the serial monitor.
Here are the changes I made to the code to get it to work.

// Libraries
// #include <SPI.h> Not needed as this is already included for ESP8266

#define MAX_BYTES 7
#define countof(x) (sizeof(x)/sizeof(x[0]))
// Interface Definitions
int RxPin           = 13;   // Receiver on interrupt GPIO 13 => that is pin D7

robwlakes:
GitHub - robwlakes/ArduinoWeatherOS: Arduino Uno, 433MhzRx and OS WMR86 Weather Station

Cheers, Rob

Rob I was having a look at your Github page, very impressive work. I didn't think a Github page could look that good. In the circuit diagram I noticed that you have the ground next to the antenna connection on the 433MHz receiver going to the ground on the Arduino Uno. If I understand correctly, this is not the correct way to do it. This particular ground is the ground plane for the antenna. Now depending on the physical design of your system and where the antenna is located, the way you have it may actually degrade the reception sensitivity of your system. If it is working fine, then don't worry.

I have been amazed at the range I have been obtaining with the RXB6. I just have it on a breadboard without an antenna and it is picking up the signal at the other end of the house. Never expected that.

Yep, I agree with what you are saying, I now use a bit of coax with the shield stripped back and the core as an antenna. So the shield goes to the earth nearest the ANT and the core to the ANT connection. I have found it works really well.

I have added an indicator light as well as incorporating a UV detector and original sensor in to the design as well. i am pleased you are getting value from this project.

What a great project!

I am really interested because I have built a multi zone heating controller using a Raspberry Pi, but now it needs some wireless thermostats, well, thermometers. I considered porting this code to run on a PIC which would be connected to the Pi using I2C but then I thought that it would be quicker to use an Arduino, but I know NOTHING about them.

Could someone give me some Arduino hints, please.

EG Would a 'Arduino Nano v3.0 – Compatible Board CH340G 5V 16MHz atmega328 Tested' be compatible?
Could I connect it to a PC using USB and no fancy hardware programmer, and then modify the code to send the data to the Pi over I2C or bit-bang it out - using a free development environment?

This is a non-commercial hack so as cheap as possible, please.
I have a homebrew PIC programmer and free C development environment so it would only cost 2.40GBP/3.20USD for a PIC12F1822 if I went that route. (I also have vero board etc lying around)
But I'm sure you want to persuade me to go Arduino, don't you? (where's the smiley face button?)
Sorry to those that get offended at the mention of such 'other' devices!

Well it is up to you of course. As a PIC user from wayback, there is no way I would return those processors with what the Arduino ecosystem offers now.

I have used the Oregon Scientific (Chinese BTW) sensors and think they are quite good quality for the money. My GIT-Hub pages outline two types of project. One is to build an Arduino Uno base station that intercepts OS sensor signals and allows you complete freedom to build your own system from there on. The main trick provided in the code is how to intercept the 433MHz signals and decode them. My strategy was to turn these signals into a string and simply send a serial message across the Arduino's USB/Serial connection back to the main computer (it is now a RPi3, but was an Intel Atom previously). Again this string can be interpreted by Python programs and processed to your hearts content.

433Mhz interceptor: GitHub - robwlakes/ArduinoWeatherOS: Arduino Uno, 433MhzRx and OS WMR86 Weather Station

It also has a good run down on Manchester protocol, which many weather stations use in one way or another, if you wanted to try to roll your own Arduino or PIC version.

The second project involves making your own sensors that can integrate into the OS system without too much hacking. In essence it is designing your own OS sensor (I have one one monitoring solar energy at the moment, and previously had one monitoring lightning strikes). All I had to do was extend the code for the list in the Interceptor to detect the new sensors, and add that to the exported string.

Roll your own OS: GitHub - robwlakes/Weather-Station-OS-Sensors: Weather Sensors, Tx & Rx for Arduino plus 433MHz

Note it easy to create a wireless Temperature sensor from Arduino bits and (as shown in the example given) much cheaper as well, if you have the bits lying around. However it is much harder to replace the OS temperature sensor where low power consumption and long battery life is important. The OS sensors are very battery efficient and getting a home built sensor into this range is certainly a higher level of difficulty.

The Solar Power sensor I made is based on an Arduino Mini-Pro (the only low power alteration is the power LED has been removed) and it survives long term as it uses a solar panel (and why not? :wink: ) to charge a LiPo battery. If your sensor points are near permanent power, then this will not be a worry.

Get some Arduino Mini-Pro boards, some 433MHz Tx boards and some DS18S20 for the sensors, and an Arduino Uno and 433MHz Rx for the base station and get into it.

The Arduino system does not need a dedicated programmer board, usually just a stock USB cable. And you get the IDE free with a multitude of very handy libraries.

Cheers, Rob

Thanks Rob for your detailed reply.

I already have a couple of F007TH sensors and a Pi Zero ready to ask for thermometer data over 5v I2C, so a simple arduino setup to receive the signal, decode it and await the Pi's request is all I need.

A Uno is rather large for an embedded component so I've gone for a Nano clone. I nearly bought a pro micro as its cheaper and smaller but then realised that it makes it difficult to use I2C (apparently D4 and D5 aren't exposed) and also I would need to buy an additional programmer for it as it doesn't have a USB connection.

I currently have a PC connected by USB to a Nano 3 clone CH340 (with the right driver!) connected by D8 to a 433mhz receiver. I have downloaded BaronVonSchnowzer's Temperature.ino and immediately got it working as it sends output to the USB serial device which I can view using serial monitor in the IDE.

I would like to create an I2C slave device but it may not work very well as the RF receive code is timer based. So is there a good reason for it not being interrupt driven? Is it just that state machines are scary? There is already Arduino code out there to do IR receive which uses interrupts, maybe I could adapt that.

PS I've got surprisingly good range having only attached a 17.3cm length of wire to the receiver board. I was considering making a dipole but I won't need to.

Hi AG,
I like your style!! Progress already. I got onto some clone Arduino Pro-Mini versions that are a good size and also have the 4 and 5 exposed in a double strip across the bottom.

The only drawback is that I have to press the reset (at the right time) to get it to download, just after a compile. However they are compact, and with the extra pins quite versatile. There are many Pro-Mini boards on sale, but not all are like this one.

I haven't tried to create an I2C (or SPI) device, so I can't help you there. However I have hooked up my Temp transmitter board to the parent Arduino, and removed the 433MHz Tx and RX boards all together and it worked fine, very reliable using the Manchester code. I did that just to debug the Tx code without blasting the 'real' Rx in the shed with test signals.

The use of interrupts would be good. I only ended up using a 1 minute "report to RPi3" interval as my old BIOS weather station had all readings combined and sent them once every minute. My Python code was set up to use it as the time base, so I fashioned the later Oregon Scientific sensor software to replicate the same thing. My whole Arduino to RPi3 system is centered on the weather sensors so it does not matter if they dominate the situation (plus the weather data for most sensors is only graphed for 12 hours and so the accumulated errors of using the Arduino time base is fairly small over that 12 hours). Daily long term samples (eg rainfall) are triggered from the clock on the RPI3 which is synced with NNTP. My Arduino base station just reuses the last reading if a new one has not turned up in the last minute. eg anemometer reports every 14 seconds, so rarely (see below though) misses, however UV is 75 seconds cycle but still acceptable for my purposes.

SPI would be good, and does not insist on interrupts? I think I would prefer SPI, it does not appear as mysterious as I2C. RPI has good SPI facilities. You can choose ;-). I have used the IR receive interrupt circuits (I designed an advert killer that mutes the TV when the cable adverts come on for 2, 2:30,3:00,3:30 minutes by pressing the Red, Green,Yellow or Blue buttons respectively on the Sony remote. So it does both, Rx from the human+remote, then translates that to Tx to mute function. Press the coloured button and it mutes, but comes back on auto-magically :slight_smile: eg when still making coffee!!)

The flexible antenna is good. I suspect the rigid helical antennas inside the Oregon Scientific sensors are too rigid and in the extremes of the weather, crack the solder or PCB and become intermittent. Flexible is better I reckon. Though harder to sell to the masses, not quite so tidy!! I have fixed my UV sensor this way. My anemometer has recently been intermittent so I bought new Lithiums yesterday to replace the batteries. When I got them down from the roof and tested them, they were very highly charged, so I am suspecting another 17.3cm "whip" antenna coming up very shortly!!! (so to speak).

Cheers, Rob

This is very cool. I have two F007TH sensors and four F007TP sensors used for refrigerators/freezers. This is my first Arduino project as I've been wanting to get history data from my Ambient system forever! I purchased an Arduino Uno kit (overkill for this) from Amazon along with a 080408 433 mHz receiver and was able to start getting data almost immediately. I had to tweak the code a little for my use. I found that the F007TP sensors have a different ID (datatype 0x46). I was able to modify the Arduino code that Rob posted to basically force the humidity values for the F007TP sensors to 0. I also added a variable in the setup to set the units for Fahrenheit or Celsius changed the units to F. I created some variables at the start to rename my sensors rather than changing the hard coding throughout the sketch.

I haven't completed my project yet, but I'm very close. I still want to use the Battery Bit for notification of a low battery since I don't go into my basement very often and that would be helpful. This isn't done along with the WIFI data collection piece.

Many thanks especially to BaronVonSchnowzer for his work on reverse engineering the data stream!
Greg