Hi Guys,
Just want to give a quick heads-up and something to be aware of re 433Mhz modules. Since building some new WeatheDuino modules recently, I encountered an RF issue that I've been looking into over the last couple of weeks.
The Issue
My production WeatherDuino system has been in operation now for over a year and hasn't missed a beat, literally - it just works. I built up the first Pro2PLUS receiver, set the station ID and proceeded to do some testing with my production transmitter station outside. The RF link was not so solid, with the RX in the same location as the old Pro2 receiver - no environmental / location changes. After creating some new debug code and looking at packet reception, it seems that I was getting a lot of corrupt / unreadable packets being received, among the good ones. The receiver did work somewhat, and I could receive valid data, but I would frequently get "---" readings for the outside Temp and Humidity. If you didn't know any better, you may just say that it was a RF transmission issue. Even with the new Pro2+ receiver outside and within a few meters of the transmitter, I would still see the same results. But as soon as I shutdown and started up the old Pro2 station, all was good again and totally solid RF link.
I had a test Pro2 transmitter station on bread board, and it didn't take long to create a test Pro2 receiver station on breadboard as well. Using these test stations as a set, I was able to test these new 433Mhz modules, and they were totally solid and no corrupt packets when used as a new pair / set. I was even able to take the test TX station outside and get solid link back into my workshop where the test RX station was located. All good when used as a new set (ie. a set of TX and RX modules purchases as a pair from the same seller / manufacturer). But as soon as I mixed my old Pro2 TX station with the new 433Mhz RX modules, I experienced issues again even over short distances of a few meters.
The Modules
The old modules that I bought are no longer available / listed on eBay. The new modules that I bought are still available as a set, and when used as a set they are giving a solid and reliable RF connection / path. Refer URL below:
http://www.ebay.com.au/itm/ASK-AM-RF-Sup...SwdzVXi21n
Summary / Lesson Learnt
I NOT saying that you will have issues if you buy / mix various 433Mhz modules, but my testing seems to indicate that you "may" have issues if you use mixed modules. Differing age of the modules (old vs new) I think may also be a contributing factor and the aging crystals on the old modules may not be as locked on as they were when new. My advice for a new builder would be to buy a set of 433Mhz TX and RX modules as a pair from a single seller/supplier, and keep / use them as a set. If you think that you may want a spare set of modules for later, buy them at the same time so that all modules are matched from the same manufacturer / seller.
I'll keep testing and be sure to update this thread again, when and if more information comes to hand. [edited]
Mark R
Just want to give a quick heads-up and something to be aware of re 433Mhz modules. Since building some new WeatheDuino modules recently, I encountered an RF issue that I've been looking into over the last couple of weeks.
The Issue
My production WeatherDuino system has been in operation now for over a year and hasn't missed a beat, literally - it just works. I built up the first Pro2PLUS receiver, set the station ID and proceeded to do some testing with my production transmitter station outside. The RF link was not so solid, with the RX in the same location as the old Pro2 receiver - no environmental / location changes. After creating some new debug code and looking at packet reception, it seems that I was getting a lot of corrupt / unreadable packets being received, among the good ones. The receiver did work somewhat, and I could receive valid data, but I would frequently get "---" readings for the outside Temp and Humidity. If you didn't know any better, you may just say that it was a RF transmission issue. Even with the new Pro2+ receiver outside and within a few meters of the transmitter, I would still see the same results. But as soon as I shutdown and started up the old Pro2 station, all was good again and totally solid RF link.
I had a test Pro2 transmitter station on bread board, and it didn't take long to create a test Pro2 receiver station on breadboard as well. Using these test stations as a set, I was able to test these new 433Mhz modules, and they were totally solid and no corrupt packets when used as a new pair / set. I was even able to take the test TX station outside and get solid link back into my workshop where the test RX station was located. All good when used as a new set (ie. a set of TX and RX modules purchases as a pair from the same seller / manufacturer). But as soon as I mixed my old Pro2 TX station with the new 433Mhz RX modules, I experienced issues again even over short distances of a few meters.
The Modules
The old modules that I bought are no longer available / listed on eBay. The new modules that I bought are still available as a set, and when used as a set they are giving a solid and reliable RF connection / path. Refer URL below:
http://www.ebay.com.au/itm/ASK-AM-RF-Sup...SwdzVXi21n
Summary / Lesson Learnt
I NOT saying that you will have issues if you buy / mix various 433Mhz modules, but my testing seems to indicate that you "may" have issues if you use mixed modules. Differing age of the modules (old vs new) I think may also be a contributing factor and the aging crystals on the old modules may not be as locked on as they were when new. My advice for a new builder would be to buy a set of 433Mhz TX and RX modules as a pair from a single seller/supplier, and keep / use them as a set. If you think that you may want a spare set of modules for later, buy them at the same time so that all modules are matched from the same manufacturer / seller.
I'll keep testing and be sure to update this thread again, when and if more information comes to hand. [edited]
Mark R
