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by ksangeelee
Thu Feb 20, 2014 9:12 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I suspect the issue I may not have the correct data pins connected. I am running a Rev 2 board, but I think the code is for a Rev 1 board and I need to figure out how to translate. So, it could be receiving, but my connection isn't getting the data. Does that sound correct? Yes, that sounds likely ...
by ksangeelee
Thu Feb 20, 2014 8:08 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

What is the recommended procedure for determining the settings? I would bring the transmitter and my receiver close together, to reduce the dependence on having very specific parameters. Once you get a reading, then work back from there - as you increase the distance, the parameters will need to ch...
by ksangeelee
Thu Feb 20, 2014 11:51 am
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

Glad it's working - with hindsight, that even spread of data was a big clue that the pin being sampling wasn't related to the RF signal.
by ksangeelee
Sat Feb 15, 2014 6:40 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I'm not sure how to confirm it's a 433 module. While I don't recall any markings on the module to indicate its band, the packaging from the vendor labels it as 433 FSK in the SMD package. I'd trust the vendor packaging. As far as I can tell, from the Si4320 datasheet (which I think the RFM01 is bas...
by ksangeelee
Sat Feb 15, 2014 5:34 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

The RSSI number is the digital RSSI flag from the status word, sampled every 100us for 250ms, and returned as a percentage of time the flag was set. It updates every 500ms. You can change the duration and interval at line ~310 the 'sample_rssi()' function. I'd expect anything transmitting at 433MHz ...
by ksangeelee
Fri Feb 14, 2014 5:12 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

Hi, It looks like it's picking up a lot of noise. I've noticed what seems to be auto-gain in one or more of the amplifier circuits on the chip, and it might just be homing in on this noise. The first thing I'd try would be to cut and strip back 17cm of your coax core and use that alone as an antenna...
by ksangeelee
Mon Apr 08, 2013 4:08 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

Pi2D2 wrote:
KarlS wrote:Just noticed also that the Station Id is now 0000. It was 0A54 before - another thing set to default.
Looks like you're just getting a bunch of zeros decoded into your receive buffer. Are you checking CRC before calculating your values?
by ksangeelee
Sun Apr 07, 2013 7:07 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

If its still losing it, I will try the coax approach. One other thing I did was to shield the RFM01 module from a very noisy switching PSU in the enclosure - I put some aluminium-foil flat in a freezer bag and wrapped it around the RF module - this improved things enough to get a reasonable signal ...
by ksangeelee
Sun Apr 07, 2013 6:55 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I've not really got my head round what the pulse stats mean yet so any interpretations of what it means would be useful. Pulse stats are just the minimum and maximum values (in microseconds) of the low and high pulses. The signal is a clock of 1ms with pulses of either 500us or 1500us on either sid...
by ksangeelee
Sun Apr 07, 2013 9:19 am
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

The flat lines in my graphs show a lost signal - changing the parameters yesterday gave a lost signal all night! http://dde.poweredbyclear.com/cgi-bin/graphs.cgi?View=-1&Graph=1357930226.9731&Start=end+-+72+hours&End=now&Mode=view&Shift=&Count= Interesting that it seems to happen with falling tempe...
by ksangeelee
Sat Mar 30, 2013 10:18 am
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I the end I switch back tocode from susa side but there are also problems with the connection. After 12 hours the pi get only: ...Pulse stats: Hi: 143 - 988 Lo: 1005 - 1222 (42 point) Pulse stats: Hi: 157 - 993 Lo: 1013 - 1238 (53 point) Pulse stats: Hi: 294 - 997 Lo: 1010 - 1214 (51 point) .Pulse ...
by ksangeelee
Tue Mar 26, 2013 12:17 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

With PCE-FWS20 I only found an initialization problem with the code of Kevin . His code was not working but after lunching the KarlS code it was working. So mixed up the 2 initializations and now it works. Well hacked! Karl's unit, I think, generates a 915MHz FSK signal, whereas mine generates a 43...
by ksangeelee
Fri Mar 08, 2013 10:28 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RFM01-868 noconnection
Replies: 11
Views: 6500

Re: RFM01-868 noconnection

Hi, Try LNA_14,RSSI_103, or LNA_20,RSSI_103 - looks like you're getting some data from the unit, but just not reliably. Finding the 'sweet spot' for your environment has been discussed here - http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=14777, and also in the blog comments in http://www.su...
by ksangeelee
Wed Mar 06, 2013 1:58 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

Ahh right, that should have been obvious :oops: Well, it had me too for a bit :) However, the reason why I'm asking is that my measurements are about 0.5 hPa off from those of a nearby (2km) professional weather station. And as Wikipedia (where would I be without it?) says: “Temperature and humidit...
by ksangeelee
Wed Mar 06, 2013 10:01 am
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

The BMP085 arrived and I have it working using Kevin's bmp085.c program. To calculate the true pressure the program uses the (indoor) temperature measured by the BMP085. Wouldn't it be better to use the outside temperature as measured by the weather station? As I recall, the temperature is used to ...
by ksangeelee
Wed Feb 06, 2013 9:30 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

avago wrote:SCK should be changing state for every transition of SDI
There's a mode of operation (see Si4021 datasheet, page 20) that uses SDI to receive data for transmission (breaking SPI conventions). In this case, SCK must not transition while data is being sent on SDI.
by ksangeelee
Tue Feb 05, 2013 10:43 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

OK, the FSK line did pulse with DMM, but when I put the soundcard OSC on it that's all it was, a simple pulse. The SDI line does carry a data burst with each transmit... The SDI data could just be the 0xC0nn command to wake up the transmitter. If SCK is low during the SDI data burst, then SDI conta...
by ksangeelee
Mon Feb 04, 2013 6:11 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

Pin 16 goes straight to the MCU 'blob' - give me a week or two to get Panalyzer running! :lol: Straight to, or via a PCB pad and a solder bridge? I can't quite make out some of the tracks in the photo. Since you've some doubts as to whether your kit is working properly, you might want to try the vo...
by ksangeelee
Mon Feb 04, 2013 1:16 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

The RF chip is labelled Si4021 Hi Mark, can you find out what pin 16 on the Si4021 connects to? The 4 x 2 pins don't seem to correspond to an RFM02 pinout (e.g. SDI and SCK aren't in the same column). My guess is that FSK goes via the header, down to the MCU, and that this pin will be used to gener...
by ksangeelee
Sun Feb 03, 2013 10:03 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I'm sure I need to do a bit more tweaking....I'm not consistently reading transmitted data (many minutes between successful data received), and also have quite a few crc fails.... ... The other problem is that my frequently Pi freezes while trying to receive data (and the LED is on)...any ideas? We...
by ksangeelee
Sat Feb 02, 2013 2:25 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

ksangeelee wrote:I think bits would need to be right-shifted into the FIFO so they don't end up in the wrong order.
@KarlS, I'm now sure that's wrong - I'd misunderstood part of the transmitter's datasheet. I agree, overflows would be left-shifted. Did you get to the bottom of that bit-shift issue?
by ksangeelee
Thu Jan 31, 2013 10:19 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

1) FIFO overflow by the time you reach the FIFO byte (is 1MHz fast enough to get the byte before the next bit is shifted in?) Shouldn't I see a left-shift than? I think bits would need to be right-shifted into the FIFO so they don't end up in the wrong order. 2) the bit-rate - maybe it's quantizing...
by ksangeelee
Thu Jan 31, 2013 8:32 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I haven't figured out the wind speed and direction yet (the bearing was S -> SE, speed 2->5kmh) and of course no rain data. The rain bucket isn't even connected between November and March ;) Does anyone have a suggestion about the (possible) bit shift? Just some immediate thoughts... The two things...
by ksangeelee
Wed Jan 30, 2013 6:16 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I'm just doing 3 x 8 bytes at 5MHz. I say limited as I'm now getting more bit errors, so it sounds very much like a SPI issue. Do the bit errors also happen in the first two bytes? I ask because it crossed my mind that the 2.5MHz limit, stated in the datasheet, is because of hardware limitations of...
by ksangeelee
Wed Jan 30, 2013 6:01 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 193
Views: 73843

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

The 6 offset bits returned by the status command are either all 0 or all 1, so this won't help at the moment to determine the correct tx frequency. All 1's could indicate that the deviation is more than -120kHz (e.g. -16 * 7.5kHz), so knocking around 240kHz off the centre frequency at a time (via F...

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