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  1. geezer88

    Ever wonder how long PICAXE projects can last?

    Back in 2011 I build an accelerometer for my home built aircraft. I don't have the plane anymore, but I still have the accelerometer and it still works. It uses an 18M and a two line LCD to implement a digital and analog reading. Calibration is done use good old natural gravity. A single...
  2. geezer88

    SX126x LoRa modules !

    Time for a quick update. The signal strength, RSSI, has been increasing for the last week or so. I think the newly opened leaves and the rain blocked the signal more effectively than when dry. That seems intuitively right, as more water content the blocking effect would be increased. In his...
  3. geezer88

    Be afraid, very afraid !

    Don't forget the non-lethal crowd dispersing robot: Fartius
  4. geezer88

    SX126x LoRa modules !

    Here is a bit of an update. I set my Dorji SX1268 modules BW31.25, SF12, and CR 4/5. With only a few tests, RSSI varies from 142 to 150, about the same as where it has been the last couple of weeks. Besides the leafing out of the oaks, I do see signal levels drop in heavy rain. So far, I...
  5. geezer88

    SX126x LoRa modules !

    Here's my settings: Band width=125khz, Spread factor=11, Code rate=4/5 Each transmission consists of: two byte qualifier and a single byte data. I tried a spread factor of 12, but that didn't seem to work. I may have screwed up in using the setting tool. I went back to 11, and quit...
  6. geezer88

    SX126x LoRa modules !

    The new nine element Yagi is at my house. So far, the mailbox, made of plastic, conceals a two element Yagi, but there is room for one more element. Around here, mailboxes get clouted by kids, so I don't want anything to attract attention to mine. The only exception is the 100mm square solar...
  7. geezer88

    SX126x LoRa modules !

    The oaks have leafed out, and reception between the mail box has been interrupted. Before I build a repeater, I figured I'd spend more time on antennas. The mailbox has a two element Yagi and the house has a Yagi with three elements. They are both from plans found on internet, and have had no...
  8. geezer88

    Choice of Display module.

    You might consider the Nextion display: https://nextion.tech/ It's not cheap, but it gives you both a display and touchscreen input. The device has enough power to take a fair load off the Picaxe and uses a simple uart interface. Advanced models have real time clock and 8 bit gpio. tom
  9. geezer88

    SX126x LoRa modules !

    Yikes! Now I know why mine came with water jacket cooling connections. Taking your numbers from above: 220 is a good signal, 140 barely works. By the formula in the Semtech manual, 220 becomes -110dBm and 140 becomes -70dBm. -70 is bigger than -110. I'm still missing something. Maybe I'm...
  10. geezer88

    SX126x LoRa modules !

    Right. Except in the Semtech manual it says: Average over last packet received of RSSI Actual signal power is –RssiPkt/2 (dBm) Doesn't that minus sign make it a negative number, whose value would get larger as the signal increases? Maybe the Dorji folks do something to it. Anyway, I...
  11. geezer88

    SX126x LoRa modules !

    Thanks for taking the time to respond. "RSSI is a negative value. As signals get weaker it get more negative." That is what I get from reading the manual. But, walking with a receiving Dorji DRF1268 I get raw RSSI numbers that decrease as I walk further from the transmitting unit. In the...
  12. geezer88

    SX126x LoRa modules !

    Thanks for the idea of SNR. I didn't see that as an option on the Dorgi configuration tool, so I didn't search further. I did find it in the semtech manual. I'll have to see how hard it is to enable and use it. As far as the Ebyte 1 watt module is concerned, that was purchased as a backup if...
  13. geezer88

    SX126x LoRa modules !

    After looking at the data sheet in your post, I see I screwed up. The modem I have is an SPI interface, and I thought I was getting a uart version. I guess I will have to figure that out. If someone else has blazed the trail, I would love to see your code. I guess the adage about older and...
  14. geezer88

    SX126x LoRa modules !

    Thanks for the url. I downloaded their manual awhile ago, but it isn't as complete as the one you just showed me. tom
  15. geezer88

    SX126x LoRa modules !

    I have used the Dorji DRF1268DM modules with great success for my mailbox alert. I've been watching the RSSI numbers to see how much the leafing out oak trees will impact the results. I have scoured Semitech's website and documents, but haven't been able to find out just what the "RSSI" signal...
  16. geezer88

    Programmer jack warning

    That is what I did. I oversized the hole in the metal case and used a scrap of lexan to mount the jack. All is well now. Just wish I had remembered the back*ssward polarity. tom
  17. geezer88

    Programmer jack warning

    I searched for this without finding anything, so here's a gotcha on mounting a stereo jack to a conductive chassis. The serial in on the programming cable is wired to the barrel of the plug. On most equipment the barrel is grounded by the jack on a metal chassis. So if you use a metal jack...
  18. geezer88

    Where's the Wizard ?

    I'm with Buzby on this. I'd love to have an app on my smart phone or tablet that I could customize to do stuff with a picaxe system connected by bluetooth or wifi. It would be really neat to instantly see on my phone the status of gates and sensors, or control actuators or other variables. It...
  19. geezer88

    For sale.Cold fusion reactor.Home made.Not working.$2000 ONO

    My last reply was rather snarky. I got to wondering what the real topic was. If I understand it correctly, it boils down to what is volts vs emf? My personal understanding is that volts is the unit of measure, and emf is the driving force behind electron movement. But that is my simple...
  20. geezer88

    For sale.Cold fusion reactor.Home made.Not working.$2000 ONO

    It's okay with me if you offend irritating people. tom
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