-
its normal. it has to do with temperature and ground hydrological pressure and other things. they are not consistent I noticed quite a large variation.
Not sure what you are referring to - can you elaborate ?
-
What chip is the usbttl? When you scoped it, did you leave a trigger on it for the whole 24hours? The only thing that comes to mind is that it's sending something very infrequently (like every 24hrs). Can't imagine why... especially in the case where you didn't plugin the usb data pins.
Quite strange. -
What chip is the usbttl?
https://auseparts.com.au/FT232RL-3.3V-5.5V-FTDI-USB-to-TTL-Serial-Adapter-ModuleWhen you scoped it, did you leave a trigger on it for the whole 24hours? The only thing that comes to mind is that it's sending something very infrequently (like every 24hrs). Can't imagine why... especially in the case where you didn't plugin the usb data pins.
Quite strange.
No, as I had nothing to trigger on - I did free-run at .2s/div at humspeed and at 4800baud speed - after that I scanned through all the speeds.
Why would a once/24h trigger affect the whole day of operation. I would expect triggers within each hour ?! -
radon levels might average in a year. seasonal dependence too
-
OK, I wrapped it up in a proper box and my Radon-device is now sending Syslog messages every 15min - I will probably change the interval to 30 or 60 minutes as the meter only changes once per hour
I added rechargeable battery and some logic to monitor battery level. Now the syslog looks likeCode: [Select]2024-01-28 18:15:05.001 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (1-0) [80 10 12 11 82 1e 0d 03 6d 00 00 50 00 00 80 a5] 1-day=56, 7-day=59, longterm=59, uptime=4:03:13:30, volt=4180 / USB
2024-01-28 18:30:01.967 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (2-4) [80 10 12 11 82 1b 1c 03 6d 00 00 50 00 00 80 a5] 1-day=56, 7-day=59, longterm=59, uptime=4:03:28:27, volt=4196 / USB
2024-01-28 18:44:59.585 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (3-4) [80 10 12 11 82 19 2b 03 6d 00 00 50 00 00 80 a5] 1-day=56, 7-day=59, longterm=59, uptime=4:03:43:25, volt=4176 / USB
2024-01-28 18:59:57.865 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (4-4) [80 10 12 11 82 17 3a 03 6d 00 00 50 00 00 80 a5] 1-day=56, 7-day=59, longterm=59, uptime=4:03:58:23, volt=4178 / USB
2024-01-28 19:14:57.956 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (5-4) [80 10 12 11 82 17 0d 04 6d 00 00 50 00 00 80 a5] 1-day=55, 7-day=59, longterm=59, uptime=4:04:13:23, volt=4172 / BAT
2024-01-28 19:29:56.999 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (6-4) [80 10 12 11 82 16 1c 04 6d 00 00 50 00 00 80 a5] 1-day=55, 7-day=59, longterm=59, uptime=4:04:28:22, volt=4174 / BAT
2024-01-28 19:44:55.638 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (7-4) [80 10 12 11 82 15 2b 04 6d 00 00 50 00 00 80 a5] 1-day=55, 7-day=59, longterm=59, uptime=4:04:43:21, volt=4156 / BAT
2024-01-28 19:59:53.597 +01:00 10.7.14.152:4444 local0.info [] RADONESP32: (8-4) [80 10 12 11 82 13 3a 04 6d 00 00 50 00 00 80 a5] 1-day=55, 7-day=59, longterm=59, uptime=4:04:58:19, volt=4168 / BAT
-
Just wanted to thank you all for your work on this project. I picked up a unit on eBay because it was cheap, and searched the model name + "hack" because I wanted better access to data, and this is pretty much the best kind of result one could hope to find from that. I'm just too early, I guess! Good luck.
Stupid question, but has anyone considered bypassing the computer and trying to read off the sensor directly? -
Thanks, I'm happy you can use it.
The TTL 3.3V port in the Airthings device is very picky and even small leak currents in TX/RX makes the device stop counting and hence deliver to low numbers.
As you can see above my readings dropped to 0 whan I had a computer connected via a USB2TTL33 converter.
We never found out exactly what happened, but I found that the ESP32 serial port was "accepted" by the device and as I wanted to build a standalone WiFi device I followed that route.
My implementation has the serial port on ESP32 live/active approx. 20s 4 times an hour, and that may be why it does not affect the device.
PS: My battery lasts > 2months on one charge. If I only polled the device 2 or 1 times an hour the "lifespan" could probably be much longer. The device is only updated internally every minute, so polling once a minute should be fine.
-
Personally, I've lost interest in this and moved on to the next project. Glad it helped those that took interest.
bypassing the computer and trying to read off the sensor directly?
The sensor measurement had some concept of counting pulses (radioactive decay events?) on a GPIO pin. I suppose you could sample that signal directly, but without reversing the full firmware algorithm and calibration scheme, we don't know how to translate it into a meaningful metric. -
Fantastic work, this is exactly what I was looking for my radon meter.
I will post the code when I got it a little cleaned up.
Seems like it never got cleaned up
I wouldn't mind getting the code even if it's not cleaned up.
-
Thanks for the positive feedback - it's nice that someone can use the work we did.
I have attached the code I have been running for 8 month now - could be cleaned up - but it works :-)
Please update the thread if you find errors or have improvements...!
I used PlatformIO as development platform, but any platform including AduinoIDE will do.
Claus
-
Finalized my take on this and got the code into a Trigboard with some small modifications.
Got it nice and tidy by modeling and printing a box housing the Trigboard which snaps in place of instead of the battery lid.
The Trigboard is configured to read every 4h and uses the power from the same battery source as the sensor.
Once again many thanks for all the job done on this!
-
Incredible work reverse engineering this!
I stumbled on your work today while looking for a solution to an efficiency problem...
===
Background:
I recently installed an ERV in my crawlspace to reduce some numbers that were much too high. Thankfully, it appears to be working! Now I would like to make it efficient, only moving air when radon levels are high.
Dream:
I would like to be able to pull data from my Airthings Corentium, run the output through an ESP32 to trigger the ERV to reduce power or stop altogether, depending on the Airthings readings.
Other solutions:
Until I found your solution, the only other answer I could find was the $750 Radonova Robin (standalone Radon detector) whose output signal -- no screen, just a 1-10v output depending on Radon reading -- that can be translated to a motor control.
===
I would really like to try to build what you have made, but I could use a wiring diagram for your breadboard. Would you be willing to draw one up and share it -- even if its on the back of a napkin!
Thanks!
-
Sorry I did not see your comment until now.
Thanks for kind words !
I have some notes somewhere, but a quick look did not reveal something.
For now I do not have time to dig deeper, but if I find them I will post them.
The code shows all pins used on the ESP32.
The Veroboard is only to have a solid base for the additional components for the battery management and RS232 to the Airthings Radon Device.
The trick is to solder only needed pins from ESP32 module to Veroboard allowing some pins on the non-battery side to be available on the component stripe near the battery without cutting the Veroboard
There is one extra circuitry is the two 1M+1M resistors that divide the battery voltage into half allowing me to measure it on a 3.3V analog input.
There is also a 1M resistor between 5V next pin GPIO13 which allow the code to determine if the ESP32 is being fed from USB and hence is charging.
On the the right side away from the battery the TX0, RX0 and second GND from top has a (high) pin to allow debugging of the ESP32 while running. Please not these three pins does not connect to the Veroboard.
Be careful with the Lithium cell - if you short it or physically beat it it may blow up in fire.
EDIT----
I found one of my notes showing which ESP32 pins are connected to the veroboard (marked with a big dot).
On the right is the list of signals available on the Veroboard.
I don't remember why I connected EN to Veroboard it does not seem to be connected to anything.