DTH22 digital verification With a logical analyer

[ceramicCAP]

I am looking to have a better understanding of digital signals.
I am going through some of my digital sensor modules and i am getting them to post to Arduino nano then to computer. I think my process has something to be desired. I am trying to find a quick way to decode a digital wave form into a digital number. I am getting that the device is a nonstandard protocol but i don’t normally verify a lot of digital components. Right now the DTH22 is being controlled by the nano, but i would like to make some custom waveforms with analog discover2 to control DTH22 and to read to the DTH22. As well i would like to feed in false data to the nano and receive false data from the nano.

Note this required a 10k ohm (pull up resistor) between signal and VCC(5v)

|17:03:22.834 → Humidity: 68.70 %|Temperature: 23.70 *C|
|17:03:24.860 → Humidity: 68.40 %|Temperature: 23.70 *C|
|17:03:26.886 → Humidity: 68.70 %|Temperature: 23.70 *C|<This seems to have been the reading
My guess is to to by hand translate the digital signal into a binary number then to recompile the given code in a C+ program to get the same output.

I note there is a can protocol decoder. A CAN protocol decoder | Dr. Ken Tindell
maybe a different logical analyzer?
Tigard??

side not these are some supporting documents… for the grove sensor… dth22…

Grove - Temperature&Humidity Sensor Pro(DHT22) | Seeed Studio Wiki

AM2302-EN.pdf

[ozindfw]

@ceramicCAP

getting that the device is a nonstandard protocol but i don’t normally verify a lot of digital components. Right now the DTH22 is being controlled by the nano, but i would like to make some custom waveforms with analog discover2 to control DTH22 and to read to the DTH22. As well i would like to feed in false data to the nano and receive false data from the nano.

I’m having a lot of trouble decoding what you are looking for. There’s not a lot of controlling of a DHT22, it looks like you ping it by cycling the bus and then listen for data.

And I don’t understand at all what you mean by “false data” Do you want to have the nano simulate the DHT22 and be able to originate a data stream you control?

This might be a conversation better had face to face. You might consider office hours

https://calendar.dallasmakerspace.org/events/view/19514

or drop me a note and I’ll let you know when I plan to be around next.

[ceramicCAP]

The signal on screen is coming from the dth22 and then going into the nano. The initial program converts the sensor data and posts it to the serial port with a value i can understand. There is the time to receive, the data process , and the time to post the data to the serial port. This makes a total amount of time i am not exact on thus i can not take into account. I believe the 40 bit information is translated into one of those 3 serial port readings but it could be later. I am looking at “pulseview” from sigrok as a future program to do logical analyzer decoding or embedded signal decoding (PulseView - sigrok) . I am using the Analog Discover 2 from Digitlent as a logic analyzer for this odd encoding. So i am using waveform program from diligent. (WaveForms Software FREE Download - Digilent) The DTH22 is a a connector board to the AM2302 to Arduino/ or seed boards. I am having a difficult time getting down to makerspace prime in Carrolton. Perhaps on the week end?
I guess i can use the extra pins to communicate receiving of the data and computation of the data. I believe when it is computing the data it would ignore any other data coming in from the bus. So i am not quite sure if all the information is accepted and computed from the sensor.

[ceramicCAP]

This is where i think i need to go. I am making a little head way. so thank you for helping.