Notices
RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Hacking a TX, turning it into a computer radio

Old 03-03-2020, 06:40 AM
  #1  
rva1945
Thread Starter
 
Join Date: Nov 2005
Location: Buenos Aires, ARGENTINA
Posts: 629
Likes: 0
Received 0 Likes on 0 Posts
Default Hacking a TX, turning it into a computer radio

Hi:

I need to identify the wire that carries the PPM signal from the main circuitry board to the RF module, inside a HobbyKing TX.

The goal is to turn it into a computer radio. For that purpose I have to add an Arduino microcontroller, an LCD screen and of course the Arduino will have to produce the PPM signals, replacing the original circuitry. Another reason being the TX has 4 channes but the RX has 6, so I can use those extra 2 channels provided I manage to create the PPM signals.

I found 4 wires connecting the main board with the RF board, I guess they are GND, V (5v? 3.3v?) and signal, but the 4th wire leaves me puzzled. To complicate things further, I don't have an oscilloscope.

I'd appreciate any hint or help.

Thanks, Robert.
Old 03-03-2020, 08:13 AM
  #2  
AndyKunz
 
Join Date: Jun 2005
Location: White Heath, IL
Posts: 2,968
Likes: 0
Received 15 Likes on 14 Posts
Default

As noted in reply to your post on RCG, very few modern radios use PPM internally. What you likely found was a serial connection. What did your oscilloscope show you?

Andy
Old 03-03-2020, 08:17 AM
  #3  
rva1945
Thread Starter
 
Join Date: Nov 2005
Location: Buenos Aires, ARGENTINA
Posts: 629
Likes: 0
Received 0 Likes on 0 Posts
Default

Ok if it is not PPM anymore, what then?
Old 03-03-2020, 08:19 AM
  #4  
AndyKunz
 
Join Date: Jun 2005
Location: White Heath, IL
Posts: 2,968
Likes: 0
Received 15 Likes on 14 Posts
Default

Read my second sentence. The third one is helpful also.
Old 03-03-2020, 08:31 AM
  #5  
rva1945
Thread Starter
 
Join Date: Nov 2005
Location: Buenos Aires, ARGENTINA
Posts: 629
Likes: 0
Received 0 Likes on 0 Posts
Default

Well it is an old HobbyKing V1. The RX is in fact two RXs wired together.
Old 03-03-2020, 08:32 AM
  #6  
rva1945
Thread Starter
 
Join Date: Nov 2005
Location: Buenos Aires, ARGENTINA
Posts: 629
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by AndyKunz View Post
Read my second sentence. The third one is helpful also.
As I said in my post, no osc here.
Old 03-03-2020, 08:35 AM
  #7  
rva1945
Thread Starter
 
Join Date: Nov 2005
Location: Buenos Aires, ARGENTINA
Posts: 629
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by AndyKunz View Post
As noted in reply to your post on RCG, very few modern radios use PPM internally. What you likely found was a serial connection. What did your oscilloscope show you?

Andy
The Arduino is capable of serial comm. If that is the case, I should get an osc and see what is present in the line. Of course I should find a friend that owns an osc.
Old 03-03-2020, 08:38 AM
  #8  
AndyKunz
 
Join Date: Jun 2005
Location: White Heath, IL
Posts: 2,968
Likes: 0
Received 15 Likes on 14 Posts
Default

Yes, you should get a scope (that was the point in asking about it even though you said you didn't have one). You're going to need it. Let me be more clear: you are going to NEED it.

There are many types of serial communication. The scope is going to help you determine not just the hardware used, but things such as clocking. Don't be surprised if there isn't a library for what you need.

Have fun!

Andy

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.