Show Posts
Pages: [1] 2 3 4
1  Topics / Device Hacking / Re: OOK library on: April 15, 2014, 03:16:43 pm
Yes, it's 315/433 ASK/OOK SH receiver.
Protocol analyzer is what I am after.
I need to capture packets from keyfobs from garage/gate openers. The ones that are working in ASK/OOK modulation. What I want is to save the fixed codes coming from keyfobs. There are number of keyfobs with unknown protocols (at least for me), so I would like to analyze them. Looks like most keyfobs have preamble, sync word and data bits.

I am going to check those libraries, thank you!
2  Topics / Device Hacking / Re: OOK library on: April 15, 2014, 11:23:47 am
I've attached document. SYN450R - ASK/OOK receiver. Data rate I use is 1250Hz.
3  Topics / Device Hacking / OOK library on: April 15, 2014, 10:41:24 am
Is there any library for Arduino to decode OOK transmission? This is the IC that I use to receive packets. I'm trying to make general packet analyzer.
4  Using Arduino / General Electronics / Re: Logic analyzer project on: February 07, 2014, 01:20:29 pm
0-3V, can read that with Arduino directly, or maybe invert it first.
Then just use regular serial commands to read it, buffer a bunch and send it to the PC or whatever:
Code:
// declare variable, pinModes, Serial.begin, etc.
int index = 0;
byte incomingArray[1000];

//then
void loop(){
if (index <1000){
 if (Serial.available()>0){
 incomingArray[index] = Serial.read();
 index = index +1;
 }
}
else {Serial.println("array full");  // TX out to PC
  for (x=0; x<1000; x=x+1){
  Serial.println(incomingArray[x]);
  }
 }

} // end loop
If you have a Mega, can monitor Rx & Tx at the same time.
If its a UART, is there even a clock to look at?

Thanks for the code, got the point.
How can I increase input impedance of measuring part in order not to interfere device?
5  Using Arduino / General Electronics / Re: Logic analyzer project on: February 07, 2014, 01:02:35 pm
A long while ago I posted some proof of concept code in 'gigs and collaborations' as I needed someone to help with processing code but got no takers. I just searched for the thread and found it in 'Exhibition/Gallery' which confuses me as I don't remember posting it there.
It might be moved by one of the moderators as it was more a showcase than a question.
Further searching and I found the original post. I must have dumped the code in Exhibition after lack of interest and forgot I had done it (A sign of getting old)

Riva, thanks. But is it easily extensible to 3 channels? I need to capture RX/TX/CLK...
6  Using Arduino / General Electronics / Re: Logic analyzer project on: February 07, 2014, 12:44:55 pm
See Section 20 of the 328P datasheet - set the UART of the monitoring Arduino to 57K
and just receive the data normally.
Are you sure it 57K and not 57.6K?
Monitoring serial data like that is usually done with a Protocol Analyzer, not a Logic Analyzer.
Add an appropriate buffer if you want to tap into the transmitter to be monitored without adding much load. The signal to be monitored - 0/5V? RS232 (+/-3 to +/-10 or 12?)


- I'm not monitoring Arduino, but want to use Arduino to in-circuit monitor a device with UART.
- yes, 57.6kbps it is, sorry
- 0-3v logic.
- seems logic analyzer will do the job for me, as I can count bits. Protocol analyzer seems to be more complicated area.
7  Using Arduino / General Electronics / Re: Logic analyzer project on: February 07, 2014, 12:14:42 pm
yes and because of that much amount of data I am asking if anyone have experience and can recommend the project which fits above requirements.
8  Using Arduino / General Electronics / Logic analyzer project on: February 07, 2014, 12:05:13 pm
Guys,
I'm looking for some Arduino based logic analyzer project. I have Mega and UNO.
Target is to analyze UART data @ 57kbps. The problem is to have >100MOhm input attenuator I guess in order to be able to use it In-Circuit.
If anyone knows such projects, please send me the link.

Thanks
9  Using Arduino / General Electronics / Would this USB detection circuit work as expected? on: February 12, 2013, 05:43:30 am
What I am trying to achieve is detect from MCU, whenever FTDI(FT232R) chip is connected to USB(not enumerated, just powered up from USB).





- When ONLY USB is connected, MCU will get his power supply from +5V bus and will detect on (B) pin that USB is connected.

- When ONLY VR will supply power to circuit, then MCU again will get power from +5V bus, but FTDI will ONLY get VCCIO. On middle of voltage divider R10/R11 I expect there will be 0 and MCU will not detect USB connection on (B).

The question is - would it work the way I described or I missed something? My concern is it ok to hook up only VCCIO to FTDI? Would it damage or lead to unknown behavior?
10  Using Arduino / General Electronics / Re: 5 Ohm NTC to Arduino ADC? on: January 08, 2013, 03:12:10 pm
The question is not spreadsheet, but how to connect it to Arduino ADC!
11  Using Arduino / General Electronics / Re: 5 Ohm NTC to Arduino ADC? on: January 08, 2013, 11:09:49 am
Sorry, must be this pdf
12  Using Arduino / General Electronics / Re: 5 Ohm NTC to Arduino ADC? on: January 08, 2013, 10:41:50 am
Sure, this is datasheet
13  Using Arduino / General Electronics / Re: 5 Ohm NTC to Arduino ADC? on: January 08, 2013, 08:39:35 am
I understand that, but what value of bias resistor should I select? 10k? 100Ohm? The more is bias resistance value, the less precision I will get?
14  Using Arduino / General Electronics / 5 Ohm NTC to Arduino ADC? on: January 08, 2013, 08:22:34 am
I need to use NTC 5D-20 to measure temperature.
It has 5 Ohm R0 and 3150 Beta. The temperature I'm interested in +20...+70C.
It appears that resistance range would be from 1-5 Ohm, which is very little. What bias resistor should I use? How tto connect to Arduino ADC with less non-linearities?
15  Using Arduino / General Electronics / Re: How to suppress terrible noise from MAX7219? on: January 01, 2013, 12:22:25 pm
Let's see what I will have after I make PCB instead of this horrible wires.
Will update this post.
Pages: [1] 2 3 4