PIC16F84 RF howto

[dlconejos]

hello guys. im pretty much new to PIC. Id like to create and RF program in PIC16F84, please guide me on what to do

 

[Nigel Goodwin]

Check my tutorials!, they use the 16F628, which replaced the 16F84 last century!.

 

[TiagoSilva]

Have you check the RF Pic's ? They are the best for RF Control aplications such as remote control key's and stuff like that ... pretty small too and easy to program like the rest, give it a try. With theese you don't need RF Modules with external uC !!!

 

[Nigel Goodwin]

Have you check the RF Pic's ? They are the best for RF Control aplications such as remote control key's and stuff like that ... pretty small too and easy to program like the rest, give it a try. With theese you don't need RF Modules with external uC !!!

But they are also a LOT more difficult to use, require a PCB to use them, and (presumably) won't comply to licence free status unless you send samples of the completed units for testing (BIG money!).

 

[TiagoSilva]

Worth the try !!!

 

[dlconejos]

Im very much happy for your reply guys. U know im just a baby to this technology. Anyhow, the things that id like to do is as follows:
1. Using PC, connect a single PIC-based RF/Ultrasonic module (PIC16F84/PIC16F877) to the RS232 interface of the PC. ( But as of now i really dont know how to do it!)
2. Another module PIC-Based RF/Ultrasonic module (not connected to the PC)[external]. This will beam towards [1] module. From their if possible, i will simulate it from the PC that there is an interaction or communication between the two PIC-based module.

I hope you can englighted me on what to do. Where should I start and how?
In our country, which is thirld world country we only PIC16F84 and PIC16F877.

Thank you so much in advance.

 

[Nigel Goodwin]

Im very much happy for your reply guys. U know im just a baby to this technology. Anyhow, the things that id like to do is as follows:
1. Using PC, connect a single PIC-based RF/Ultrasonic module (PIC16F84/PIC16F877) to the RS232 interface of the PC. ( But as of now i really dont know how to do it!)
2. Another module PIC-Based RF/Ultrasonic module (not connected to the PC)[external]. This will beam towards [1] module. From their if possible, i will simulate it from the PC that there is an interaction or communication between the two PIC-based module.

I hope you can englighted me on what to do. Where should I start and how?
In our country, which is thirld world country we only PIC16F84 and PIC16F877.

As I said above, check my tutorials, they already contain everything you need!.

 

[TiagoSilva]

Also, if you just need to connect a RF Module to your computer via RS-232 you only need to get a MAX232 to do the voltage level interface, usually RS-232 PC ports have 12V lines, and the modules 5V lines.

This is if you only need to make a wireless connection to the other module !

Anyway, pic accept Hi level's on the I/O pins but they don't give more than 5V ...

To enlight you, the MAX232 is a RS-232 <-> TTL converter, very known also ... cheap too ...

 

[dlconejos]

ok. right now. i will purchase the necessary tools and ic's i nid to start. ill ask you guys [gurus]. to help me. thank you so much.

 

[TiagoSilva]

No problem, anyway, where are you from ?

 

[dlconejos]

Im from the Philippines

 

[dlconejos]

i visited the site http://www.winpicprog.co.uk. it is very interesting.

anyhow i wud like to ask has anybody have done this one?

1. TX sends a signal to RX [RF/Ultrasound base] then the RX side computes/measures signal propagation time to obtain the location of the TX(transmitter)

any ideas guys?

 

[Nigel Goodwin]

i visited the site http://www.winpicprog.co.uk. it is very interesting.

anyhow i wud like to ask has anybody have done this one?

1. TX sends a signal to RX [RF/Ultrasound base] then the RX side computes/measures signal propagation time to obtain the location of the TX(transmitter)

any ideas guys?

Yes, it's called GPS - it's not practical to do it yourself, the progation time of RF is the speed of light, as fast as the electronics you're trying to measure it with!.

 

[dlconejos]

plz. correct me if i am wrong. but it may seems like a GPS [indoor gps system]. there are however other systems that have implemented this one, but not using PIC, i believ this wud be an interesting thing to do. others use ULTRASONIC sensors.

im very optimistic that this can be done in PIC. although, im not familiar with it.
hope u can help me....

 

[dlconejos]

Ultrasound distance measurement howto

anybody, can help on how to implement an ultrasonic distance measurement?

 

[TiagoSilva]

well IR uses a similar method so you can use an 555 to generate an ultrasonic freq. an then conect the ultrasound receiver to an amplifier circuit and filter and then to the microcontroler A/DC that might workout ... but it needs perfection ... and if you don't even know the basics then search for a circuit on google who knows ... oh, the IR usually work on 37 Khz i guess and the receiver have an digital output, it's simpler ... Ultrasonic need more power and must also be filtered for signal noises ...

 

[dlconejos]

Thank you sir.. Ur right but unfortunately, it must be an ultrasonic sensors. I would like to use the theory TDOA (time difference of arrival). I think i can use ulltrasonic and RF at the same time, according to theory. but i nid ur help guys on how to do it.

 

[TiagoSilva]

To help ... Hmm i've never have done anything like that but you can check this module that parallax has ... https://www.parallax.com/detail.asp?product_id=28028 ... It's a little bit expensive but if you can get the schematics in the web or for something alike you can do this easyer

 

[dlconejos]

Thank you sir. ur right its a bit expensive. my plans is to use:
4 nodes
1. PIC16F877 (4)
2. ultrasonic transceiver (2)/node
3. RF transmitter per node

Hope anyone can help me on this one

 

[hjames]

Time of flight using sound can definitely work, but using radio to trigger is a little tricky. Most RF receivers have jitter - and lots of it - a good estimate might be that the worst case timing accuracy you'll get off of RF is probably ~30% of a bit time. If you can filter this well enough and have a high enough bit-rate, you might be able to use this.

However, if you have 4 receivers that are located at known positions, and can hear a "ping" that is sent by a remote transmitter, then you can back out the 3D position of the source. (If you know the exact time of broadcast, then you only need 3 receivers.)