Search found 44 matches

by 60amp_relay
Fri May 28, 2010 5:01 pm
Forum: Wireless/RF
Topic: Bit Error Rate (BER) in affordable transmitter
Replies: 3
Views: 444

Re: Bit Error Rate (BER) in affordable transmitter

It's all about how you design your protocol, and what kind of data rate you need. I'm assuming you'll have a laptop/Arduino/PIC/Atmel/or similar at each end. You can use something like these: http://www.sparkfun.com/commerce/product_info.php?products_id=8946 http://www.sparkfun.com/commerce/product_...
by 60amp_relay
Thu May 27, 2010 6:00 pm
Forum: BatchPCB
Topic: My order hasn't arrived in 2 months...
Replies: 8
Views: 2245

Re: My order hasn't arrived in 2 months...

FWIW, I had the same problem. I'm not complaining or anything, but there might be some value in others seeing my experience. I had an order on panel 750 that simply disappeared. I was pretty bummed about it. The BatchPCB folks say it was shipped, and USPS claims to have never received it. It's one o...
by 60amp_relay
Wed May 26, 2010 2:42 pm
Forum: Wireless/RF
Topic: Help with relay switch
Replies: 6
Views: 936

Re: Help with relay switch

You'll need two Arduinos in order to make this happen. PIR --> Arduino 1 --> RFLink Transmitter RFLink Receiver --> Arduino 2 The reason for this is that you need to have a 0-to-1 or 1-to-0 transition on the transmitter's data pin at least once every 30 milliseconds (e.g. the minimum baud rate is 30...
by 60amp_relay
Sat May 22, 2010 9:55 am
Forum: Wireless/RF
Topic: RF 434MHz, turning on and off an LED
Replies: 5
Views: 917

Re: RF 434MHz, turning on and off an LED

This transmitter / receiver pair has a maximum pulse width of around 30 milliseconds. If you hold a steady voltage on the transmitter's data pin for any longer than 30ms, then the automatic gain control on the receiver will drift away and it loses the signal. One thing you could try would be to use ...
by 60amp_relay
Sun May 09, 2010 5:57 pm
Forum: Arduino
Topic: RC Car Controlled by Arduino and Xbox360 Controller
Replies: 17
Views: 11565

Re: RC Car Controlled by Arduino and Xbox360 Controller

You could try using an L298N. Those things have a lot more grunt, and there's a large metal backing plate to attach a heat sink.

Do you have an amp meter you could use to measure the stall current on your main motor? The motor I'm using stalls at 2.2 amps @ 5V.
by 60amp_relay
Fri May 07, 2010 6:29 pm
Forum: SparkFun Product Questions
Topic: 5V Step-Up at 1 Amp?
Replies: 6
Views: 882

Re: 5V Step-Up at 1 Amp?

You could always buy 3 of them and gang them together for up to 900mA output. Or take two batteries wired in serial for 3.7v + 3.7v = 7.4v and use a voltage regulator to get it back to 5v. A good voltage regulator can do 1000mA natively.
by 60amp_relay
Sun Apr 18, 2010 12:48 pm
Forum: Wireless/RF
Topic: TWS/RWS-434 Wireless Link Range issues
Replies: 2
Views: 951

Re: TWS/RWS-434 Wireless Link Range issues

Just a shot in the dark here, but the solderless breadboard has an inch or so of wiring between the holes under the plastic which may have been acting like an antenna, and boosting your range. The protoboard may not be giving you the same ad-hoc antenna if it has shorter copper pads or traces. Or ma...
by 60amp_relay
Tue Apr 13, 2010 2:32 pm
Forum: SparkFun Site Questions/Comments
Topic: FT232RL Solder Jumper Picture
Replies: 12
Views: 47955

FT232RL Solder Jumper Picture

On the pictures of the FT232RL on the web site, a few people (including myself) had a little trouble seeing the solder jumper. It was easy to locate it once I had bought the board, but it would be nice if there were a zoomed-in photo showing exactly where it is. I'm posting this picture so that hope...
by 60amp_relay
Wed Mar 31, 2010 6:00 pm
Forum: Wireless/RF
Topic: 315 MHz TX/RX module interfacing
Replies: 11
Views: 1207

Re: 315 MHz TX/RX module interfacing

This is the receiver program, also using a PIC16F630: #include <htc.h> #pragma warning disable 750 #define OUTPUT 0 #define INPUT 1 #ifndef _XTAL_FREQ #define _XTAL_FREQ 4000000 #endif /* At a TMR0 1:8 prescaler, 200 ticks = 600 baud */ /* This has been tested to about 50 feet, and seems to work fai...
by 60amp_relay
Wed Mar 31, 2010 5:57 pm
Forum: Wireless/RF
Topic: 315 MHz TX/RX module interfacing
Replies: 11
Views: 1207

Re: 315 MHz TX/RX module interfacing

For some reason, it looks like I can't upload a C program, I'll try to cut & paste instead: The RFLink Transmitter program follows. This is for a radio-controlled tank, using a PIC16F630: /* RC Tank Transmitter */ #include <htc.h> #pragma warning disable 750 #define OUTPUT 0 #define INPUT 1 #ifndef ...
by 60amp_relay
Wed Mar 31, 2010 4:50 pm
Forum: Wireless/RF
Topic: 315 MHz TX/RX module interfacing
Replies: 11
Views: 1207

Re: 315 MHz TX/RX module interfacing

I wouldn't put -5V on the data line... usually the absolute minimum is only -0.3V or so. But there's lots of ways to get your signal into the +0V to +5V range that this unit requires.

I'll post my PIC code here in a minute.
by 60amp_relay
Sat Mar 27, 2010 9:51 am
Forum: Wireless/RF
Topic: 315 MHz TX/RX module interfacing
Replies: 11
Views: 1207

Re: 315 MHz TX/RX module interfacing

I've had success using these same modules. I'd be glad to post my C code if you're interested. The library is for a PIC microcontroller, but the basic ideas should be portable to any TTL device. I used something akin to Manchester encoding to get it working, with a sync byte at the start of the data...
by 60amp_relay
Mon Mar 08, 2010 3:33 pm
Forum: BatchPCB
Topic: My 1st Order
Replies: 12
Views: 4501

Re: My 1st Order

I just got my first PCB too. It works great! Even with the custom-sized drill holes and pads that I used, everything was done correctly and it works perfectly.
by 60amp_relay
Fri Feb 26, 2010 12:48 pm
Forum: PIC Microcontrollers - Software and Hardware
Topic: Three-legged race: Programming a PIC16F630 with Basic Stamp
Replies: 3
Views: 873

Three-legged race: Programming a PIC16F630 with Basic Stamp

I know that most of you guys are already experts in this field, and PIC programming is old-hat. I also know that PIC programmers can be had for under $20, which renders most of this project moot. But if you'll indulge me a few minutes, I just finished what was, for me, a pretty significant (and fun!...