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cameronl : rf   50

DIY Arduino based RC Transmitter - (How To Mechatronics) YouTube
NRF24L01, 700 meter max range, arduino pro mini, jlcpcb.com, custom rf protocol
design  acrylic  remote  control  wireless  rf  arduino  joystick  pcb  electronics 
january 2019 by cameronl
CC430 frequency shift when powered after progam - MSP low-power microcontroller forum - MSP low-power microcontrollers - TI E2E Community
// Loop until XT1,XT2 & DCO stabilizes
do {
UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);
// Clear XT2,DCO fault flags
SFRIFG1 &= ~OFIFG; // Clear fault flags
} while (SFRIFG1&OFIFG); // Test oscillator fault flag
cc430  microcontroller  rf  crystal  oscillator  stability  fault 
january 2019 by cameronl
Shielding and Guarding | Analog Devices (1983)
"How to Exclude Interference-Type Noise; What to Do and Why to Do It—A Rational Approach"
emi  rf  noise  filter  shield  guard  electronics  design 
december 2017 by cameronl
RF Connectors | Newark element14
u.FL (Micro coax, Amphenol, Molex), SMA straight, SMA edge, surface mount, thru-hole, right-angle..
Looks good.
rf  connector  electronics  pcb 
november 2017 by cameronl
AN098 - Layout Review Techniques for Low Power RF Designs - swra367a.pdf | ti.com
- CC1101, CC430, etc. SmartRF
- "TI LPRF reference designs are...recommended to be copied exactly"
- "Impedance matching is critical"
- "how to include a test/debug port in the prototype design for easy and quick radio performance testing."
radio  rf  design  pcb  layout  electronics 
october 2017 by cameronl
AN096 Using CC1190 Front End with CC1101 under FCC 15.247 (Rev. A) - www.ti.com [swra361a.pdf]
"RF shielding is necessary to keep the radiated harmonics below the regulatory limits."
rf  amplifier 
september 2017 by cameronl
Calculation and usage of LQI and RSSI - Design Notes - Wireless Connectivity - TI E2E Community
LQI (Link Quality Indicator)
RSSI is a signal strength indication.

cc1101, cc430
rf 
september 2017 by cameronl
Understanding RSSI and LQI values reported by the CC1101 | WISENSE
"The RSSI value reported by the CC1101 is a 8 bit signed number with an effective range from -138 dBm to -10.5 dBm when the CC1101 is operating around 868 MHz. The LQI value reported by the CC1101 is a 7 bit unsigned number with a range from 0 to 127. Note that a lower value indicates a better link."
rf 
september 2017 by cameronl
#84: Basics of Ferrite Beads: Filters, EMI Suppression, Parasitic oscillation suppression - YouTube (w2aew)
Ferrite beads, inductors, filters, EMI, noise, RF, power supply, coupling/decoupling
Oscilloscope bandwidth, frequency content of square wave
Signal/function generator, sweep of frequencies
electronics  noise  filter  bandwidth  inductor  rf 
july 2017 by cameronl
SMPS noise reduction - forum.allaboutcircuits.com
"The frequency at which the noise repeats is not what you have the problem with: look at the noise waveform. The sharply rising edges have components that go into the hundreds of Mega Hertz. That's whay they are so hard to kill"

"Use a low pass filter. As stated, you must use caps that are good at mega hertz ranges like ceramic caps and possibly polyester film caps. Aluminum electrolytics and tantalums will have very little effect since the noise frequencies are above their resonant frequency."

More good stuff in this thread...
electronics  noise  filter  emi  rf  audio  essential 
july 2017 by cameronl
Michael Ossmann: Simple RF Circuit Design - YouTube
5 rules for RF PCB design:
1. 4 Layer PCB (consistent stack)
2. IC's whenever possible (filter, balun, transceiver, etc.)
3. 50 Ohm everywhere (use a calculator)
4. Follow manufacturer recommendations
5. Trace RF first
radio  rf  electronics  design  pcb 
november 2016 by cameronl
microcontroller - What causes UART errors? - Electrical Engineering Stack Exchange
"There are several potential sources for noise in any circuit. Some of the most common include:

Poorly regulated power supplies;
Switching power supplies;
Insufficient capacitive decoupling of the power rails near the MCU;
Inductive coupling of nearby electromagnetic sources (including 50 or 60Hz from the mains power; even if the circuit is battery powered, it will experience this interference when close enough to a mains source);
RF sources near the resonant frequency of a trace on the circuit board, or one of its harmonics;
Routing of high-current traces on the circuit board near signal lines"

http://electronics.stackexchange.com/questions/33228/with-shielded-twisted-pair-cable-do-you-ground-one-end-both-ends-or-neither-e
https://en.wikipedia.org/wiki/Ground_loop_%28electricity%29
noise  electronics  rf 
august 2015 by cameronl
CC1101 RF module tests with arduino logic level converters PART1 (Ben Biles) - YouTube
cc1101, SPI, Logic level converter (5v to 3.3v), Gqrx, tv dongle, SDR (software defined radio), arduino clone
sdr  software  radio  rf  wireless  hardware  electronics  arduino 
august 2015 by cameronl
Measuring relative antenna performance -- Modding junk 900 Mhz antenna - Page 2 - RC Groups
"Anyone know where to buy a cheap 900Mhz SWR meter?

- Using the RSSI output on your A/V Rx is a very effective solution for measuring relative antenna performance as you optimize the element length at the Tx. Won't cost you a dime either."
wireless  rf  radio  antenna  design 
july 2015 by cameronl
1:1 SWR - Google Search
Understanding SWR by Example :: Take the mystery and mystique out of standing wave ratio.
http://www.arrl.org/files/file/Technology/tis/info/pdf/q1106037.pdf
wireless  rf  radio  antenna  design 
july 2015 by cameronl
433Mhz range | AVR Freaks
^"if you don't know the impedance a slim jim antenna would be a good start.(just google)"

Slim Jim and J-Pole calculator
http://www.m0ukd.com/calculators/slim-jim-and-j-pole-calculator/

Good resource - Slim Jim antenna
http://www.hamuniverse.com/slimjim.html

"Slim Jim Antenna delivers up to 6dbi of gain on the 440 – 470 Mhz UHF bands, which is almost twice the gain of a J-Pole and 5 times the gain of a 1/4 wave ground-plane antenna."
http://www.jpole-antenna.com/shop/uhf-440-470-mhz-slim-jim-antenna/
wireless  rf  radio  antenna  design 
july 2015 by cameronl
SmartRF Studio (Texas Instruments) - Google Search
"SmartRF™ Studio is a Windows application that can be used to evaluate and configure Low Power RF-ICs from Texas Instruments."
wireless  rf  radio  design  software 
july 2015 by cameronl
PIC project, using cheap RF modules! - romanblack.com/RF/cheapRFmodules
^ Lots of detail.

http://www.avrfreaks.net/comment/1135851#comment-1135851
"You need a "solid" ground plane to match it.
You can buy antennas or make them your self.
Look what HAM people do for the 70cm band.
I don't know where you live but there a rules about max effect and about % of the time you can be on the air (something like 2% of the time and never more than 30 sec on one transmit).
Add
and there are a big difference between 9600 baud and a <100 baud garage opener (ook like Morse code)."
rf  radio  microcontroller  antenna 
june 2015 by cameronl
Lab 3: spectrum analyzer, RSSI vs. distance [pdf] - wsn.eecs.berkeley.edu
"Poor Man’s Spectrum Analyzer
CC2500 can easily change its operating frequency, through the use of channels.
...build a spectrum analyzer by continuously plotting noise vs. frequency."
MSP430
spectrum-analyzer  wireless  rf 
april 2015 by cameronl

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