Unanswered Questions

5
votes
0answers
202 views

Unable to get bootloader working on custom PCB with AT32UC3L

I have designed a PCB for a client recently, everything is fine with the hardware and software (application is working as it is supposed to). Now we are facing the need to update the program inside ...
5
votes
1answer
102 views

Industry standard measure for coaxial cable stiffness?

Is there an industry standard measure for coaxial cable stiffness? By stiffness I mean the spring force experienced when bending or deforming the cable. In my search for a highly flexible lab test ...
5
votes
1answer
402 views

Why is the loaded Q of a critically coupled two-resonator circuit approximately equal to 0.707 times the loaded Q of one of its resonators?

From RF Circuit Design by Christopher Bowick (page 32 bottom of the page left column): The loaded Q of a critically coupled two-resonator circuit is approximately equal to 0.707 times the loaded ...
4
votes
1answer
98 views

How power system is designed for extreme small system, such as google contact lens?

I just read this news and got very curious: http://www.takepart.com/article/2014/07/23/goodbye-finger-pricking-how-googles-smart-contact-lens-really-helps-diabetics Google is designing "Google ...
4
votes
0answers
30 views

Stop mask errors in DRC

I'm doing my first board in Eagle (first board at all, actually) and am getting a lot of stop mask errors around parts that I'm using out of the Nordic and Adafruit libraries. Every point of ...
4
votes
2answers
134 views

Should I keep the decoupling capacitor's vias isolated from ground fills?

I'm finishing up a PCB layout which contains a 6.5 GHz ultra-wideband transceiver with a chip antenna, an ARM controller running at 72 MHz with a 12 MHz crystal, a 16 MHz SPI bus with 3 peripheral ...
4
votes
0answers
133 views

AHRS algorithm under continuous linear accelerations

I have tried several algorithms to get pitch, roll and yaw under continuous linear accelerations and vibrations (smaller than 0.4g, frequency lower than 10HZ). None of them give good results because ...
4
votes
1answer
204 views

Safe shutdown/restart Raspberry Pi due to a power loss

I am a total beginner in electronics so I need your advice. Does this simple circuit provide for a safe shutdown, with two super caps of 10F? (Original image)
4
votes
1answer
318 views

DIY NFC boosting antenna for a mobile device

I am very new to this. I'm a dentist trying to improve client flow in a busy office. I would like to develop a cheap proof of concept for an NFC enabled client tracking system using a hacked mobile ...
4
votes
2answers
220 views

How to measure the PWM current with a DMM

I have a Fluke 87V, which is a True-RMS DMM, and I would like to measure the current in my circuit. I have 2 motors being driven by a PWM so I wonder if the DC current or the AC current measurement of ...
4
votes
0answers
221 views

Arduino to Android serial communication issue

I've been trying to use this serial for android library now, but I can't make it work. I'm trying to run this little program in android: ...
4
votes
2answers
408 views

Why does ADC conversion time vary?

I'm using TI Tiva C TM4C123GH6PM on a Launchpad combined with an AD 9850 DDS to create frequency modulator. Currently I have an extremely simple program which basically sets up microcontroller's ...
4
votes
0answers
194 views

Simulating a magnetic field in Spice

I am trying to simulate a circuit that involves pickup coils in Spice. How would one simulate the magnetic fields that the pickup coils can sense? Additionally, how would one get a frequency response ...
4
votes
0answers
104 views

Implementation of AES algorithm using Systolic architecture

I need to generate a VLSI Systolic array to implement the AES encryption algorithm with key length of 128 bits. Following are the possible ways : Systolic for Key expansion Systolic in MixColumn ...
4
votes
1answer
469 views

SPI Read returns only 0 in slave when I hook up SS to INT

I am coding a SPI slave using a PIC16F877A in CCS C and need to be aware when the SS line (pin 7) goes from high (idle) to low (active) as information from the master is framed as a stream of bytes ...

15 30 50 per page