Unanswered Questions

9
votes
2answers
2k views

How to implement critical sections on ARM Cortex A9

I am porting some legacy code from an ARM926 core to CortexA9. This code is baremetal and does not include an OS or standard libraries, all custom. I am having a failure that appears to be related ...
6
votes
0answers
481 views

Typical zero sequence data for 80MVA transformer

I need to model a 80MVA transformer 132/33kV built in 1973. There is very little information on this transformer but I need to populate certain values in the model. Where can I find typical zero ...
5
votes
0answers
115 views

GaN pulsed operation

Does anybody have experience biasing and pulsing a microwave GaN HEMT? I've just ordered a 10 Watt S-band transistor. I know all about bias sequencing. This application is pulsed. I've read about ...
4
votes
1answer
56 views

Evaluating the quality of photomasks

Photolithography would be new in our instituion and i could not ask any experts there about it, thats why i turned here. I have created a photomask using an electrolithograpy proccess and am now ...
4
votes
0answers
89 views

TMS320 Floating Point (Texas Instruments DSP from '98)

Background Is there anybody here who is an EE with programming experience who has worked with the Texas Instruments TMS320 C3X-series DSP? I am currently doing some work with the C3X for a project. ...
4
votes
1answer
104 views

limit duration 1pps signal

As a beginner in electronics, I would appreciate very much to get some input from you folks for my project, so I can decide in what direction to point my nose :) What would I like to do? I would ...
4
votes
0answers
328 views

Error interfacing GSM sim900 with atmega32

Hi all I am trying to interface GSM SIM900 with atmega32. I have a written a code in which if a user press a push button, a call will be made to a pre defined number. If we want to change the pre ...
4
votes
0answers
3k views

Msp430g2553 i2c communication library with itg3200 gyroscope

I've been creating an I2C library for communicating with ITG3200 gyroscope for MSP430g2553 experimental launchpad. I still have slight problems with sequential reading and the signed values but I'm ...
4
votes
3answers
334 views

How to control a cellphone using an Arduino?

I wish to control a classic cellphone using an Arduino Nano by connecting the cellphone keys to digital pins, and switch them using a program that I will put on the Arduino. The idea is to make a ...
4
votes
3answers
396 views

Calculating reflections

I just solved a problem in my homework. I had to calculate the reflection waves and I was given the following data: Resistance R0 = 120 Ω line impedance Ri = 90 Ω resistance at input Rb = 1 kΩ ...
3
votes
0answers
31 views

Unknown resistive disk in parallel with AC motor capacitor

This assembly is the motor connector for a Grundfos U15-38SPA circulating pump, which interfaces to the capacitor (2uF) and power supply (220VAC). Between the two brown wires leading to the cap is ...
3
votes
0answers
40 views

Altium Designer 16: Baked symbols in schematic templates

I have a small number of template projects, including project file, schematic file, PCB file and Array file. These were created in AD 14, updated to 15 and now 16. The schematic contains a number of ...
3
votes
0answers
114 views

Cannot get data to rx register of msp430fr5739

I am working on a gps project with msp430fr5739. I have done some code for gps. the nmea string handling is workings fine in my code when manually entered a few nmea sentences, but I am stuck with ...
3
votes
0answers
49 views

Design for planar antenna that radiates in the plane of the antenna

Im trying to find a reference planar antenna design. The goal would be to design an antenna that radiates omnidirectionally on the pcb plane. One solution would be to use an electrically small loop ...
3
votes
0answers
117 views

Will FCC EMC tests need to be redone?

In light of the new FCC rules that Chinese (and all non-MRA) labs will no longer recognised in July and all EMC tests need to be done at FCC-authorized Telecommunications Certification Bodies, for FCC ...

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