Search found 2171 matches

by jremington
Thu Jun 21, 2018 2:36 pm
Forum: PIC Microcontrollers - Software and Hardware
Topic: Newbie to PIC - distance sensing and chip selection
Replies: 3
Views: 21

Re: Newbie to PIC - distance sensing and chip selection

You can put an Arduino-compatible processor chip on any PCB that you design, same as for a PIC.
by jremington
Thu Jun 21, 2018 9:36 am
Forum: PIC Microcontrollers - Software and Hardware
Topic: Newbie to PIC - distance sensing and chip selection
Replies: 3
Views: 21

Re: Newbie to PIC - distance sensing and chip selection

Pololu has an excellent selection of analog distance sensors: https://www.pololu.com/category/189/proximity-sensors-and-range-finders I use MPLAB for Pic programming, but now find Arduino much more convenient, much easier to program and far more powerful. You can't beat the Pro Mini for price, size ...
by jremington
Tue Jun 19, 2018 7:48 am
Forum: SparkFun Product Questions
Topic: MLX90632 - No reading any temperature
Replies: 1
Views: 53

Re: MLX90632 - No reading any temperature

If you are using 5V Arduinos, how is it wired, and/or what are you using for the required logic level shifters with that 3.3V device? If you are not using a logic level shifter, you have to be extremely careful to check that appropriate pullup resistors are used and connected to 3.3V ONLY. The Mega ...
by jremington
Sun Jun 17, 2018 12:52 pm
Forum: SparkFun Product Questions
Topic: DS1307 RTC
Replies: 2
Views: 65

Re: DS1307 RTC

If there is a good backup battery on the DS1307 module, it will keep time when the power is off. Post a link to the module you have. The DS1307 is a poor timekeeper and will typically gain or lose a minute or two every day. The DS3231 is much better. It is tricky to set any RTC to the correct time, ...
by jremington
Thu Jun 14, 2018 8:05 pm
Forum: Projects
Topic: Rocket accelerometer
Replies: 13
Views: 209

Re: Rocket accelerometer

so why would it be wasted?
Because a primary function of the Kalman filter is to merge information from two or more sources. Used with only one source, a Kalman filter reduces to a simple low pass filter.
by jremington
Tue Jun 12, 2018 4:01 pm
Forum: Projects
Topic: help with code to control 32x64 matrix with mega 2560
Replies: 2
Views: 57

Re: help with code to control 32x64 matrix with mega 2560

I have no knowledge of writing code and I cannot find any suitable examples online. Then please be aware that this is a ridiculous choice for a first project -- trying to run before you can even crawl. Expect endless frustration if you don't start small: learn the programming language, learn to bli...
by jremington
Sun Jun 10, 2018 4:54 pm
Forum: SparkFun Product Questions
Topic: CO₂ Humidity and Temperature Sensor - SCD30
Replies: 2
Views: 52

Re: CO₂ Humidity and Temperature Sensor - SCD30

Did you follow the burn-in instructions on the sensor product page? If so, please describe what happened during the burn-in period. Best to log the output to a file over time. Note: The SCD30 has an automatic self-calibration routine. Sensirion recommends 7 days of continuous readings with at least ...
by jremington
Sat Jun 09, 2018 8:04 pm
Forum: PCB Design Questions
Topic: splitting a 0-5v signal
Replies: 2
Views: 69

Re: splitting a 0-5v signal

That is the usual approach. You will need a rail-to-rail op amp, or a separate (possibly bipolar) power supply that allows a less capable op amp to cover the entire 0-5V range.
by jremington
Sat Jun 09, 2018 8:16 am
Forum: Projects
Topic: Stepper motor burned out the driver
Replies: 1
Views: 38

Re: Stepper motor burned out the driver

Note that setSpeed() takes a long integer argument, not floating point. https://www.arduino.cc/en/Reference/StepperSetSpeed A loose connection on a motor lead, or attempt to connect/disconnect the motor while the driver while powered, will destroy any motor driver instantly. The L298 has overtempera...
by jremington
Fri Jun 08, 2018 9:23 am
Forum: Projects
Topic: Rocket accelerometer
Replies: 13
Views: 209

Re: Rocket accelerometer

Alignment of two 3D accelerometers is not required. Just measure a single acceleration (e.g. g) as a 3D vector on each, to get the relative orientation of one to the other.
by jremington
Thu Jun 07, 2018 7:19 pm
Forum: Projects
Topic: Rocket accelerometer
Replies: 13
Views: 209

Re: Rocket accelerometer

What you are doing is integrating the acceleration and waiting for the velocity to go from positive to negative. Agreed. How is that better done with a 100 g accelerometer, near apogee when the engine is not firing? I think you would want both, to more accurately measure the two acceleration regimes.
by jremington
Thu Jun 07, 2018 5:55 pm
Forum: Projects
Topic: Rocket accelerometer
Replies: 13
Views: 209

Re: Rocket accelerometer

@UhClem: Don't you agree that for apogee detection, one would want to use a +/- 2g (or similar) accelerometer? I suspect that with a 100 or 200 g scale, the acceleration near apogee would be lost in the noise.
by jremington
Tue Jun 05, 2018 8:48 am
Forum: Arduino
Topic: randomSeed function doesn't work
Replies: 2
Views: 70

Re: randomSeed function doesn't work

You have to use a different value for the randomSeed argument every time, to get a different sequence. It is not guaranteed that an unconnected or "floating" analog input will provide suitable numbers. Is A0 actually unconnected, in your case? Try printing out the value returned by analogRead(A0) to...
by jremington
Mon Jun 04, 2018 11:50 am
Forum: Projects
Topic: Convert a circuit from 24 to 12vdc
Replies: 6
Views: 128

Re: Convert a circuit from 24 to 12vdc

4-20 mA interfaces are industry standard since about 1950, and many companies sell them. There are also interface ICs that are dedicated to the task, for example from Analog Devices: http://www.analog.com/en/products/interface-isolation/4-20-ma.html See this article: https://www.sensorsmag.com/compo...
by jremington
Wed May 30, 2018 9:54 am
Forum: SparkFun Product Questions
Topic: MPU-6050 doesn't reach 90 degrees
Replies: 1
Views: 39

Re: MPU-6050 doesn't reach 90 degrees

Your software may be wrong, or you may need to calibrate the accelerometer, as described here: https://thecavepearlproject.org/2015/05 ... r-arduino/