Search found 1947 matches

by phalanx
Fri Feb 23, 2018 7:08 am
Forum: Projects
Topic: Jeep brake/tail lights
Replies: 9
Views: 130

Re: Jeep brake/tail lights

That's an excellent start to your project. I wish more people would write down details in that manner. It would help them and anyone providing assistance during the implementation stage. If you intend to work though this on your own, you are at the point where you will need to start learning about s...
by phalanx
Mon Feb 19, 2018 11:03 am
Forum: Projects
Topic: Jeep brake/tail lights
Replies: 9
Views: 130

Re: Jeep brake/tail lights

You are correct. Modeling can much more than a mathematical formula. To tackle a project like this, you need to know a number of things. For example: Inputs: What signals are available? What states can they be in (including transitions between states)? Are there any characteristics of the inputs tha...
by phalanx
Wed Feb 14, 2018 9:19 pm
Forum: Projects
Topic: Jeep brake/tail lights
Replies: 9
Views: 130

Re: Jeep brake/tail lights

One thing I overlooked that will definitely help you out is you have a 3rd brake light signal that should be independent of your tail lights. In any single mode of operation, it will be easy to determine whether a brake, hazard, or directional has been triggered. Where things get more complicated is...
by phalanx
Wed Feb 14, 2018 6:42 am
Forum: Projects
Topic: Jeep brake/tail lights
Replies: 9
Views: 130

Re: Jeep brake/tail lights

This is certainly doable but there are some aspects of how the electrical system in a vehicle works that you need to consider. The first problem is how do you get power for your device? When used as a brake light, you have power available as long as you have your foot on the brake. How do you handle...
by phalanx
Mon Feb 12, 2018 12:54 pm
Forum: PIC Microcontrollers - Software and Hardware
Topic: PIC I2C using Colour sensor
Replies: 4
Views: 778

Re: PIC I2C using Colour sensor

I apparently forgot to look at this post again after replying the first time.

Avianate, there are lots of reasons why your SDA and SCL lines could be stuck low. We will need more information on your setup and initialization code for your PIC before we can be of any more help.

-Bill
by phalanx
Thu Feb 01, 2018 8:18 am
Forum: Arduino
Topic: Trying To Measure Impact Force?
Replies: 6
Views: 102

Re: Trying To Measure Impact Force?

Without access to the system, no one can say whether or not a 500Hz sampling rate is adequate. To know for certain, you should look at the output of your resistor using an oscilloscope to capture an impact so you can measure the actual duration of the event and set your sampling rate accordingly. -B...
by phalanx
Wed Jan 31, 2018 11:02 am
Forum: Arduino
Topic: HX711 + loadcell measurement offset when first switching relay
Replies: 9
Views: 220

Re: HX711 + loadcell measurement offset when first switching relay

My mistake. For whatever reason I didn't see your diode around the coil of the relay. The way you have it installed is correct.

-Bill
by phalanx
Mon Jan 29, 2018 3:20 pm
Forum: Arduino
Topic: HX711 + loadcell measurement offset when first switching relay
Replies: 9
Views: 220

Re: HX711 + loadcell measurement offset when first switching relay

The relay you are using is a SRA-05VDC-CL which has a 5V 0.6 Watt coil, so it draws a nominal 120mA. In the grand scheme of things, that's not a lot of power, but relative to everything else in your project, it's huge. Now that you are saying everything appears to be working properly when you jump t...
by phalanx
Mon Jan 29, 2018 9:39 am
Forum: Arduino
Topic: HX711 + loadcell measurement offset when first switching relay
Replies: 9
Views: 220

Re: HX711 + loadcell measurement offset when first switching relay

While your USB phone charger has enough power to keep everything running, it was not designed with sensitive analog electronics in mind. The small shift in output voltage when you energize the relay has no effect on your digital electronics because everything is still in spec, but your analog electr...
by phalanx
Sun Jan 28, 2018 3:41 pm
Forum: Arduino
Topic: HX711 + loadcell measurement offset when first switching relay
Replies: 9
Views: 220

Re: HX711 + loadcell measurement offset when first switching relay

Sorry for the delay but I've been busy this weekend. It's definitely the relay causing the regulated voltage to sag slightly. Fortunately there are a few ways you can attack the problem. The simplest would be to use a more powerful 5V supply since your current one doesn't seem to be quite up to the ...
by phalanx
Fri Jan 26, 2018 5:45 pm
Forum: Arduino
Topic: HX711 + loadcell measurement offset when first switching relay
Replies: 9
Views: 220

Re: HX711 + loadcell measurement offset when first switching relay

This is a result of small changes in your supply voltage due to the load it is powering. Your relay is drawing enough current that your voltage reference is slightly shifting which in turn affects the measurements from your load cell. What you need to do is isolate the power to your relay from the r...
by phalanx
Wed Jan 24, 2018 5:24 pm
Forum: SparkFun Site Questions/Comments
Topic: Can't access LTspice forum
Replies: 5
Views: 806

Re: Can't access LTspice forum

My follow-up PMs to the person who requested the forums have gone unread. I'm reluctant to make them publicly viewable if no one is supporting them. I'll see if I can get any more information but I can't promise anything.

-Bill
by phalanx
Fri Jan 19, 2018 6:28 am
Forum: SparkFun Product Questions
Topic: Load cell accuracy for small forces
Replies: 1
Views: 71

Re: Load cell accuracy for small forces

Since load cells are analog devices, your resolution is ideally infinitesimally small. In the real world, you are limited by the noise in your system and the resolution of your A/D converter. Let's make some assumptions so I can illustrate what I'm talking about. Let's assume that you have a 10-bit ...
by phalanx
Fri Jan 05, 2018 6:00 am
Forum: Wireless/RF
Topic: 802.11AC 5GHz
Replies: 11
Views: 2802

Re: 802.11AC 5GHz

It's important because... 1. No one is getting rid of 2.4 anytime soon. 2. 2.4 has better range than 5.8. Low frequencies carry farther and are less likely to be disrupted by walls and other obstructions. If that's not the case in your house, you likely have a hardware or configuration issue. 3. Fo...
by phalanx
Wed Dec 06, 2017 7:49 am
Forum: PIC Microcontrollers - Software and Hardware
Topic: MCP79410-Days of week
Replies: 1
Views: 674

Re: MCP79410-Days of week

When setting an alarm, DATE and MONTH do not account for what year you are in and the DAY OF WEEK of any given DATE will change year to year. For whatever reason, YEAR isn't part of the alarm options so you have to deal with the DAY OF WEEK field.

-Bill