Search found 1740 matches

by Valen
Sat Sep 15, 2018 7:55 am
Forum: Projects
Topic: Auto Cat Feeder
Replies: 1
Views: 240

Re: Auto Cat Feeder

1: You lack a diode across the motor terminals. Once the transistor shuts off the energized coil causes a voltage spike that could damage the transistor. Connect the diode such that the cathode is on the positive motor terminal. When the transistor turns off the current can flow back to the positive...
by Valen
Sat Sep 15, 2018 7:00 am
Forum: Projects
Topic: Dog proximity sensor
Replies: 1
Views: 228

Re: Dog proximity sensor

RFID tag on the collar and a custom RFID reader coil around the entrance of the litter? Seems like that is the most targeted way to activate a deterrent.
Works for milking cows anyway.

Or if it already has an ID tag implanted try to figure out how to detect that.
by Valen
Sat Sep 15, 2018 6:44 am
Forum: Arduino
Topic: Easy Driver and geared 12v stepper having problem
Replies: 1
Views: 289

Re: Easy Driver and geared 12v stepper having problem

The easydriver has a coil current limit potentiometer. There might be too much friction for the motor to turn and might require more current to move. Don't increase the current to beyond what the steppermotor is rated for. Also the motor needs to have time to move. So the stepping clock rate should ...
by Valen
Sat Sep 15, 2018 6:36 am
Forum: Arduino
Topic: Robot Control via Ethernet Shield
Replies: 1
Views: 240

Re: Robot Control via Ethernet Shield

A meter/yard (I am guessing as the norm of length used) of normal conductive copper wire will not cause significant resistance problems for carrying signals. Power wires would need thicker wires but that too should not be a problem until it goes into multiple amps. Care must be taken they have suffi...
by Valen
Sat Sep 15, 2018 6:20 am
Forum: SparkFun Product Questions
Topic: Running dual QWIIC GPS modules
Replies: 1
Views: 120

Re: Running dual QWIIC GPS modules

Oh yea, please don't make identical threads in different places. It does not help in getting more responses. It only increases confusion in discussions.
by Valen
Sat Sep 15, 2018 6:18 am
Forum: Projects
Topic: Running dual QWIIC GPS modules
Replies: 2
Views: 117

Re: Running dual QWIIC GPS modules

I see that Sparkfun has a similar I2C bus multiplexer: https://www.sparkfun.com/products/14685

Is this the one that you mentioned using?
by Valen
Sat Sep 15, 2018 6:11 am
Forum: Projects
Topic: Running dual QWIIC GPS modules
Replies: 2
Views: 117

Re: Running dual QWIIC GPS modules

The schematic mentions the unshifted I2C adress that the GPS module would respond to. When writing or reading to it you need to shift a direction bit in front of it (most significant bit). It's probably also mentioned in the Titan 1 GPS datasheet. (not sure, only skimmed it) It does not seem to have...
by Valen
Sat Sep 15, 2018 5:40 am
Forum: Projects
Topic: WakeonShake - Flash Circuit
Replies: 1
Views: 111

Re: WakeonShake - Flash Circuit

No need to make duplicate threads. Please remove the other one or ask a moderator to do it. It causes more confusion if replied to in multiple places. 1. I don't know how many (m)Gs a stomp is. The sensor itself should not break until around 5000G. I'm pretty confident that your whole setup wil fail...
by Valen
Sat Sep 15, 2018 4:19 am
Forum: Wireless/RF
Topic: RF Remote to Receiver >Arduino for Scoreboard
Replies: 3
Views: 155

Re: RF Remote to Receiver >Arduino for Scoreboard

Often rf remotes (or IR probably also) send multiple repeats of command packets. To ensure reception chances and verify for errors in transmission. Your arduino code would need to be smart enough to recognize and verify the repeats are the same. And once the command is received verified and understo...
by Valen
Sat Sep 15, 2018 12:39 am
Forum: SparkFun Product Questions
Topic: Motion Detectors
Replies: 2
Views: 67

Re: Motion Detectors

An infrared emitter (LED) opposed to an infrared sensor on a gate through which the bees enter and exit would seem to be the simplest solution. But I do not know to which extent bees are disturbed by IR light of a certain wavelength. A microcontroller would pulse the emitter LED and would compare th...
by Valen
Fri Sep 14, 2018 11:56 pm
Forum: SparkFun Product Questions
Topic: How to power 4.5V LED ribbon with 3V micro:bit?
Replies: 10
Views: 179

Re: How to power 4.5V LED ribbon with 3V micro:bit?

Good Job. To help (future) others also interested in a similar project could you show through a simple drawn schematic how you managed to get it to work?
by Valen
Fri Aug 31, 2018 8:45 am
Forum: Projects
Topic: Trouble with a Transducer - Trying to switch it off
Replies: 10
Views: 436

Re: Trouble with a Transducer - Trying to switch it off

Yeah, never trust the order of transistor (bipolar or mosfet) pins. It's not a standard. Always consult the datasheet and make sure it is clear in the schematic and pcb layout.
by Valen
Thu Aug 30, 2018 1:49 pm
Forum: Arduino
Topic: Arduino Thermostat Multiple Outputs
Replies: 6
Views: 201

Re: Arduino Thermostat Multiple Outputs

I am sorry, I cannot give such suggestions what to buy/replace it with. I have an extremely general mental picture of what your fryer/grill entails as far a hardware goes. I've never done such a project of my own. And I live in another country so advice might not be appropriate for your's. I suggest...
by Valen
Thu Aug 30, 2018 5:20 am
Forum: SparkFun Product Questions
Topic: How to power 4.5V LED ribbon with 3V micro:bit?
Replies: 10
Views: 179

Re: How to power 4.5V LED ribbon with 3V micro:bit?

Less length means less current. So that initial transistor would be good after all. About 75 mA per foot
by Valen
Thu Aug 30, 2018 4:51 am
Forum: SparkFun Product Questions
Topic: How to power 4.5V LED ribbon with 3V micro:bit?
Replies: 10
Views: 179

Re: How to power 4.5V LED ribbon with 3V micro:bit?

Your suggested transistor seems a bit on the weak side (for a full meter of ribbon) with 200 mA absolute maximum collector current. (Beyond that it may be destroyed) Instead I'd opt for the 4 times stronger BC337: https://www.sparkfun.com/products/13689 Make sure you check the emitter, base and coll...