Tagged Questions

0
votes
2answers
58 views

How to block/allow an i2c data signal to pass on to another device

I have three devices which I'm working on and one of them needs to control i2c communication between the other two. Each of the devices is based on an AtMega or AtTiny chip. The Controller (based on ...
0
votes
1answer
59 views

Single FET Bus Switch schematic in EAGLE

I've added a SN74CBT1G384DBV into my schematic in Eagle (which I want to use to enable/disable a logic signal line). Once placed into the schematic there only appear to be connection points for VCC ...
4
votes
1answer
258 views

Selecting proper vales of Rb, Re and and Rbe in a NPN transistor emitter follower configuration?

I need to gate a TTL Tx pin @115000bps as the chipset that drives the RxTx lines do not implement UART BREAK for arbitrary time periods. As a quick hack I have come up with the following ...
0
votes
1answer
100 views

Octal DIP Switch Digital '0'?

I've been playing around with logic gates and RAM chips and stuff the past week or so, but I can't figure out how to get a DIP switch to represent a digital '0' while still being able to represent '1' ...
1
vote
2answers
266 views

Switch hookup with relay (arduino)

Hey all i have the following 5v relay board: Please ignore the light bulb hook up. That was an example on the website that had the same relay :) And i am looking to hook one of the relays up to a ...
7
votes
3answers
498 views

Using SPST switch as digital input?

I am new to "electrical engineering" and I am working on a little arduino project. I want to have a SPST switch be used as a digital input on the board. I have one of the switch leads connected to ...
3
votes
2answers
465 views

Digital Switching for Audio

I want to be able to digitally switch the input of a line-level preamplifier. I was considering using relays to physically connect or disconnect each source to the input of the amp, which would be ...
6
votes
2answers
268 views

How to connect external switches to this circuit board

I am circuit bending a walkie-talkie to move some of the switches around and embed it in a shoe. One part I'm not sure about is how to replace some momentary switches on the front with external ...
0
votes
0answers
35 views

Digitally programmable switch using minimum space (without relays) [duplicate]

Possible Duplicate: How to short two nodes electronically I want to make a pcb containing about 32 switches (that do a physical connection between wires) each can be programmed digitally ...
1
vote
5answers
447 views

Would this button trigger alarm circuit work?

This is a dead easy question for most of you! But I'm relatively new to circuit design, so I'd just like to ask whether this circuit might work (at all!) Here's a picture of the circuit ...
1
vote
2answers
304 views

DPDT switch for on/off

Hey all, I'm fiddling with a breadboard to make some logic gates and instead of buying spst switches, I bought dpdt switches because they were the only ones that would fit in the board. :/ Can I ...
1
vote
4answers
583 views

How to set a digital out to 24V Vcc

I want a curcuit with 3.3V and 24V supply. The micro will use the 3.3V supply, which needs to be able to set multiple industrial 24V digital outputs. My plan was a simple op amp, but as far as I know ...
5
votes
7answers
4k views

Make a momentary switch control a toggle

What are the simplest, cheapest, smallest ways to make a momentary switch control a toggling output or latching momentary switch? In other words, the output is continuously low, and when you ...