All Questions
Tagged with ttl microcontroller
25
questions
17
votes
2
answers
49k
views
How does TTL serial work?
I've been trying to find a good description of the TTL serial "standard" without much luck. I understand that serial transmit (TX) and receive (RX) lines idle high (at VCC) and that they drop to ...
- 2,564
10
votes
4
answers
6k
views
Buffering a Digital Microcontroller Signal for Connecting to an Optocoupler
I frequently work on projects in which I use optocouplers for isolating digital +5VDC control signals (for example, from a microcontroller) from the rest of the circuit. However, since these work by ...
- 747
5
votes
3
answers
2k
views
Driving LEDs / other small loads with a 74HC06 or similar inverter
I was recently reverse-engineering some firmware (and other bits) from a router, and spotted that the front panel LEDs were driven from a 74HC06 hex inverter gate chip rather than a proper LED driver.
...
- 10.8k
5
votes
1
answer
3k
views
how to interface HCPL-3700 optocoupler to an input pin of ATmega16L
I want to detect logic of the mains supply (230VAC, 50Hz) and feed the output of HCPL-3700 into ATmega16L. I read through the datasheet but could not understand how to calculate the resistor values. ...
- 1,495
5
votes
1
answer
671
views
Dual power supply confusing TTL serial?
Sorry for the vague title: I'm a bit of a noob at analogue electronics, more a logic &software guy. Basic problem is I'm sitting at the end of a cable with a USB powered Arduino trying to send ...
- 51
3
votes
2
answers
11k
views
Should I connect unused STM32 pins to ground?
I'm designing some circuit using STM32L152RBT6 microcontroller. I'm using STM32L-DISCOVERY scheme as a reference of good STM32 practices. I've noticed that free pins of programmer's MCU aren't ...
- 133
3
votes
4
answers
13k
views
Turn TTL output of logic IC into output capable of driving 50 ohm devices
I want to provide front-panel trigger signals with the microcontroller inside my device. The trigger signal will be fed via a 50 ohm coax cable to another device with a 50 ohm input.
A direct ...
- 653
2
votes
3
answers
591
views
Logic design to circuit -- how is it generally done?
So I've designed this CPU with purely logical components (basic logic gates), now how would I go about converting it into a circuit? I know that logical gates can be implemented using transistors, but ...
- 123
2
votes
3
answers
1k
views
How do I safely connect a 74HC00 series circuit to microcontroller?
I built and simulated a circuit out of 74HC00 series ICs and want to connect it to a microcontroller (ATmega 16).
The development board I use (Atmel STK500) supplies 4.93 V (GND to VTG and GND to ...
user29239
2
votes
2
answers
1k
views
Mux UART with 74xx Multiplexer
I have a legacy LPC MCU with 2 UARTs only. One of these UARTs is reserved for different functions such as IAP and RS232. So basically, I have one UART available only.
For an experimental project I ...
1
vote
2
answers
1k
views
Flashing program into microcontroller, usb-ttl, idea behind?
I have limited knowledge on this topic(MCUs, communication protocols, etc.). I back then worked with an STM32 MCU and did some UART(or USART, can't remember) communication between a PC and the MCU. ...
- 2,106
1
vote
3
answers
2k
views
Interfacing VC0706 with AVR Microcontroller
I am having trouble interfacing a VC0706 Camera with only an AVR Microcontroller. I am using simple serial communication but the camera does not respond. I tried connecting it with a computer but ...
- 11
1
vote
1
answer
2k
views
What are the output logic levels of this STM32?
I am struggling getting my head around the input and output logic levels, mostly the output levels of this STM32 (STM32F446xC/E).
This table shows the output logic levels as dependent on if it is a ...
- 161
0
votes
3
answers
751
views
Solid-state Electronic switch for low level signals
I need a very simple circuit to connect a signal to one of two ways like this:
My com signal is actually a microphone input, so very low voltage, <200mV, how can I make a solid state switch that ...
- 507
0
votes
2
answers
583
views
How do I know if it's RS232 levels or TTL levels
I have a random device: GT MEDIA V8 Finder Pro. I would like to communicate over its console port.
Here are some pictures of its mainboard. Here is the area around the console connector:
I have no ...
