0
votes
2answers
58 views

IC for 4 Kbytes of RAM [on hold]

Is there a Memory IC for 4Kbytes of RAM? I'm trying to make a schematic capture in Proteus and I need a Memory IC for 4Kbytes of RAM, I've searched throughout the library and I can't find one, tried ...
20
votes
6answers
5k views

Why do microcontrollers have so little RAM?

Maybe this is more of a perceptional problem, but it seems like microcontrollers have advanced by leaps and bounds in the last 20 years, in almost all regards, higher clock speed, more peripherals, ...
0
votes
1answer
79 views

Microcontroller freezes (or doesn't) when plugged into different outlets in my home

I have an ARM development board (Marvell ARMADA XP CPU) and depending on which plug outlet I plug the system into, the system will freeze up after a few minutes or not. I found that plug outlets in ...
2
votes
0answers
143 views

Integrated LED + Resistor + Transistor

Most designers when are controlling an LED have to make the same old circuit of Vcc -> Resistor -> LED -> Transistor (you need the transistor in case your ...
0
votes
1answer
56 views

Controlling high rating DC motor

In a robot, I need to use a (24 volts 5-7 amp) DC motor, which should be controlled by a microcontroller. Now, will I get a motor driver IC for such a motor? If not, what kind of circuit will help? I ...
1
vote
0answers
46 views

at89c51 power supply [duplicate]

I am making a project using at89c51. I used my mobile charger (output: 5V, 1A) as the power supply. Will my IC get damaged due to the high current? I asked cause, without loading the program I ...
0
votes
3answers
84 views

Is there any way to interface 4x4 matrix keypad using 2 IO lines

I have two IO lines and wants to interface 4x4 matrix keypad. Using MUX ICs I need 4 IO lines. Is there any method to achieve it using 2 IOs?
11
votes
4answers
840 views

Reason of multiple GND and VCC on an IC

What is the reason that most of ICs (e.g. MCU) has multiple (A/D)GND and (A)VCC pins? If it is to increase performance of an IC, how does it help to performance? or is it easier for the IC designer ...
4
votes
2answers
256 views

Cascading several SPI devices

Is it possible to cascade several different ICs on the same data line, in order to use less CS pins, by tying the digital output of each to the digital input of the next? I am familiar with this ...
0
votes
3answers
177 views

What exactly is a microcontroller?

Can an optical mouse sensor chip (System On Chip) which has a digital signal processor, Serial I/O, and a set of registers be considered as a Micro-controller?
1
vote
2answers
92 views

Is it necessary to connect all power pins to power pic16f877a [duplicate]

I am using a pic16f877a for a project and I noticed that there are two VDD and VSS pins. I wanted to know weather all 4 pins had to be connected to power or just one VDD and one VSS pin. A circuit I ...
2
votes
1answer
128 views

What is the difference between an I/MM, E/MM and H/MM package?

I'm looking into the PIC18F25K80 as a new microcontroller for my company, but ran into an issue with supplier quantities. The PIC18F25K80-I/MM-ND that I originally selected seems to be very hard to ...
0
votes
0answers
221 views

Searching for specs on IC CX2829

I'm looking for a datasheet on an IC. CX2829 (SOT23 6 pin). I think it's a controller. I see it used on some LED lights that have modes (low, high, blinking). Google keeps leading me to the same dead ...
2
votes
1answer
137 views

What is the function of the given IC?

Which Type of IC is this one ? what is its function
2
votes
0answers
103 views

What components do I need to wirelessly transmit a small signal via Bluetooth? [closed]

So I'm doing a project trying to create a wireless Electrocardiogram (ECG or EKG) system. I built the hardware, connected it to a human subject, and it works perfectly - you can see the heartbeat ...
9
votes
3answers
858 views

Are there any types of DC motors that self-lock themselves?

I have a small DC gear motor which spools a plastic line. Once I've engaged the motor to tighten the line, I want to lock it in place so that the line doesn't unspool. I would then like it to remain ...
3
votes
1answer
1k views

Connecting microcontroller 3.3V output to relay using ULN2803A

I have a need to connect an ARM micro-controller with 3.3V digital output pins to a few 12V solenoid water valves. I figured that I can use a ULN2803A for this task. The internal circuit for each ...
4
votes
1answer
142 views

Can low current/voltage damage ICs?

I'm a total newbie at this, and I'm trying to make my Arduino-mini work on batteries. Is it 100% safe if my arduino (or other components) receive like the minimum current to the point it's about to ...
-3
votes
2answers
370 views

Instructing the Program Counter (PC) to increment [closed]

I am building an 8bit computer from TTL, in regards to the Program Counter, sometimes I may not want it to increment on each clock pulse, with that in mind, how would I instruct it to increment? The ...
-3
votes
1answer
395 views

SAP-1/8 Bit Computer MAR/RAM [closed]

I am looking to develop my own 8 bit computer with a really basic instruction set. I do not know however what the best IC is to be able to perform this job. Could I utilise an Arduino to act as the ...
1
vote
0answers
531 views

SAP-1 (Simple as Possible) W Bus

I'm currently investigating the SAP-1 to build in order to grasp a really good understanding of simple 8 bit computers. There are a few questions that I would like clearing up. What exactly is the ...
3
votes
2answers
228 views

Why are some IC's programmable in circuit, but others aren't?

Why are some IC's programmable while still connected in a system/circuit, but others aren't? What's the determining factor(s) for whether a chip can or cannot? This question stems from my research on ...
3
votes
2answers
210 views

Creating a Programmable ROM Logic / Schematic

I would like to know if it is possible to create a programmable ROM from transistors and logic gates? Or, is it possible to create a type of persistent storage similar to Flip Flops?
1
vote
2answers
636 views

How does the 4017B Decade Counter work?

I am currently looking at a 4017B Decade Counter Data Sheet. As I look at the Logic Schematic for this IC (http://www.ti.com/lit/ds/symlink/cd4017b.pdf) I can see several sqaure boxes label D, C, ...
1
vote
1answer
233 views

XOR gate with NAND

I am attempting to build an XOR gate with NAND ICs. This schematic is how I am wiring up the IC (I know the schematic is a little confusing but I tried to construct it best I can). I am ...
1
vote
1answer
157 views

Bottom half of IC appears not working?

I have a NAND logic gate, the top 6 pins appear to be working fine (4x Input, 2x Output) However the bottom 6 pins on the IC appear not to work. I was testing the IC via an LED, connecting two high ...
1
vote
1answer
103 views

What kind of failure would I see in moisture sensitive parts?

I am reflowing a design using an electric skillet. When the uC and LEDs arrived they were in moisture sensitive packaging. They were in sealed bags with moisture indicator cards. After I opened them I ...
-1
votes
3answers
267 views

Reasons of more than one ground pin in L293

Why in L390 they provide four pins for the ground and the heat sink? For heat sink,is only one pin is not sufficient? Here is the datasheet http://www.ti.com/lit/ds/symlink/l293d.pdf
1
vote
2answers
772 views

IC buffer like 4066 with 8 or 16 switches

I have a computer and two monitors. I want to build a device so that I can switch between to monitors. I would use buffers (like 4066) and a microcontroller. Is there any buffer like 4066 with 16 or 8 ...
14
votes
2answers
770 views

How did handheld video games from the 70's and 80's work?

I'm curious about how the early handheld video games from the 70's and 80's worked. You know, those small games with a LCD display with "fixed elements" meaning it was hard wired for one (or a small ...
2
votes
2answers
689 views

Control multiple LEDs using an IC and PC/Linux thru USB

I've already tried to search this topic but all Google results said that this isn't possible. Is there any chance of controlling multiple LEDs using a PC/Linux, through USB? The diagram might look ...
2
votes
2answers
234 views

What can I do as a student to be a better candidate for a hardware design job? [closed]

If you were looking to hire a student still in school for an internship position at a high-tech company (say, Microsoft, Apple, or Google) for hardware design. What kind of skills would you be looking ...
3
votes
2answers
604 views

Identify an IC Found in a Garage Door Opener

Inside a defunct garage door opener I found this IC: I tried searching for 33192C with variations of 'datasheet' and such keywords, but I got routed to the usual datasheet farms who are happy to ...
5
votes
3answers
460 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. ...
2
votes
3answers
781 views

How to identify faulty or Fake (Duplicate) ICs?

I am developing an application on LPC2138. I prepared prototype using a standard development board. After completion, I shifted to final board. But I am not able to download any program my LPC2138. ...
-1
votes
1answer
213 views

Mobile Server Uplink / GPS Coordinate Packet? [closed]

I'm completely uneducated when it comes to more advanced electrical engineering. I understand the very basics. I have over 12 years in software development / programming, but would like to extend my ...
3
votes
3answers
836 views

IC/Microcontroller logic gates

I am a software developer trying to understand how computers work at a lower level. I understand that there is a difference between an Integrated Circuit, a MicroProcessor and a MicroController. A ...
1
vote
1answer
321 views

Frequency modulation and communication between two microcontrollers

I have good progamming skills and concepts on 8051 microncontroller. People suggest me to work on PIC and ARM micro-controllers but I want to make some small projects on 8051 and later move on to ...
2
votes
2answers
618 views

Building and Driving a Stepper Motor

I don't know whether or not I'll actually build one yet, as to do so properly would require ball bearings, metal working, etc and frankly the fund's just aren't available right now(have yet to ...
1
vote
1answer
739 views

Arduino to act as a switch for a remote

I have a wireless remote control for a light. It runs with a 12V battery. It has two mini Omron type B3F momentary ON switches (mini push-button switches). One button is for Light ON, the other for ...
4
votes
1answer
509 views

Can I connect ICs directly together

This is probably answered elsewhere but I can't seem to find it. I have a circuit which uses a Mega8 to drive a couple of ICs as shown in the diagram below. The ISP connectors in the diagram are: ...
0
votes
1answer
776 views

48VDC SLA charger from 12VDC supply design help

I am in the process of designing a 48 VDC (comprised of 4 x 12 VDC) lead-acid battery charger, with an input voltage of 12 VDC. 1W - 2W output is sufficient, and relatively high efficiency with low ...
1
vote
1answer
302 views

Driving a LCD from a Basic Stamp 2 microcontroller

I'm not able to drive a UP018D01 LCD Display (www.ic72.com/pdf_file/u/590916.pdf) with my Basic Stamp II microcontroller. The first step I'm trying to do is to switch ON the LCD backlight. According ...